ABSTRACTFeather pecking (FP), a damaging behavior where laying hens peck and pull at feathers of conspecifics, is multifactorial and has been linked to numerous behavioral and physiological characteristics. The gut microbiota has been shown to influence host behavior and physiology in many species, and could therefore affect the development of damaging behaviors, such as FP. Yet, it is unknown whether FP genotypes (high FP [HFP] and low FP [LFP] lines) or FP phenotypes (i.e., individuals differing in FP, feather peckers and neutrals) differ in their gut microbiota composition. Therefore, we identified mucosa-associated microbiota composition of the ileum and cecum at 10 and 30 wk of age. At 30 wk of age, we further identified luminal microbiota composition from combined content of the ileum, ceca, and colon. FP phenotypes could not be distinguished from each other in mucosa-associated or luminal microbiota composition. However, HFP neutrals were characterized by a higher relative abundance of genera of Clostridiales, but lower relative abundance of Lactobacillus for the luminal microbiota composition compared to LFP phenotypes. Furthermore, HFP neutrals had a higher diversity and evenness for the luminal microbiota compared to LFP phenotypes. FP genotypes could not be distinguished from each other in mucosa-associated microbiota composition. Yet, FP genotypes could be distinguished from each other in luminal microbiota composition. HFP birds were characterized by a higher relative abundance of genera of Clostridiales, but lower relative abundance of Staphylococcus and Lactobacillus compared to LFP birds. Furthermore, HFP birds had a higher diversity and evenness for both cecal mucosa-associated and luminal microbiota compared to LFP birds at adult age. In conclusion, we here show that divergent selection on FP can (in)directly affect luminal microbiota composition. Whether differences in microbiota composition are causal to FP or a consequence of FP remains to be elucidated.

ABSTRACTPost hatch muscle growth and the repair or regeneration of muscle after myofiber injury is mediated by satellite cells. Satellite cells proliferate, migrate, differentiate, and fuse with growing or regenerating myofibers. The proliferation and differentiation of satellite cells are affected by nutrition, but it is unknown how nutrition impacts satellite cell migration. The objective of the study was to determine the effect of a nutrient restriction on satellite cell migration. Satellite cells from the pectoralis major muscle of 1 and 49-day-old Randombred Control Line 2 turkeys were grown in culture, and migration was measured using a wound healing assay. Nutrient restrictions of 0, 5, 10, and 20% of the standard culture medium were applied starting immediately after scratch or 24 h prior to scratch. Nutrient restrictions of 5 and 20% increased 1 D satellite cell migration at 6 h post scratch compared to 1 D satellite cells with standard culture medium but had no effect after 12 h post scratch. Nutrient restrictions started 24 h prior to scratch increased 1 D satellite cell migration at 6 and 12 h post scratch compared to nutrient restrictions started immediately after scratch. The migration of 49 D satellite cells was not affected by the percentage or timing of the nutrient restriction. These data suggest that nutrition has only a minor effect on the migration of turkey pectoralis major muscle satellite cells. Therefore, the influence of nutrition on satellite cell migration is likely not an important factor for evaluating poultry diet formulations to optimize muscle growth and structure for improved meat protein and fat content as well as meat texture.

ABSTRACTLow pathogenicity avian influenza (LPAI) H9N2, highly pathogenic avian influenza (HPAI) H5N1, and H5N8 circulate in Egyptian poultry and cause veterinary and public health burdens. In response, AIV vaccines are commonly used. The main objective of this study was to develop a broad, cross-protective, trivalent vaccine based on circulating AIVs in Egypt. We generated highly replicating avirulent AIVs, H5N1, and H5N8, to be used in combination with H9N2 strain for the generation of an inactivated vaccine. Immunogenicity and protective efficacy of this vaccine were tested. Results showed that a single immunization dose enhanced humoral immune responses giving full protection against challenges with LPAI H9N2, HPAI H5N1, and H5N8 viruses. This efficacious vaccine will reduce the cost of vaccination for poultry growers and is expected to be effective in the field as it is based on contemporary viruses currently in circulation among Egyptian poultry.

ABSTRACTThis study investigated the hypothesis that dietary supplementation of leucine (Leu) above actual recommendations activates protein synthesis and inhibits protein degradation pathways on the molecular level and supports higher muscle growth in broilers. Day-old male Cobb-500 broilers (n = 180) were allotted to 3 groups and phase-fed 3 different corn-wheat-soybean meal-based basal diets during periods 1 to 10, 11 to 21, and 22 to 35 D. The control group (L0) received the basal diet which met the broiler's requirements of nutrients and amino acids for maintenance and growth. Groups L1 and L2 received basal diets supplemented with Leu to exceed recommendations by 35 and 60%, respectively, and isoleucine (Ile) and valine (Val) were supplemented to keep Leu: Ile and Leu: Val ratios fixed. Samples of liver and breast muscle and pancreas were collected on days 10, 21, and 35. The gene expression and abundance of total and phosphorylated proteins involved in the mammalian target of rapamycin pathway of protein synthesis, in the ubiquitin-proteasome pathway and autophagy-lysosomal pathway of protein degradation, in the general control nonderepressible 2/eukaryotic translation initiation factor 2A pathway involved in the inhibition of protein synthesis, and in the myostatin–Smad2/3 pathway involved in myogenesis were evaluated in the muscle, as well as expression of genes involved in the growth hormone axis. Growth performance, feed intake, the feed conversion ratio, and carcass weights did not differ between the 3 groups (P > 0.05). Plasma concentrations of Leu, Ile, and Val and of their keto acids, and the activity of the branched-chain α-keto acid dehydrogenase in the pancreas increased dose dependently with increasing dietary Leu concentrations. In the breast muscle, relative mRNA abundances of genes and phosphorylation of selected proteins involved in all investigated pathways were largely uninfluenced by dietary Leu supplementation (P > 0.05). In summary, these data indicate that excess dietary Leu concentrations do not influence protein synthesis or degradation pathways, and subsequently do not increase muscle growth in broilers at fixed ratios to Ile and Val.

ABSTRACTEggs are widely recognized as a highly nutritious food source that offer specific health benefits for humans. Eggs contain all of the proteins, lipids, vitamins, minerals, and growth factors necessary for embryonic development. In particular, egg white and yolk proteins are considered functional food substances because they possess biological activities such as antimicrobial, antioxidant, metal-chelating, antihypertensive, anticancer, and immunomodulatory activities. Peptides produced via processes such as enzymatic hydrolysis, fermentation by microorganisms, and some chemical and physical treatments of egg proteins have been shown to enhance the functional properties and solubility of these peptides. Peptide activity is strongly related to amino acid sequence, composition, and length. At present, cancer remains among the leading causes of mortality worldwide, and therefore research aimed at developing new treatments for cancer immunotherapy is of great interest. The present review focuses primarily on the anticancer and immunomodulatory activities of egg proteins and their peptides and provides some insight into their underlying mechanisms of action. A number of egg proteins and peptides have been reported to induce apoptosis in cancer cells, protect against DNA damage, decrease the invasion ability of cancer cells, and exhibit cytotoxic and antimutagenic activity in various cancer cell lines. Furthermore, egg proteins and peptides can stimulate or suppress pro- or anti-inflammatory cytokines, as well as affect the production of inflammatory mediators in a variety of cell lines. In addition, the composition of eggs and the processes of egg proteins and peptides production will be discussed.

ABSTRACTThe objective of this experiment was to investigate the effects of various dietary concentrations of vitamin D3 (D3) on pullet and laying hen performance, eggshell quality, bone health, and yolk D3 content from day of hatch until 68 wk of age. Initially, 440 Hy-line W36-day-old chicks were randomly assigned to 5 dietary treatments: 1,681 (control); 8,348; 18,348; 35,014; 68,348 IU D3/kg. At 17 wk of age, pullets were assigned to experimental diets with 12 replicate groups of 6 birds. At 17 wk of age, pullets fed diets containing 8,348 and 35,014 IU D3/kg had an increased bone mineral density in comparison to the control fed birds (P ≤ 0.01). Body weights of pullets fed the diet with 68,348 IU D3/kg were lower than other treatments (P ≤ 0.01). Hen-housed egg production (HHEP) of hens fed the 35,014 IU D3/kg diet was increased in comparison to control-fed hens (P ≤ 0.01), whereas HHEP of those fed 68,348 IU D3/kg diet was reduced in comparison to all other treatments (P ≤ 0.01). Shell breaking strength of eggs from hens fed 8,348, 35,014 and 68,348 IU D3/kg was increased in comparison to eggs from control-fed birds (P ≤ 0.01). Fat-free tibia ash content of hens fed any of the diets supplemented with D3 (8,348 to 68,348 IU D3/kg) was increased in comparison to control-fed hens (P ≤ 0.05). Yolk D3 content increased linearly with dietary D3 and the D3 transfer efficiency for the control, 8,348 IU, 18,348 IU, 35,014 IU, and 68,348 IU D3 treatments were 8.24, 10.29, 11.27, 12.42, and 12.06%, respectively. These data suggest that supplementation of dietary D3 up to 35,014 IU D3/kg feed maintained if not increased laying hen performance and enhanced pullet and laying hen skeletal quality as well as yolk D3 content and eggshell quality. Feeding pullets at a higher level 68,348 IU of D3 resulted in reduced growth and ultimately decreased performance of laying hens.

ABSTRACTAn empirical linear mixed model was derived to describe metabolizable energy (ME) partitioning in broiler breeder hens. Its coefficients described ME used for total heat production (HP), growth (ADG), and egg mass (EM). A total of 480 Ross 308 hens were randomly and equally assigned to 2 treatments: precision feeding (PF) and conventional daily-restricted feeding (CON) from 23 to 34 wk of age. The PF system allowed birds to enter feeding stations voluntarily at any time, weighed them, and provided access to feed for 60 s if their BW was less than the breeder-recommended target BW. The CON birds were fed daily each morning. Energetic efficiency of hens was evaluated using residual feed intake (RFI), defined as the difference between observed and predicted ME intake (MEI). The energy partitioning model predicted (P < 0.05): MEI = A × BW0.67 + 1.75 × ADG + 0.75 × EM + ϵ. The coefficient A, a vector of age-specific HP, was 142 kcal/kg0.67/d; the energy requirement for growth and EM was 1.75 and 0.75 kcal/g, respectively. For the CON and the PF hens, respectively, MEI was 366 and 354 kcal/d (P = 0.006); RFI was –5.9 and 6.7 kcal/d (P = 0.009); HP% was 85.5 and 87.7 (P < 0.001); hen-day egg production (HDEP) was 65.5 and 55.2% (P < 0.001). Although the CON hens had higher MEI, the model predicted lower HP%; thus, CON hens had more nutrients available for egg production, increased egg production, and were more energetically efficient than the PF hens. The decreased egg production by the PF hens was likely due to these hens receiving production-related feed increases after an egg was laid. However, feed allocation increases for the CON hens resulted in increasing MEI for all CON hens at the same time. Therefore, the PF hens had lower MEI and lower HDEP than the CON hens.

Published data on the beneficial effect of short-term administration of thyroxine (T4) in broiler breeder hens to reduce the ascites incidence in their progeny chicks raises the question as to what extent might the long-term maternal administration of T4 affect the blood hematological and biochemical attributes in breeder hens. A total of 70 broiler breeder hens (47-wk-old) were randomly allotted to control or thyroxine treated (T4) groups. Pure T4 (0.3 mg/bird per day) was orally administered to T4 birds for 14 successive weeks, whereas the control group received the drinking water only. Blood samples were obtained from the brachial vein prior to the initiation of the trial as well as weeks 50, 53, 55, 57, 59, and 61 of age. Body weight was decreased but egg production was not affected by T4 treatment. Plasma concentration of T4, but not triiodothyronine (T3), was increased in T4-treated hens (P < 0.05). The total number of leukocytes and erythrocytes were also higher in T4 birds. A significant effect of time was observed for erythrocyte number and plasma cholesterol concentration (P < 0.05). The long-term administration of T4 did not affect the concentrations of serum calcium and plasma total protein, albumin, globulin, cholesterol, triglyceride, high density lipoprotein, low density lipoprotein, very low density lipoprotein, alanine amino transferase, and aspartate amino transferase (P > 0.05). However, serum concentrations of phosphorus, glucose, and alkaline phosphatase were higher in T4 hens as compared to their control counterparts. In spite of differences in circulatory concentrations of a number of traits between the experimental groups, the recorded values were within their reference ranges. Therefore, the administration of T4 for an extended period of time had no apparent adverse effect on the clinical profile in subjected hens, which may practically support the implementation of this preventative treatment as an approach to decrease the ascites incidence; however, a lower incidence rate in the progeny chicks produced from hens receiving T4 for long-term periods of time remains to be elucidated.

Phytase is of importance to the poultry industry because of its ability to hydrolyze phytate and release phosphorus (P) for use by poultry. However, the effect of age on phytase efficacy is not fully understood. A total of 864 day-old broiler chicks were used to investigate the effect of age and feeding length on phytase efficacy using growth performance, mineral utilization, and tibia ash as response criteria of evaluation. The experiment was arranged as a 3 × 2 × 2 factorial in a randomized complete block design with 3 diets including; a positive control (PC; 0.4% non-phytate P (nPP)), a negative control (NC; 0.2% nPP) and a NC diet supplemented with phytase at 2,000 FYT/kg; 2 ages (i.e., days 14 and 22); and 2 feeding lengths (i.e., 2 and 5 D) with 8 replicates each. Birds fed the NC had decreased (P < 0.01) body weight gain and feed efficiency compared with birds fed the PC regardless of age or feeding length. Similarly, birds fed the phytase-supplemented diet had improved (P < 0.01) performance as compared to birds fed the NC regardless of age. There were no significant differences in P utilization between birds fed for 2 to 14 D or 22 D and birds fed for 5 D to both ages. However, phytase was more efficacious at day 14 than day 22 when mineral utilization was considered because the super dose of phytase elicited greater response in birds fed the phytase supplemented diet for 2 D until day 14. In contrast, percentage tibia ash improved (P < 0.01) in birds fed phytase supplemented diet for 5 D at both ages as compared with birds fed for 2 D. In conclusion, testing phytase products, even at high doses, for 2 D during the second week in the life cycle of broiler chicks, can be recommended from the results of this study.

ABSTRACTThe interaction between inclusion of fibrous ingredients and bird type on the coefficient of apparent ileal digestibility (CAID) of nutrients and energy utilization was investigated in the current study. A 2 × 3 factorial arrangement of treatments was utilized with 2 fiber contents (10.3 and 19.3 g/kg neutral detergent fiber) and 3 bird types (broilers, pullets and layers). The low-fiber diet was based on corn and soybean meal, and the high-fiber diet was developed by the inclusion of palm kernel meal, canola meal, and oat hulls. Titanium dioxide was used as an inert marker to calculate the CAID. The digesta were collected from the terminal ileum following the feeding of experimental diets for 7 d. Significant interactions (P < 0.05) between dietary fiber content and bird type were observed for the CAID of DM, starch, fat, neutral detergent fiber and energy, and AMEn. In general, the CAID coefficients were higher in broilers, intermediate in pullets, and lowest in layers at both fiber contents. The CAID of nutrients in the 3 bird types was higher (P < 0.05) in the high-fiber diet than in the low-fiber diet, but the magnitude of responses differed. Layers showed markedly higher digestibility responses to increased dietary fiber content compared to broilers and pullets. There were interactions (P < 0.05 to 0.001) between the dietary fiber content and bird type for the CAID of nitrogen and all amino acids, except for Asp and Lys. The CAID of Asp and Lys was highest (P < 0.05) in broilers, intermediate in pullets, and lowest digestibility in layers. The CAID coefficients of nitrogen and amino acid increased with increased fiber content, with distinctly greater responses in layers compared to broilers and pullets. Overall, layers showed greater digestibility of nutrients in response to the increased fiber content, suggesting that layers require high-dietary fiber contents to efficiently utilize nutrients compared to broilers and pullets.

ABSTRACTThis study was conducted to investigate the effects of dietary bamboo leaf extract (BLE) on growth performance, meat quality, oxidative stability, and nuclear factor erythroid 2-related factor 2 (Nrf2) related gene expression of breast meat in broilers. A total of 576 one-day-old male Arbor Acres broilers were divided into 6 groups. The control group (CTR) was fed basal diet, while BLE1, BLE2, BLE3, BLE4, and BLE5 were fed basal diet supplemented with 1.0, 2.0, 3.0, 4.0, and 5.0 g BLE per kg feed, respectively. Compared with the CTR group, BLE2 and BLE5 increased average daily feed intake from 1 to 21 D and 22 to 42 D (P < 0.05), BLE1 and BLE2 improved average daily gain (ADG) and feed to gain ratio from 22 to 42 D (P < 0.05). Throughout the trial period, the highest body weight and favorable ADG and feed to gain ratio were observed in the BLE2 group. The drip loss at 24 h and pH at 45 min postmortem of breast meat were linearly improved by BLE supplementation (P < 0.05). Shear force was significantly lower in BLE2 and BLE3 than that in CTR group. Increasing supplementation of BLE linearly improved free radical scavenging capacity and decreased malondialdehyde content of breast meat during 12 D of storage (P < 0.05). Total antioxidant capacity and glutathione peroxidase activity were linearly increased by BLE supplementation (P < 0.05). Compared with the CTR group, the mRNA expression of Nrf2 and glutathione peroxidase in BLE3, BLE4, and BLE5 groups was significantly promoted, and glutathione S-transferase gene expression was increased in BLE2, BLE4, and BLE5 (P < 0.05). The highest (P < 0.05) heme oxygennase-1 gene expression was observed in BLE5. In conclusion, broiler supplemented with BLE improved growth performance and meat quality, BLE supplementation might activate Nrf2 pathway to alleviate lipid oxidation and increase antioxidant capacity of breast meat. The dosage of 2.0 to 3.0 g/kg BLE in broiler diet was recommanded.

ABSTRACTIn a previous study, we examined the synergistic effects of the dietary supranutritional supplementation with vitamin E, vitamin C, and Se on the in vivo antioxidative status of broilers under conditions of dietary oxidative stress induced by feeding a diet high in n-3 PUFA. In this study, we examined the effect of their inclusion on the quality characteristics and oxidative stability of raw or cooked meat, both fresh or after a long-term frozen storage. Four hundred 21-day-old Ross 308 male broilers were allocated to 5 experimental groups fed 5% linseed oil-enriched finisher diets (days 21 to 40): Cont (recommended levels of vitamin E, C, and selenium), +E (200 IU vitamin E/kg feed), +C (250 mg vitamin C/kg feed), +Se (0.2 mg selenium/kg feed), or +ECSe (concentrations as in the sole supplementation, combined). Animal performance and carcass characteristics were monitored at the age of 40 D. Breast meat samples of 12 chickens per group were analysed fresh, fresh after frozen storage, cooked fresh, and cooked after frozen storage (2 × 2 factorial design) for parameters of meat quality (water-holding capacity—WHC, pH, and color) and oxidative stability (concentrations of vitamin E, malondialdehyde—MDA, antioxidant capacity of the water-soluble compounds—ACW, and fatty acid composition).Vitamin E alone (+E) and combined with Se and vitamin C (+ECSe) increased the α-tocopherol concentration in breast muscle, and showed similar protective effects against lipid peroxidation measured as MDA regardless of the frozen storage or cooking. The sole supplementation of vitamin C or selenium showed no effects on the meat quality parameters. In conclusion, the dietary supranutritional inclusion of vitamin E inhibited the lipid peroxidation in fresh, frozen stored, cooked fresh, and frozen stored meat in broilers fed with diets rich in n-3 PUFAs. Even though no clear synergistic effects of the supranutritional supplementation of vitamin C and Se with vitamin E were detected, their dietary inclusion did not negatively affect broilers carcass and meat quality parameters.

ABSTRACTGenistein (GEN), a type of soy isoflavones, is similar to estrogen structurally and functionally. The effects of dietary gen on the reproductive performance and bone status of breeder hens were investigated. A total pf 720 laying broiler breeder (LBB) hens were randomly allocated into 3 groups with supplemental dietary GEN doses (0, 40, 400 mg/kg). Each treatment has 8 replicates of 30 birds. The results indicated that supplemental GEN significantly improved the egg production and eggshell strength of LBB hens. Dietary GEN was deposited into the egg yolk, which decreased malonaldehyde in the follicle and egg yolk. The levels of vitellogenin (VTG), progesterone, and follicle-stimulating hormone in the serum of GEN-treated groups were elevated compared with the control group. Furthermore, GEN treatment downregulated the mRNA expression of insulin-like growth factor binding protein in the fallopian tube, whereas 40 mg/kg GEN treatment upregulated estrogen receptor α expression. Both the mRNA expression of VTG-II in the liver and mRNA expression of amphiregulin in the fallopian tube were upregulated after 40 and 400 mg/kg GEN treatment. In the 400 mg/kg GEN-treated group, the levels of calcitonin and alkaline phosphatase in the serum were increased compared with the control group, which was consistent with the increased levels of calcium and phosphorus in the tibia. Supplemental GEN (400 mg/kg) improved the tibia strength of LBB hens, whereas 40 mg/kg GEN had better effects on laying performance. In summary, dietary GEN could improve the egg production and quality, as well as the bone status of LBB hens during the late egg-laying period.

ABSTRACTChanging dietary protein and amino acids may impact intestinal barrier function. Experiments were conducted in broiler chickens to evaluate supplementation of L-glutamine, glycine, and L-arginine in a reduced protein (RP) diet. Experiment 1 examined the growth performance of broilers fed 5 dietary treatments: 1) a standard diet; 2) an RP diet (193.9 g/kg CP in grower and 176.9 g/kg CP in finisher); 3) RP diet supplemented with 10 g/kg L-Gln; 4) RP diet supplemented with 10 g/kg Gly; 5) RP diet supplemented with 5 g/kg L-Arg. Each experimental diet was replicated 6 times with 10 birds per replicate. In a subset of 96 birds, experiment 2 tested the 4 RP diets with and without dexamethasone (DEX) to induce leaky gut. Each diet was replicated 24 times. Fluorescein isothiocyanate dextran (FITC-d) was used to test intestinal permeability (IP). Gene expression of selected tight junction proteins in ileal and jejunal tissues was assayed by quantitative PCR. From day 7 to 35, the RP diet increased feed intake (FI) (P < 0.05) and body weight gain (BWG) compared with the standard diet while Gln reduced FI and BWG (P < 0.05) compared with RP. Gly had no effect on BWG or FCR. Supplementation of Arg improved FCR from day 21 to 35 and day 7 to 35. In experiment 2, Arg tended to lower FITC-d (P = 0.086). DEX increased passage of FITC-d into the serum (P < 0.001). The villi surface area was increased in birds fed higher Arg (P < 0.05). DEX and diet interacted (P < 0.01) for jejunal claudin-3 mRNA level where DEX upregulated claudin-3 for all diets except the Arg diet. In summary, with a moderate reduction of protein, satisfactory performance can be obtained. Although Gln and Gly had no demonstrable positive effect on IP and performance of broilers, increasing the dietary Arg by approximately 140% improved FCR and showed indications of improved intestinal barrier function of birds fed an RP diet under a stress model.

ABSTRACTWith intensive selection for meat production in broilers, excessive fat accumulation is also accompanied and causes economic concerns. Folic acid was reported to be involved in lipid metabolism. The present study was conducted to investigate the role of folic acid in reducing abdominal fat deposition. A total of 105 one-day-old healthy Arbor Acres broilers were randomly distributed into 3 treatments, including the control (Con), saline-perfusion group (NS), and folic acid perfusion group (FA). The growth performance, biochemical characteristics in serum, and lipid metabolism in the liver and abdominal fat tissues were evaluated. Results have shown that folic acid significantly reduced abdominal fat percentage (P < 0.05) and had no effects on BW, ADFI, ADG, and FCR (P > 0.05). Serum triglycerides (TG), total cholesterol (TC), and alanine aminotransferase (ALT) levels were lower in FA group but albumin concentration was higher (P < 0.05). Hepatic ACC, SCD, ELOVL6, PI3K, LDLR, HMGCR, and ABCA1 mRNA abundance were all down-regulated in FA group (P < 0.05) when compared with the Con and NS groups, while CPT1 and PPARα were not affected. In addition, MTTP mRNA abundance was higher in the liver of birds subjected to folic acid (P < 0.05). There was no difference about TG deposition in the liver among all groups based on hematoxylin−eosin (HE) and Oil Red O staining. On the other hand, ELOVL6, PPARγ, IGF1, and TGFβ2 expression were notably decreased in the abdominal fat in FA group (P < 0.05). In conclusion, our data demonstrated that folic acid has reduced abdominal fat percentage by decreasing hepatic lipogenesis and suppressing adipocytes proliferation and differentiation. And the inhibiting effect of adipocytes might be mediated by IGF1 and TGFβ2 down-regulation.

ABSTRACTThis study investigated the effects of fermented soybean meal (FSBM) with or without mannan-oligosaccharide (MOS) prebiotic on growth performance, digestive functions, and hepatic IGF-1 gene expression of broiler chicken. A total of 480 day-old male broiler chickens were fed with 4 experimental diets for 6 wk. Experimental diets included corn-soybean meal diet (CON); corn-soybean meal diet + MOS prebiotic [0.2%, ActiveMOS; Biorigin, Brazile]; corn-FSBM diet [soybean meal (SBM) was totally replaced by FSBM]; and corn-FSBM + MOS prebiotic (MIX). Replacing dietary SBM with FSBM with or without MOS improved body weight gain and feed efficiency for the total grow-out period. However, the addition of MOS to the FSBM diet exhibited a greater body weight gain than other experimental diets. Villus height and villus height to crypt depth of the duodenum and jejunum were increased by feeding FSBM, MOS, and MIX diets. The ileal crude protein and energy digestibilities, as well as the activities of intestinal amylase and protease, and pancreatic protease, were improved by replacing SBM with FSBM, with or without MOS. The concentration of plasma 3-methylhistidine was reduced by FSBM and MOS, and synergistically by their combination. The MOS and FSBM diets upregulated the hepatic IGF-1 gene expression. However, there was an evident synergistic effect of FSBM supplemented with MOS in the upregulation of the hepatic IGF-1 gene expression. The outcomes of the current study indicate the FSBM and MOS had the potential to improve growth performance, hepatic IGF-1 expression, and intestinal morphology of broilers. Overall, the fermented products could be considered as functional feed that exhibits probiotic effects and the synergistic effects of prebiotics added to the fermented feeds may further improve the growth performance and gut health and functionality in broiler chicken.

ABSTRACTThe aim of this study was to investigate the effects of the inclusion levels of different types of rapeseed meal (RSM) on performance, organ weight, and serum biochemical parameters in Cherry Valley ducks in the starter period and grower-finisher period. In Exp. 1, a total of 750 seven-day-old male ducklings were divided into 5 dietary treatments with 6 replicate pens of 25 birds per pen. The starter diets with the inclusion of 0, 5, 10, 15, or 20% of double-low RSM contained 0, 1.37, 2.15, 3.46, or 5.31 µmol glucosinolates (GLS)/g in the finished feed (from day 7 to 21). In Exp. 2, a total of 900 fifteen-day-old male ducklings were divided into 6 dietary treatments with 6 replicate pens of 25 birds per pen. The grower-finisher diets with the inclusion of 0, 5, 10, 15, 20, or 25% of Indian RSM contained 0, 7.67, 15.34, 24.66, 31.21, or 38.44 µmol GLS/g in the finished feed (from day 15 to 42). For ducklings in the starter period (Exp. 1), body weight gain and feed intake decreased linearly as the dietary double-low RSM inclusion level increased at day 7 to 14, while growth rate was not influenced by dietary double-low RSM inclusion levels at day 15 to 21 and day 7 to 21. For ducks in the grower-finisher period (Exp. 2), growth performance decreased linearly as the dietary RSM inclusion level increased from 5 to 20%. In addition, dietary RSM inclusion levels induced liver enlargement in ducklings at day 21 (5 to 20% double-low RSM with 1.37 to 5.31 µmol/g GLS) and thyroid enlargement accompanied by increased serum AST and ALP activities in ducks at day 42 (5 to 15% Indian RSM with 7.67 to 23.66 µmol/g GLS). Therefore, our results indicated that the upper limit of using RSM sources in feed formulation should consider the anti-nutritional factor of GLS content at different stages of duck growth.

ABSTRACTThe effects of betaine supplementation on growth performance, blood components, nutrient digestibility, excreta noxious gas emission, and meat quality of broiler chickens were examined using different dietary crude protein (CP) and methionine (Met) levels. A total of 768 Ross 308 broiler chickens were allotted to four treatments, with 12 replications of each treatment conducted over 6 wk. Treatments were factorially designed, with 2 levels of CP [Starter: CP 21% (low Met) and 23% (high Met); Finisher: CP 18% (low Met) and 20% (high Met)] and 2 levels of betaine supplementation (0 and 0.12%). Body weight gain and feed conversion improved significantly as dietary levels of protein increased (P < 0.05), but the results for betaine supplementation differed. The concentrations of serum total protein, albumin, and glutathione peroxidase (GPx) were elevated by either the supplementary betaine or the CP (P < 0.05). In addition, serum albumin concentration significantly increased in groups fed low CP amounts and betaine 0.12% compared with groups fed low CP only (P < 0.05). Total tract digestibility of nitrogen in broilers fed high CP amounts or 0.12% betaine, was observed to be greater than that in groups fed low CP amounts or no betaine treatment (P < 0.05). Supplemental betaine affected excreta ammonia gas emission, and hydrogen sulfide concentrations decreased significantly in low CP-fed groups (P < 0.05). Breast meat quality and relative organ weights were not influenced by CP levels or dietary betaine supplementation. These results suggest that betaine does not increase productivity, but may affect serum total protein, albumin, GPx, excreta ammonia emission, and nitrogen digestibility in broiler chickens. In addition, betaine supplementation is more effective in increasing serum albumin concentration when it was added in low CP (low Met) diets.

ABSTRACTThe objective of this study was to investigate the effect of encapsulated essential oils and organic acids (EOA) on the growth performance, egg quality, intestinal morphology and functions, and microbial count of laying hens from week 21 to 30. A total of five hundred and four 21-wk-old layers were randomly allotted into 4 groups consisting of 7 replicates with 18 birds per replicate. The birds were fed a basic diet (CON) or diets with EOA at 150 mg/kg, 300 mg/kg, and 450 mg/kg in the other 3 groups, respectively. Compared to the CON group, the addition of 150 mg/kg EOA significantly increased laying rate (P < 0.05) of hens from week 21 to 25. A linear increasing (linear, P < 0.01) in ileal villus height of laying hens fed EOA from 150 to 300 mg/kg was observed at week 30. At week 25, the supplementation of 300 mg/kg EOA significantly increased (P < 0.05) mRNA relative expression of aminopeptidase, sodium-glucose cotransporter 1, and Na+-independent neutral amino acid transporter in duodenum and glucose transporter 2 in jejunum of laying hens compared to the CON groups. Meanwhile, the relative expression of glucose transporter 2 mRNA in the jejunum was upregulated with increasing concentration of EOA in diets (linear, P < 0.05). Hens in EOA 300 group had higher mRNA relative expression of mucin-2 in ileum (P < 0.05) than hens in CON group. Additionally, the secretory immunoglobulin in ileum A were linear decreased (linear, P < 0.01) with the increasing supplement of EOA. Dietary supplementation with EOA tended to increase (P = 0.083) the counts of Bifidobacterium in cecal digesta at week 25 and 30. In conclusion, dietary with EOA may maintain intestinal tract morphology and promote digestive and absorptive capacities and barrier function, especially at 300 mg/kg. This study provided evidence of using EOA as a potential feed additive for laying hens.

ABSTRACTWe evaluated the combination of immunomagnetic separation (IMS), multiple displacement amplification (MDA), and real-time PCR to detect Salmonella from poultry environmental samples. The limits of detection (LODs) of IMS-MDA real-time PCR with different culture enrichment hours (0, 4, 6, and 8 h) were determined in artificially inoculated litter samples from a specific pathogen-free (SPF) poultry farm. In addition, Salmonella detection rate of IMS-MDA real-time PCR with 8-h culture enrichment was compared with that of conventional real-time PCR and culture-based detection by analyzing 174 poultry environmental samples (boot swabs, drag swabs, and litter), and the levels of Salmonella in the samples were quantified using the most probably number method. The LODs of IMS-MDA real-time PCR with 0, 4 to 6, and 8-h enrichment were 10, 1, and 0.1 CFU/g, respectively. Salmonella was detected in 25 of the 174 environmental samples (14.4%) by IMS-MDA real-time PCR, compared with 24 (13.8%) by conventional real-time PCR and 19 (10.9%) by culturing. Cohen's kappa index indicated strong concordance (0.79) between IMS-MDA real-time PCR and culture detection. We demonstrated the potential of the IMS-MDA real-time PCR assay as a faster and more sensitive alternative to culture-based Salmonella detection from poultry environmental samples.

ABSTRACTThis study was conducted to evaluate the effects of iron glycine chelate (Fe-Gly) on egg quality of laying hens. A total of 810 laying hens (HyLine Variety White, 26 wk old) were randomly assigned to 6 groups, and each group consisting of 135 hens (5 replicates of 27 hens each). Hens in the control group received a diet supplemented with 60 mg Fe/kg as FeSO4, whereas hens in the other 5 groups received diets supplemented with 0, 20, 40, 60, and 80 mg Fe/kg from Fe-Gly, respectively. The study showed that dietary Fe-Gly treatments influenced (P < 0.05) the internal egg quality (egg weight, Haugh unit, albumen height), compared with the control group. However, dietary Fe-Gly supplementation showed few effects on the ultrastructure of eggshell in this study. The group of 60 mg Fe/kg as Fe-Gly was promoted (P < 0.05) in succinate dehydrogenase levels of liver and spleen compared with the 0 mg Fe-Gly/kg group, whereas the control (Fe/kg as FeSO4) group has no differences compared with the 0 mg Fe-Gly/kg group. The concentrations of Fe in the eggshell, yolk, and albumen were increased with increasing concentrations of Fe-Gly, where Fe-Gly (60, 80 mg Fe/kg) had higher (P < 0.01) Fe concentration than the control in yolk and albumen. The Fe-Gly groups (60, 80 mg Fe/kg) were influenced (P < 0.05) in transferrin, divalent mental transport 1, and ferroportin 1, compared with the control (FeSO4). In conclusion, Fe-Gly (60 mg Fe/kg) improved egg quality and egg iron enrichment. In general, there were no significant differences between Fe-Gly (40) and the control group in albumen height, Haugh unit, Fe concentration in eggshell and yolk. It revealed that FeSO4 could be substituted by a lower concentration of Fe-Gly and Fe-Gly may be superior to FeSO4 for egg quality in laying hens.

ABSTRACTPrevious work showed that peptides from duck eggs incubated for 15 D presented high total antioxidant activities. Here, this work explore the antioxidant activities of different segments, ZT1 (≤3 KD), ZT2 (≤10 KD), and ZT3 (≤30 KD), derived from duck embryo peptides and their protective effects against H2O2-induced oxidative damage in HepG2 cells. Peptides present no cytotoxicity to HepG2 cells. Moreover, ZT1 exhibits a higher ability to scavenge several radicals as well as stronger inhibition of H2O2-induced oxidative stress than ZT2 and ZT3. The activities of catalase and glutathione peroxidase as well as total superoxide dismutase increase in a concentration-dependent manner. Peptides are isolated from ZT1 and then subjected to LC-MS/MS to identify their sequences, followed by functional annotation, bioinformatics prediction, and hot-spot motif recognition. As a result, 413 potential functional peptides are identified, with some compounds exhibiting more than 1 function. This work will help for exploring bioactive substances in duck embryo eggs and enhance the utilization value of duck or other poultry eggs.

This study investigated the effect of dietary VA supplementation on maternal and its offspring in terms of the early growth performance, antioxidant index, and tissue VA content of the goslings. Yangzhou geese aged 180 D were selected and randomly distributed into 5 experimental groups with 15 female geese and 3 male geese in each group. The geese were fed a basal diet supplemented with 0, 4,000, 8,000, 12,000, or 16,000 IU/kg VA. Eggs were collected from each group starting at 300 D. After hatching, 96 goslings were selected from each maternal group and randomly distributed into 2 experimental groups with factorial arrangement (6 replicates × 8 geese), including 2 levels of VA supplementations, 0 and 9,000 IU/kg. The results are as follows: (1) Different levels of maternal VA supplementation significantly affected the BW and weight gain of 7-day-old offspring (P < 0.05). The weight gain of offspring administered 9,000 IU/kg VA was significantly higher than that of offspring administered the basal diet (P < 0.05). (2) Maternal VA levels significantly affected the T3, T4, and insulin levels of the offspring (P < 0.05). (3) The GSH-PX, SOD, T-AOC, CAT, and tissue VA content of the offspring were significantly higher and MDA was significantly lower in the 9,000 IU/kg VA group than in the no VA group (P < 0.05). (4) Maternal VA levels had a significant effect on offspring GSH, GSH-PX, SOD, MDA, T-AOC, and CAT (P < 0.05). Maternal and offspring VA supplementation interact with the weight gain, tissue VA content, GSH, GSH-PX, SOD, MDA, and CAT of goslings (P < 0.05). Maternal supplementation with 12,000 IU/kg VA and offspring supplementation with 9,000 IU/kg VA was conducive to gosling growth.

Salmonella and Campylobacter are leading human foodborne pathogens commonly associated with poultry and poultry products, and several methods to control these pathogens have been applied to poultry production. This study was conducted to evaluate the effect of CALSPORIN, (CSP), a direct-fed microbial (DFM), and yeast cell wall (Saccharomyces cervisiae, IMW50, a mannanoligosaccharide (MOS)-based prebiotic, on performance, levels of Salmonella and Campylobacter in the feces, and intestinal histomorphometry in turkey poults. A 21-day battery cage study was conducted using 4 dietary treatments, including: an unsupplemented basal diet (corn and soybean-based) as negative control (NC); basal diet supplemented with 0.05% DFM; basal diet supplemented with 0.05% MOS; and basal diet supplemented with 0.05% mixture of DFM and MOS at equal proportions. Female Large White turkey poults (n = 336) were randomly distributed in 6 electrically-heated battery cages with 4 treatments and 12 replicates per treatment (7 poults per replicate pen). The first 16 pens were not inoculated with bacteria, while poults in pens 17 to 32 were orally challenged at day 7 with 105 CFU Salmonella Heidelberg and the poults in pens 33 to 48 were orally challenged at day 7 with 105 CFU Campylobacter jejuni. Feed consumption, body weight, and feed conversion ratio were measured weekly and at the end of the experiment. At day 21, fresh fecal samples from each pen were collected for Salmonella and Campylobacter enumeration and ileal tissue samples were collected from 1 bird per pen for histomorphology examination. DFM and MOS supplementation was accompanied with reduced levels of Salmonella shed by the treated birds compared to the control group, and with increased body weight (P ≤ 0.05). The surface area of villi increased in the MOS-supplemented group compared to the control group (P ≤ 0.05). There was a significant difference in V:C ratio between supplemented groups and control group (P ≤ 0.05). Based on these results, there is potential for CALSPORIN and IMW50 to reduce Salmonella shedding in feces, enhance ileal mucosal health, and improve growth performance of turkey poults.

ABSTRACTPoultry meats can become contaminated with pathogenic bacteria through digesta leakage during processing. Reducing the bacteria load in digesta of market-aged broilers prior to processing reduces the incidence of fecal contamination at the processing plant. A lysozyme product was incorporated in a maltodextrin-based feed offered during the pre-shipping feed withdrawal period to reduce bacteria in ileal contents of market-aged broilers. Twenty 36-day-old broilers were randomly allocated to each of 16 pens. For a 9 h period each pen was randomly assigned to one of the following treatments: no feed, maltodextrin-based feed with a lysozyme product (Inovapure) added at 0, 10, or 20 g per kg of feed. Feed consumption was determined and a minimum of 3 birds were randomly selected from each pen and euthanized. The ileal contents were removed and weighed. Samples were analyzed for Clostridium perfringens, aerobic bacteria, Enterobacteriaceae, E. coli, and coliform numbers using standard culturing techniques and next generation sequencing was performed to determine population shifts. Bacteria counts were transformed to log10 colony forming units (cfu) and analyzed as a completely randomized design. The data from next generation sequencing was analyzed as a 3 × 5 factorial design using Proc Mixed of SAS. Lysozyme did not affect feed consumption nor were the weight of ileal contents different for birds fed maltodextrin-based feeds compared to birds on traditional feed withdrawal. E. coli/coliforms and Enterobacteriaceae plates had no signs of bacterial growth. The number of Clostridium perfringens and aerobic bacteria in the ileal contents of market-aged broilers was not different between treatments using the traditional culturing techniques. Next generation sequencing was a useful alternative to traditional culture techniques as results revealed that bacilli were reduced and clostridia increased for the 20 g lysozyme treatment. Addition of lysozyme to a maltodextrin based feed did not change overall numbers of bacteria but was effective in altering the participants in the bacteria community in ileal contents of market-aged broilers.

ABSTRACTThe purpose of this study was to establish optimal conditions for microwave-assisted phosphorylation modification of egg white. Response surface methodology was used to model and optimize the degree of phosphorylation, solubility, foaming ability, and foaming stability of egg white powder. The concentration of sodium tripolyphosphate, microwave power, and microwave time were selected as the main processing conditions in the phosphorylation modification of egg white protein. The following 3 conditions for optimal phosphorylation modification of egg white are the concentration of sodium tripolyphosphate of 33.84 g/L, microwave power of 419.38 W, and microwave time 90 s for maximum functional properties (solubility, foaming ability and foaming stability) and the concentration of sodium tripolyphosphate of 32.97 g/L, microwave power of 429.29 W and microwave time of 90 s for maximum foaming properties (foaming ability and foaming stability), respectively. We consequently succeeded in phosphorylation modification with microwave assistance and confirmed the various desirable properties of optimal phosphorylation modification.

Probiotics are considered the preferred alternatives to antibiotics for growth promotion and disease prevention. Previous studies have confirmed that Diutina rugosa SD-17 has the potential as a probiotic. We evaluated the probiotic effect of D. rugosa SD-17 on 360 one-day-old Hy-line brown chickens that were divided into 2 groups, and each group contained 6 replicate pens with 30 birds per pen. The chickens were fed with basal diet supplemented with or without D. rugosa SD-17, and the effects of D. rugosa SD-17 on growth performance, intestine morphology, and immune status were assessed. Body weight was significantly improved from week 3 to 6 (P < 0.05), and the feed conversion ratio was significantly improved in weeks 1 and 2 (P < 0.001). The length of the duodenum was lengthened significantly in week 3 (P < 0.05), and supplementation of D. rugosa SD-17 significantly increased villus height and villus height to crypt depth ratio in the ileum in week 3 (P < 0.05). Expressions of tight-junction-related genes of zonula occludens-2 and occludin in the ileum were significantly increased (P < 0.05). The proliferation capacity of blood lymphocytes stimulated by concanavalin A was significantly enhanced (P < 0.05), and the proportion of helper T (Th) cells increased significantly (P < 0.05). Expressions of Th1 cell markers IL-2 and interferon (IFN)-γ and immune-related genes of IL-1β, transforming growth factor-β, and IFN-γ in ileum were significantly increased (P < 0.05). These results indicated that D. rugosa SD-17 improved the growth and regulated immunity of chickens, and could be optimized for use as a feed additive for livestock and poultry.

The research studied the effects of l-methionine (l-Met) on growth performance, carcass quality, feather traits, and small intestinal morphology of Pekin ducks compared with conventional dl-methionine (dl-Met). A total of 1080, 1-day-old male Pekin ducks were randomly allotted to 9 groups with 6 replicate pens of 20 birds each. During the starter phase (1 to 14 d), ducks were fed a basal diet (Met, 0.30%) or that supplemented with dl-Met or l-Met at 0.05, 0.10, 0.15, or 0.20% of feed. During the grower phase (15 to 35 d), ducks were fed a basal diet (Met, 0.24%) or that supplemented with dl-Met or l-Met at 0.04, 0.08, 0.12, or 0.16% of feed. Compared with ducks fed the basal diet, supplementation with either dl-Met or l-Met increased the body weight (BW) of ducks at days 14 and 35, increased average daily gain (ADG) and average daily feed intake (ADFI), decreased F:G at the starter phase, and increased ADG over the whole 35-d period (P < 0.05). The efficacy of l-Met compared to dl-Met was 140.1% for 14-d BW, 137.6% for ADG and 121.0% for F:G for days 1 to 14. Ducks fed diets supplemented with l-Met had greater proportion of leg muscle, higher than in ducks provided with dl-Met (P < 0.05). The breast muscle proportion was enhanced with dl-Met rather than l-Met supplementation (P < 0.01). The back feathers score and fourth primary wing feather length were increased with dl-Met or l-Met supplementation (P < 0.01), and there was increased efficacy of l-Met relative to dl-Met for back feathers score (153.1%). Dietary dl-Met or l-Met supplementation increased villus height of ileal mucosa of ducks at days 14 and 35 (P < 0.01). Overall, dietary l-Met or dl-Met supplementation affected the growth performance of ducks during the starter phase, and improved the feather traits and small intestinal morphology. The efficacy of l-Met to dl-Met ranged from 120 to 140% for growth performance of young ducks (1 to 14 d) and was 153% for the feather traits of ducks (35 d).

ABSTRACTMuscle is one of the important economic traits in poultry production, and its production depends on the increased number of muscle fibers during the embryonic stage. Chicken GHR gene can transcribe in double directions, possessing not only GHR-S but also GHR-AS. The 2 kinds of transcripts are partially complementation in sequences and interact with each other. Until now, the roles and mechanisms of GHR-AS in myoblast differentiation was still unknown. In this study, we not only analyzed the GHR-AS expression patterns in myoblast differentiation phase but also clarified that GHR-AS promoted myoblast differentiation via GH-GHR-IGF1 signal pathway. Quantitative PCR analysis indicated that GHR-AS was increased during myoblast differentiation. Sub-cellular localization showed that GHR-AS and GHR-S were expressed at a higher level in the nucleus than that in the cytoplasm. The expression of MyoD and MyHC and the myoblast differentiation significantly increased after GHR-AS overexpression, while the distance between wounds decreased, suggesting that GHR-AS repressed myoblast migration and promoted differentiation. Additionally, the expression of GHR-AS, IGF1 and MyHC increased after GH protein treated, and the myoblast differentiation also increased. In conclusion, GHR-AS promoted myoblast differentiation by enhancing fusion and inhibiting migration possibly via GH-GHR-IGF1 signal pathway.

ABSTRACTMycoplasma gallisepticum (MG) infection produces a profound inflammatory response in the respiratory tract and evade birds’ immune recognition to establish a chronic infection. Previous reports documented that the flavonoid baicalin possess potent anti-inflammatory, and antioxidant activities. However, whether baicalin prevent immune dysfunction is largely unknown. In the present study, the preventive effects of baicalin were determined on oxidative stress generation and apoptosis in the spleen of chickens infected with MG. Histopathological examination showed abnormal morphological changes including cell hyperplasia, lymphocytes depletion, and the red and white pulp of spleen were not clearly visible in the model group. Oxidative stress-related parameters were significantly (P < 0.05) increased in the model group. However, baicalin treatment significantly (P < 0.05) ameliorated oxidative stress and partially alleviated the abnormal morphological changes in the chicken spleen compared to model group. Terminal deoxynucleotidyl transferase–mediated dUTP nick endlabeling assay results, mRNA, and protein expression levels of mitochondrial apoptosis-related genes showed that baicalin significantly attenuated apoptosis. Moreover, baicalin restored the mRNA expression of mitochondrial dynamics-related genes and maintain the balance between mitochondrial inner and outer membranes. Intriguingly, the protective effects of baicalin were associated with the upregulation of nuclear factor erythroid 2–related factor 2 (Nrf2)/Heme oxygenase-1 (HO-1) pathway and suppression of nuclear factor-kappa B (NF-κB) pathway in the spleen of chicken. In summary, these findings indicated that baicalin promoted mitochondrial dynamics imbalance and effectively prevents oxidative stress and apoptosis in the splenocytes of chickens infected with MG.

ABSTRACTThe utilization of male chickens for fattening constitutes a potential advantage of the dual-purpose concept. In addition to the use of commercial hybrids, producers could introduce alternative chicken genotypes or further develop local breeds. To gain more information about the genetic effect on growth performance, carcass characteristics, physicochemical meat traits, and sensory attributes, 60 cockerels belonging to Les Bleues (developed from the French breed Bresse Gauloise), Canarian (Spanish local breed), and Dominant Red Barred D459 (DRB D459; commercial dual-purpose hybrid) genotypes were reared under free-range conditions in a warm tropical climate and slaughtered at 15 wk of age. The major findings were as follows: (i) Les Bleues chickens exhibited the best growth rate and the body weight of 2.44 kg reached by this strain at 15 wk would be gained only after 18 to 19 wk with DRB D459 and it would take even 2 wk longer for Canarian breed, according to the growth modeling using the Morgan equation, although the body weights between the latter were statistical similar at 15 wk; (ii) Les Bleues strain had a good capability in terms of meat production performance, presenting carcasses with significantly heavier commercial cuts, and higher fleshiness than the other 2 genotypes; (iii) although significant differences among genotypes appeared in the physical characteristics of the breast meat, especially those concerning the skin and meat color and water-holding capacity, which was significantly reduced for Canarian chickens, no significant differences were detected in the chemical composition and fatty acid profile of the breast meat; (iv) trained panelists (n = 8) pointed out that leg meat of none of the genotypes is better in terms of global appreciation, but untrained consumers (n = 99) perceived that the Les Bleues leg meat was significantly more palatable than the DRB D459 leg meat.

ABSTRACTMethicillin-resistant Staphylococcus aureus (MRSA) are a major concern for public health, and broiler farms are a potential source of MRSA isolates. In this study, a total of 56 MRSA isolates from 15 broiler farms from 4 different counties in Germany were characterised phenotypically and genotypically. Spa types, dru types, SCCmec types, and virulence genes as well as resistance genes were determined by using a DNA microarray or specific PCR assays. In addition, PFGE profiles of isolates were used for analysis of their epidemiological relatedness. While half of the isolates belonged to spa type t011, the other half was of spa types t1430 and t034. On 3 farms, more than 1 spa type was found. The most common dru type was dt10a (n = 19), followed by dt11a (n = 17). Susceptibility testing of all isolates by broth microdilution revealed 21 different resistance phenotypes and a wide range of resistance genes was present among the isolates. Up to 10 different resistance phenotypes were found on individual farms. Resistance to tetracyclines (n = 53), MLSB antibiotics (n = 49), trimethoprim (n = 38), and elevated MICs of tiamulin (n = 29) were most commonly observed. Microarray analysis detected genes for leucocidin (lukF/S), haemolysin gamma (hlgA), and other haemolysines in all isolates. In all t1430 isolates, the egc cluster comprising of genes encoding enterotoxin G, I, M, N, O, U, and/or Y was found. The splitstree analysis based on microarray and PCR gene profiles revealed that all CC9/SCCmec IV/t1430/dt10a isolates clustered apart from the other isolates. These findings confirm that genotypic patterns were specific for clonal lineages rather than for the origin of isolates from individual farms.

ABSTRACTThe liver is an important organ that has pivotal functions in the synthesis of several vital proteins, the metabolism of various biologically useful materials, the detoxification of toxic substances, and immune defense. Most liver functions are not mature at a young age and many changes happen during postnatal liver development, which lead to differential functions of the liver at different developmental stages. However, the transcriptome details of what changes occur in the liver after birth and the molecular mechanisms for the regulation of the developmental process are not clearly known in chickens. Here, we used RNA-sequencing to analyze the transcriptome of chicken liver from the prenatal (at an embryonic day of 13) to the postnatal stages (at 5 wk and 42 wk of age). A total of approximately 161.17 Gb of raw data were obtained, with 4,127 putative and 539 differentially expressed lncRNAs, and with 13,949 putative and 6,370 differentially expressed mRNAs. Coexpression of lncRNAs-mRNAs in hepatic transcriptome analysis showed that the liver plays important roles in providing energy for organisms through the mitochondrial respiratory chain in chickens, meanwhile, acting as a crucial part of antioxidant stress. The developmental transcriptome date revealed that antioxidant defenses are likely to act on chicken embryo development and that significant functional changes during postnatal liver development are associated with the liver maturation of chickens. These results provide a timeline for the functional transcriptome transition from the prenatal to adult stages in chickens and will be helpful to reveal the underlying molecular mechanisms of liver development.

ABSTRACTThe inhibitory leukocyte immuno-globulin-like receptors (LILRBs) play an important role in innate immunity. Currently, no data exist regarding the role of LILRB4 and LILRB5 in the activation of immune signaling pathways in mammalian and avian species. Here, we report for the first time, the cloning and structural and functional analyses of chicken LILRB4–5 genes identified from 2 genetically disparate chicken lines. Comparison of LILRB4–5 amino acid sequences from lines 6.3 and 7.2 with those of mammalian proteins revealed 17 to 62% and 19 to 29% similarity, respectively. Phylogenetic analysis indicated that the chicken LILRB4–5 genes were closely associated with those of other species. LILRB4–5 could be subdivided into 2 groups having distinct immunoreceptor tyrosine-based inhibitory motifs, which bind to Src homology 2-containing tyrosine phosphatase 2 (SHP-2). Importantly, LILRB4–5 also upregulated the major histocompatibility complex (MHC) class I and β2-microglobulin gene expression as well as the expression of transporter associated with antigen processing 1–2, which play an important role in MHC class I activation. Our results indicate that LILRB4–5 are transcriptional regulators of the MHC class I pathway components and regulate innate immune responses. Furthermore, LILRB4–5 could activate the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway genes in macrophages and induce the expression of chemokines and T helper (Th)1, Th2, and Th17 cytokines. Our data suggest that LILRB4–5 are innate immune receptors associated with SHP-2, MHC class I, and β2-microglobulin. Additionally, they activate the JAK/STAT signaling pathway and control the expression of cytokines in macrophages.

ABSTRACTThe objective of this study was to assess the effect of dietary yeast products on broiler chickens challenged with salmonella lipopolysaccharide (LPS). The chicks were divided into 8 treatments with 6 replicates and 9 birds per replicate. The treatments consisted of a positive control (PC) [without supplementation and not challenged]; negative control (NC) [without supplementation but challenged]; whole yeast and challenged; yeast cell wall and challenged; yeast glucan and challenged; yeast mannan and challenged; zinc bacitracin and challenged; and Salinomycin and challenged. Whole yeast or Yeast cell wall was included at 2.0 g/kg diet. Yeast glucan or mannan was added at 0.20 g/kg diet. Zinc bacitracin (ZNB) and Salinomycin (SAL) was included at 50 and 60 ppm, respectively. Dietary treatments had no effect (P > 0.05) on feed intake (FI) at day 10. Supplementation with yeast and its derivatives improved (P < 0.05) body weight gain (BWG) and feed conversion ratio (FCR) on day 10. On days 24 and 35, LPS challenge declined FI, BWG, FCR, and flock uniformity (day 28) in the NC group compared to the PC group. Yeast products and antibiotics improved (P < 0.05) FI, BWG, FCR, and flock uniformity in LPS-challenged birds. On day 24, spleen weight increased while bursa weight decreased in the NC group relative to the PC group; this effect was reversed (P < 0.05) by feeding all yeasts and antibiotics. On day 24, application of all the dietary treatments ameliorated the changes observed in white blood cell, lymphocyte and monocyte counts as well as albumin and immunoglobulin G of NC birds. On day 35, all yeasts additives, ZNB and SAL improved (P < 0.05) the meat yield of broilers challenged with LPS. In conclusion, supplementation of diets with yeast and its derivatives can ameliorate the negative effects of salmonella LPS challenge on broiler chicks, thus improving the performance, flock uniformity, and meat yield.

ABSTRACTWork was done to modify a limestone solubility assay to improve predictions of in vivo apparent ileal digestibility of Ca (AID Ca) in broilers and impacts on AID P. Limestones (LIME) were obtained from 3 commercial sources. LIME-1 (0.633 mm mean diameter, GMD); LIME-2 (ground sub-sample of LIME-1, GMD = 0.063 mm); LIME-3 (GMD = 0.326 mm), and LIME-4 (GMD = 0.831 mm). Solubility was determined at 5, 15, and 30 min of incubation using either a 0.2 N HCl (S1) or a pH 3 HCl (pH = 0.26) solution buffered with 3 M glycine (S2) to mimic gizzard and proventriculus pH. An AID trial was conducted with 320 Ross 708 male broilers. Treatments (Trt) were no added LIME, or added LIME-1, 2, 3, and 4 to achieve 0.67% Ca, to a basal diet (no added inorganic P, 0.07% Ca) with or without 1,000 U phytase/kg (36 h, 23 to 24 D of age, n = 8, 4 birds/n). Distal ileal digesta was collected from all birds and pooled by pen. Irrespective of interaction, LIME solubilized quicker and more completely with S1 vs. S2 at all time points (P < 0.05). LIME-2 solubilized the quickest, while LIME-3 had the lowest solubility through all incubation times (P < 0.05). The AID Ca was 66.30, 47.46, 19.93, and 66.33% for LIME-1, 2, 3, and 4, respectively (0 U/kg, P < 0.05). Phytase inclusion increased AID Ca by 15% on average (P < 0.05). The AID P dig was highest in no LIME added diet (74.91%) and adding LIME reduced (P < 0.05) AID P to 23.14, 12.78, 65.47, and 37.40%, for LIME-1, 2, 3, and 4, respectively in the absence of phytase. Regression showed that GMD, 15- and 30-min solubility were critical for AID Ca (R2 between 0.978 and 0.988). In conclusion, the solubility dynamics including speed and extend of solubilization, rather than a single timepoint, yield better predictions for in vivo Ca digestibility of LIME.

ABSTRACTThis study was performed to investigate the hypothesis that supplementation of processed lignocellulose (PL) in the diets of broilers has a positive effect on growing performance, pH value of gizzard, hepatic enzyme activity, immunologic indicators, histomorphological character of small intestine, and cecal microflora populations. A total of 720 one-day-old Ross 308 broiler chicks were allotted to 4 treatment groups and fed maize−soybean meal based diets. The basal diet was supplemented with PL with an amount of 0 kg (control), 0.5 kg, 1 kg, and 2 kg per ton feed. Growing performance parameters, were determined weekly until 35 D of age. Blood samples for enzyme activities and immunoglobulins, jejunum and cecum samples for histomorphological characters for villus growth, and microbial population were collected from 12 broilers from each group. At 35 D of age, body weight of broilers supplemented with 1 kg of PL was found to be the highest with a value of 2305.0 g, when compared to the broilers supplemented with control, 0,5 and 2 kg of PL groups (2154.0, 2201.0, and 2141.7 g, respectively, P = 0.001). An increased activity of aspartate amino transferase (AST) was observed in the control and 1 kg PL supplementation groups (633.6 and 597.4 IU/L, respectively), whereas alkaline phosphatase (ALP) activity was the highest in the control group (5404 IU/L, P < 0.05). Broilers in the control group had the lowest level of IgY and IgA (122.2 and 25.8 mg/dL, respectively, P < 0.05). Villus height increased by 22.0%, 40.7%, and 34.8% in 0.5, 1, and 2 kg PL supplementation groups, respectively, when compared to the control (P < 0.001). The processed lignocellulose supplemented as 1 kg of PL decreased the average count of Staphylococcaceae, E. coli, and Enterobacteriaceae, whereas it increased the population of Lactobacillus spp. in the cecum (P < 0.05). These data indicate that the supplementation of processed lignocellulose had positive effects for performance via changes in hepatic enzyme activities, immunoglobulin levels, villus growth in jejunum, and microflora in cecum.

ABSTRACTSalmonella enteritidis (S. enteritidis) infection has been recognized as one of the most common bacterial causes of human gastroenteritis worldwide and is closely associated with eggs. Slightly acidic electrolyzed water (SAEW) is an emerging environmentally friendly technology for disinfecting eggshell surfaces to remove dirt and pathogenic microorganisms. However, the efficiency of SAEW could be affected by the presence of manure. UV-based advanced oxidation processes have been studied to improve the microorganism's inactivation effect of disinfection. Therefore, in this study, the synergistic bactericidal efficacy of SAEW and UV-C light (ultraviolet lamp, λ = 254 nm) for inactivation of S. enteritidis on artificially inoculated eggshells with or without manure was evaluated, and the bactericidal efficacy of different combination treatments of SAEW and UV-C light was compared. Without manure interference, complete inactivation (reduction of 6.54 log10 CFU/g) of S. enteritidis on the surface of eggshells was achieved following a 4-min treatment with SAEW+UV at an available chlorine concentration (ACC) of 20 mg/L. In the presence of manure, a 3.02 log reduction was achieved following a 4-min treatment with SAEW+UV at an ACC of 30 mg/L. Simultaneous treatment with SAEW and UV light exhibits higher bactericidal activity for eggshells than other combination process methods with UV and SAEW. The results suggest that the combined treatment of SAEW+UV is a novel method to enhance the microbial safety of eggshells.

ABSTRACTNecrotic enteritis (NE) is a pervasive enteric disease responsible for large scale economic losses within the global poultry industry. The etiologic agent of NE is Clostridium perfringens (CP), an opportunistic pathogen that utilizes numerous extracellular toxins and glycoside hydrolases (GH) as key virulence and nutrient acquisition factors. Notably, some GH, mucinases, degrade components of mucin in the gastrointestinal tract as an energy source. Targeting this mechanism may serve to reduce the incidence of disease associated with CP. Two experiments were completed that evaluated mucinase vaccine targets sourced from conserved peptide sequences of carbohydrate binding module 32 of CP mucinases. In experiment 1, 37 antigen peptides were synthetically generated and used to produce hyper-immune sera, which was then evaluated for ability to obstruct CP growth in vitro. Total CFU of CP were measured at 4, 6, and 8 h incubation to determine growth rate. Peptides 4, 5, 22, 24, and 30 were selected for further in vivo testing based on conservation or the ability to inhibit CP growth by over 50% at 6 and 8 h. In experiment 2, the aforementioned peptides were conjugated to an agonistic, CD40-targetting antibody and evaluated in vivo. Broilers were given an Eimeria maxima and CP in order to induce NE and assess vaccine efficacy. Treatments included a non-vaccinated non-inoculated control, non-vaccinated inoculated control (NVIC), vaccination with peptide 4, 5, 22, 24, or 30 (VP4-VP30), or a combination of all 5 peptides (MC). There was a significant increase (P < 0.05) in the percent change in BWG relative to NVIC for vaccination with peptide 22 and MC of 18.54 and 17.43%, respectively. MC vaccinated group had the lowest lesions with a mean score of 0.63 ± 0.18. These results suggest the MC combination was the most successful in alleviating overall performance losses associated with NE-infected broilers and encourage future testing of MC in the development of an NE vaccine.

ABSTRACTNutrition is a crucial factor for growth and bone development in broiler chickens. Adjustments in dietary ingredients might affect bone development and consequently locomotion related problems. This study was designed to evaluate effects of dietary organic minerals (ORM), fish oil (FISH), and hydrolyzed collagen (COL) on growth performance and tibia characteristics of broiler chickens. A total of three hundred eighty four 1-day-old Ross 308 male broiler chickens were used in a complete randomized block design with 4 diet groups and 8 replicates per diet group. In the ORM diet, the inorganic macro and trace minerals were replaced by their organic varieties. In the FISH diet, palm oil and soybean oil were partly replaced by FISH. In the COL diet, soybean meal was partly replaced by COL. Results showed that the ORM and COL diet groups reached a higher body weight (BW) at 42 D of age than the FISH diet group, whereas the control group was in between. The feed conversion ratio between day 1 and 42 was lower in the ORM and COL diet groups than in both other diet groups. On day 28, 35, and 42, gait score (GS), Varus Valgus deformity, tibia length (TL), thickness, femoral and metatarsal head thickness (THT), mineral content (TMC), mineral density (TMD), breaking strength (TBS), stiffness (TSF), and energy to fracture (TEF) were measured (n = 3/replicate). The ORM diet group had higher TL at day 42, higher THT at day 28, higher TMC at day 42, higher TMD at day 28, 35, and 42, higher TBS at day 42, higher TSF at day 35 and 42, and higher TEF at day 42 compared to the FISH diet group, with the COL and control diet groups in between. It can be concluded that replacing dietary inorganic macro and trace minerals by their organic varieties seems to stimulate tibia dimensions, strength, and mineral content of broiler chickens. On the contrary, FISH appears to negatively affect tibia characteristics.

ABSTRACTThis study aimed to investigate the effect of using breeder parents (434-days-old) and broiler chickens (37 D of age) from Ross 308 on meat quality parameters and carcass characteristics; sex and muscle type were also estimated. Carcass assessment involved hot carcass weight, carcass yield, and cuts (breast, legs, wings, back, and shoulder). A total of 120 birds were divided into 2 groups (60 birds from each stock), each stock contain equal number of sexes (30 males and 30 females), and further divided into 6 replicates, so that there were 5 birds in each replicate. The birds were fed ad libitum. A sample of 30 birds (male, n = 15 and female, n = 15) from each group was slaughtered for assessing carcass and physical characteristics. Sensory analysis was carried out on each group after boiling or roasting the bird. Live weight, carcass weight and yield, breast weight, legs, wings, and back weights and yield were higher (P < 0.001) for breeder parents when compared to broilers, with the exception of breast percentage. Moreover, better carcass characteristics were observed in males than in females. Parent stock had better water-holding capacity and myofibrillar fragmentation whereas broilers had more tender meat than breeders. Moreover, cooking loss and other sensory characters were not significant between the two groups; however, females had more tender pectoral muscles and more myofibrillar fragmentation than males. We concluded that parent breeders had better carcass characteristics than broiler chickens. The broiler chickens of Ross 308 and female birds had better meat quality than parent breeders.

ABSTRACTThis study was conducted to determine the effects of essential oils and organic acids (EOA) on Salmonella Enteritidis (S. Enteritidis) challenged chickens. One-day-old specific pathogen-free (SPF) chicks (250) were randomly assigned to 5 groups, with 50 birds in each group. The treatment groups were as follows: 1) basal diet, negative control group (NC); 2) basal diet + S. Enteritidis, positive control group (PC); 3) PC + 4,000 g/t of enrofloxacin (5%), antibiotic group (ENR); 4) PC + 800 g/t of EOA1, thymol-benzoic acid group (TBA); and 5) PC + 800 g/t of EOA2, cinnamylaldehyde-caproic acid group (CCA). At 7 D of age, each bird, except those in NC, was orally gavaged with 0.4 mL of a suspension of 4.4 × 109 cfu S. Enteritidis/mL. Results revealed that ENR reduced bacterial counts in the liver and spleen on days 3, 5, and 7 post-challenge more (P < 0.05) than any other treatments. However, bacterial counts in cecal contents among ENR, TBA, and CCA were similar at 5 and 7 D post-challenge but lower than those of PC. Additionally, the bacterial counts in liver, spleen, and cecum contents in TBA were lower (P < 0.05) than in PC at 3, 5, and 7 D post-challenge; the bacterial counts in spleen contents in TBA were lower (P < 0.05) than in CCA at 7 D post-challenge. Tumor necrosis factor-α contents in TBA and CCA were lower (P < 0.05) than those in PC. Also, the ratio of villus height to crypt depth in the ileum of CCA was higher (P < 0.05) than that of PC and ENR; however, there was no difference in the secretory IgA content of the jejunum among the groups. In conclusion, EOA had a bacteriostatic effect on S. Enteritidis, and the effect of the thymol-benzoic acid complex surpassed that of the cinnamaldehyde-caproic acid complex. Therefore, EOA may act as an effective antibiotic substitute for animals in the prevention and treatment of Salmonella.

ABSTRACTChromium propionate (Cr Prop) is approved by the U.S. Food and Drug Administration Center for Veterinary Medicine for supplementation to broiler diets up to 0.20 mg Cr/kg diet. A 49-D study was conducted to: 1) determine the safety of Cr Prop when supplemented at 2 and 10 times (×) the approved feeding level over the normal life span of broilers, and 2) determine the effects of supplementing Cr Prop on Cr concentrations of tissues consumed by humans. On day zero, 216 Ross 708 broilers were stratified by weight within sex and randomly assigned to treatments. Dietary treatments were 0 (control), 0.40, and 2.0 mg supplemental Cr/kg diet from Cr Prop. There were 6 replicate cages each of male and female broilers per treatment. At the end of the study blood was collected for determination of plasma biochemical measurements and tissue samples were collected for Cr analysis. Supplementing 0.40 mg Cr/kg diet (2×) did not adversely affect broiler performance, mortality, plasma biochemical measurements or Cr concentrations in breast muscle, skin with adhering fat, or liver. Chromium propionate supplemented at 2.0 mg Cr/kg (10×) did not affect Cr concentrations in breast muscle or skin with adhering fat, but increased (P < 0.05) liver Cr concentrations. Supplementing Cr Prop at 10× the approved feeding level decreased feed intake and gain in male but not female broilers from days 21 to 49. Results of this study support the safety of Cr Prop in broiler diets, and indicate that Cr Prop supplementation to broiler diets at 2 or 10× the approved feeding level does not present a human health concern.

ABSTRACTFeeding broiler breeders to satiety has negative consequences on their health and reproduction. Alternative feeding strategies during rearing can improve welfare, although their implications during lay are not well understood. The objective was to examine the effect of rearing feeding treatments on the reproductive performance and feeding behavior of broiler breeders under simulated commercial conditions. At 3 wk of age, 1,680 Ross 308 pullets were allocated to 24 pens under 1 of 4 isocaloric treatments: 1) daily control diet; 2) daily alternative diet (40% soybean hulls and 1 to 5% calcium propionate); 3) 4/3 control diet (4 on-feed days, 3 non-consecutive off-feed days per week); and 4) graduated control diet. Feeding frequency of the graduated treatment varied with age and finished on a daily basis. At 23 wk of age, group sizes were adjusted to 40 hens, and 5 mature Yield Plus Males roosters were introduced to each pen. Pens were under the same daily feeding management and same diet during lay. The performance of broiler breeders (growth rate, body weight uniformity, and reproductive performance) was determined until 64 wk of age. At the end of lay, feeding motivation was examined with a feed intake test and a compensatory feeding test. Data were analyzed using linear mixed regression models, with pen nested in the models and age as a repeated measure. The laying rate of hens reared on the graduated treatment decreased slower compared to control hens, resulting in a higher cumulative egg production (178.2 ± 3.8 eggs/hen) than control hens (165.2 ± 3.8 eggs/hen, P < 0.01) by 64 wk of age. Hens reared on non-daily feeding treatments laid lighter eggs with relatively heavier yolks and had higher feed intake at the end of lay than hens fed daily during rearing (P = 0.02). In conclusion, rearing feeding treatments impacted the growth rate and body weight uniformity during lay, feeding motivation at the end of lay, and the laying rate and hatchability depending on hens’ age.

ABSTRACTDuck hepatitis A virus (DHAV) is one of the pathogens that cause fatal duck viral hepatitis (DVH) in ducklings, which is an acute and contagious disease with a high mortality rate. Despite a continuing official duck vaccination program, DHAV infection remains a major threat to the duck industry. Considerable changes were observed in the epidemiology of DHAV-1/-3 in China over time. Therefore, comparing the pathogenicity of different DHAV serotypes can provide a theoretical basis for the diagnosis and prevention of DVH. In this study, we systematically investigated the effects of infection with DHAV-1/-3 field strains on clinical signs, gross lesions, histopathological changes, viral RNA detection, enzymatic systems, and metabolite concentrations. The results demonstrated that the major macroscopic and microscopic lesions in ducks infected with DHAV-1/-3 in the liver, brain, spleen, pancreas, and kidneys exhibited no significant differences. After 24 h of infection, DHAV quickly appeared in blood and major organs. Significant changes in clinical chemical markers together with histopathological lesions and viral RNA detection indicated that the liver is the major target organ for both viruses, resulting in impaired of liver integrity and function. In addition, we found that both viruses were able to invade both central and peripheral immune organs. Also lipase plasma activity was substantially affected by DHAV-1/-3, indicating that the integrity and function of the pancreas was compromised. However, there was no significant difference in pathogenicity between DHAV-1 and -3. The results of this study provide new insights into the pathogenesis of DHAV-1/3, two viruses that cause serious depression, metabolic disorders, and immunosuppression.

ABSTRACTBroiler breeding programs rely on crossbreeding. With genomic selection, widespread use of crossbred performance in breeding programs comes within reach. Commercial crossbreds, however, may have unknown pedigrees and their genomes may include DNA from 2 to 4 different breeds. Our aim was, for a broiler dataset with a limited number of sires having both purebred and crossbred offspring generated using natural mating, to rapidly derive parentage, assess the distribution of the sire contribution to the offspring generation, and to assess breed-of-origin of alleles in crossbreds. The dataset contained genotypes for 56,075 SNPs for 5,882 purebred and 10,943 3-way crossbred offspring generated by natural mating of 164 purebred sires to 1,016 purebred and 1,386 F1 crossbred hens. Using our algorithm FindParents, joint parentage derivation for the offspring and parent generations required only 1 m 29 s to retrieve parentage for 20,253 animals considering 4,504 possible parents. FindParents was similarly accurate as a maximum likelihood based method, apart from situations where settings of FindParents did not match the genotyping error rate in the data. Numbers of offspring per sire had a very skewed distribution, ranging from 1 to 270 crossbreds and 1 to 154 purebreds. Derivation of breed-of-origin of alleles relied on phasing all genotypes, including 8,205, 372, and 720 animals from the 3 pure lines involved, and allocating haplotypes in the crossbreds to purebred lines based on observed frequencies in the purebred lines. Breed-of-origin could be derived for 96.94% of the alleles of the 1,386 F1 crossbred hens and for 91.88% of the alleles of the 10,943 3-way crossbred offspring, of which 49.49% to the sire line. The achieved percentage of assignment to the sire line was sufficient to proceed with subsequent analyses requiring only the breed-of-origin of the paternal alleles to be known. Although required number of animals may be population dependent, to increase the total percentage of assigned alleles, it seems advisable to use at least approx. 1,000 genotyped purebred animals for each of the lines involved.

ABSTRACTFoot pad dermatitis (FPD) is a serious problem of the modern poultry industry, negatively affecting birds’ welfare and health status, walking and feeding activity, growth performance, carcass quality, and economic performance of meat production. The gut microbiome in poultry with FPD has not been previously investigated. Therefore, we compared the cecal microbiomes of 8 breeding ducks with FPD to 8 control ducks (breeders with apparently healthy feet) by pyrosequencing the bacterial 16S ribosomal RNA gene. The results showed a significant β-diversity (P < 0.05) of cecal microbiota presented between healthy and FPD-affected breeder ducks. The plasma endotoxins, interleukin 1β (IL-1β), IL-17, IL-6, IL-10, and tumor necrosis factor-α concentration, and the abundance of class Clostridia in FPD-affected ducks was markedly higher (P < 0.05), however, the abundance of genus Prevotella, Lactobacillus, Lachnospiraceae UCG-008, and the Firmicutes to Bacteroidetes ratio in FPD-affected ducks was significantly lower (P < 0.05) when compared to healthy ducks. These findings suggest when duck breeders are affected with FPD, ducks show an increased inflammatory response and a difference of structure and composition of the cecal microbiome.

ABSTRACTWe studied the changes in morphological, geometric, densitometric, and mechanical parameters of the femur and tibia during 56 D of rearing chickens with different growth rates. Ten femur and tibia were collected from fast-growing chickens (FG) and 2 types of medium-growing chickens (MGH and MGGP) immediately after hatching (0 D) and on 7, 14, 21, 35, 42, 49, and 56 D of life. The bone parameters of chickens across all genetic groups were found to be similar on 0 D, with exceptions of lower percentage contribution of bone weight (BW) in FG chickens (P < 0.05), lower total bone volume in MGGP chickens (P < 0.05), and lower maximum elastic strength in MGH chickens (P < 0.05). The bones developed in FG chickens were longer and wider; however, an increase in bone mineral density (BMD) between 42 and 49 D was not observed. The BMD value in FG chickens on 56 D was comparable to that in MGH chickens (P = 0.089) and significantly lower than that in MGGP chickens (P = 0.021). Mean relative wall thickness, despite longer and thicker bones in FG chickens, was comparable and often lower than that of MGH and MGGP chickens. In conclusion, the results showed that medium-growing chickens could be reared for up to 56 D without the risk of any growth impairment due to problems associated with deterioration of pelvic limb bone quality.

ABSTRACTPullorum disease caused by Salmonella Pullorum is one of the most important infectious diseases in the poultry industry worldwide, which leads to serious economic losses in many developing countries because of its high mortality rate in young chicks. The traditional slide agglutination test with low cost, fast reaction, and on-site detection has been widely used in the diagnosis of Pullorum disease. However, in practice, the test performance is with the disadvantages of false positive results and unstable detection results. In this paper, we developed self-made agglutination antigens prepared by local isolates in the poultry farm and compare the detection performance with commercial agglutination antigens (China Institute of Veterinary Drug Control) and Group D Salmonella ELISA kit (BioChek UK Ltd). The results of detecting 200 serum samples indicated that the consistency of commercial agglutination antigen detecting in 2 times was only 79.5%. Using the ELISA kit as the reference method, the commercial agglutination antigen detecting results of the Kappa test were only moderately consistent (0.58 ∼ 0.59). Meanwhile, positive and total coincidence rates of the self-made agglutination antigen test with more reliable repeat could reach 97.4 and 88%, respectively, and the result of Kappa test was highly consistent (0.75). The Receiver Operating Characteristic curve analysis clarified that the area under the receiver-operating-characteristic curve values of self-made and commercial agglutination antigen tests could reach 0.861 and 0.804, respectively. These results were coincident when detecting known positive serum from the infected chickens. It's worth mentioning that the visible positive reaction of self-made agglutination antigen test appeared faster and stronger than commercial antigen test. In conclusion, self-made Salmonella Pullorum agglutination antigen developed in this study was much better than commercial agglutination antigen and is expected to be a valuable tool in the diagnosis of the epidemiology of Salmonella Pullorum.

ABSTRACTA preovulatory surge (PS) of luteinizing hormone (LH) and progesterone triggers follicle ovulation, which is the first step of egg production and is orchestrated by the hypothalamo-pituitary-gonadal (HPG) axis. In the HPG axis, hypothalamic peptides, gonadotropin releasing hormone, and gonadotropin inhibitory hormone, control the production of follicle stimulating hormone and LH by the pituitary, which subsequently regulate ovarian production of estradiol and progesterone, respectively. The goal of this study was to characterize the HPG axis function of average egg producing hens by assessing plasma hormone profiles and hypothalamic, pituitary, and follicle gene expression outside and during the PS (n = 3 per group). Results were analyzed by a one-way ANOVA using the mixed models procedure of SAS. Plasma estradiol was not affected by the PS (P > 0.05), but plasma progesterone levels increased 8-fold during the PS when compared to basal progesterone levels (P < 0.05). HPG axis gene expression related to ovulation stimulation (e.g., GNRH, GNRHR, and LHB) was down-regulated during the PS; whereas gene expression related to follicle development (e.g., FSHB) was up-regulated during the PS. Additionally, in the hypothalamus and pituitary, estradiol receptor expression was up-regulated during the PS, whereas progesterone receptor expression was down-regulated during the PS. In the follicle cells, gene expression pertaining to progesterone (e.g., STAR), androgen (e.g., HSD17B1), and estradiol (e.g., CYP19A1) production was up-regulated during the PS. Prior to this study, the HPG axis had yet to be characterized during the PS in the turkey hen. This study showed that the PS significantly impacted gene expression in the hypothalamus, pituitary, and ovarian follicles. These results provide a foundation for further research into the regulation of ovulation and egg production in turkey hens.

ABSTRACTThe objective of this study was to estimate phenotypic and genetic parameters for clutch and broodiness (BR) traits in turkeys and their relationship with body weight and egg production. Data on dam line hens was available and included: body weight at 18 wk of age (BW18), body weight at lighting (BWL, 29 to 33 wk), age at first egg (AFE), egg number (EN), rate of lay (RL), clutch length (CL), maximum clutch length (MCL), pause length (PL), maximum PL (MPL) and BR. BR was defined as the average number of consecutive pause days between clutches that was higher than the average PL per hen. Heritability estimates for BW18 and BWL were 0.50 and 0.53, respectively. The heritability for egg production, clutch, and pause traits varied from low (MPL = 0.15; BR = 0.15) to moderate (AFE = 0.22; EN = 0.28; RL = 0.29; CL = 0.21; MCL = 0.27; PL = 0.25). Genetic correlations were negative between body weight traits and EN (rg (BW18, EN) = −0.27; rg(BWL, EN) = −0.33) and CL (rg(BW18, CL) = −0.40; rg(BWL, CL) = −0.33). BR was negatively genetically correlated with EN (rg(BR, EN) = −0.85) and CL (rg(BR, CL) = −0.30), and positively genetically correlated with PL (rg(BR, PL) = 0.93) and AFE (rg(BR, AFE) = 0.21). EN had a positive (0.73) and a negative (−0.84) genetic correlation with CL and PL, respectively. Overall, the results of this study confirmed the negative (unfavorable) correlations between egg production and body weight. Despite unfavorable genetic and phenotypic correlations between egg production traits and those relating to BR, the inclusion of BR in a selection program through incorporation of clutch length traits and pause length traits is feasible. Integration of either clutch length traits or pause length traits in a selection index is likely to increase egg number while decreasing broodiness.

ABSTRACTAvian infectious bronchitis virus (IBV), a coronavirus, causes infectious bronchitis leading to enormous economic loss in the poultry industry worldwide. Hypericin (HY) is an excellent compound that has been investigated in antiviral, antineoplastic, and antidepressant. To investigate the inhibition effect of HY on IBV infection in chicken embryo kidney (CEK) cells, 3 different experimental designs: pre-treatment of cells prior to IBV infection, direct treatment of IBV-infected cells, and pre-treatment of IBV prior to cell infection were used. Quantitative real-time PCR (qRT-PCR), immunofluorescence assay (IFA), flow cytometry, and fluorescence microscopy were performed and virus titer was determined by TCID50. The results revealed that HY had a good anti-IBV effect when HY directly treated the IBV-infected cells, and virus infectivity decreased in a dose-dependent manner. Furthermore, HY inhibited IBV-induced apoptosis in CEK cells, and significantly reduced the mRNA expression levels of Fas, FasL, JNK, Bax, Caspase 3, and Caspase 8, and significantly increased Bcl-2 mRNA expression level in CEK cells. In addition, HY treatment could decrease IBV-induced reactive oxygen species (ROS) generation in CEK cells. These results suggested that HY showed potential antiviral activities against IBV infection involving the inhibition of apoptosis and ROS generation in CEK cells.

ABSTRACTInfectious bronchitis (IB), caused by infectious bronchitis virus (IBV), account for severe economic losses in the poultry industry. The continuous emergence of a multitude of IBV variants poses many challenges for its diagnosis and control, and live attenuated vaccines, despite their routine use, still plays a significant role in driving IBV evolution, further complicating the epidemiological scenario. Unfortunately, the impact of different vaccination strategies on IB control, epidemiology, and diagnosis has rarely been investigated.This work presents the results of a large-scale diagnostic survey performed in Poland to study IBV molecular epidemiology and how vaccination may affect the viral circulation in the field. To this purpose, 589 samples were collected between May 2017 and January 2019, tested by reverse transcription-PCR for IBV and sequenced. Vaccine and field strains were discriminated based on genetic and anamnestic information.The most commonly detected lineages were 793B (79%) and variant 2 (17.4%), with sporadic detections of QX, Mass, and D274-like strains. Most of the detected strains had a vaccine origin: 46.3% matched one of the applied vaccines, while 36.5% were genetically related to vaccines not implemented in the respective protocol. Besides their practical value for the proper planning of vaccination protocols in Poland, these results suggest that only a fraction (17.2%) of the circulating strains are field ones, imposing a careful assessment of the actual IBV field menaces. Moreover, phenomena like vaccine spreading and persistence seem to occur commonly, stressing the need to further study the epidemiological consequences of the extensive use of live vaccines.

ABSTRACTEffects of light sources, photoperiods, and strains on growth performance, carcass characteristics, and health indices of broilers grown to heavy weights (>3 kg) were evaluated. The experimental design was a 4 × 2 × 2 factorial treatments consisting of 4 light sources [incandescent (ICD, standard), compact fluorescent light, neutral light emitting diode (Neutral-LED), and cool poultry specific LED (Cool-poultry specific (PS)-LED)], 2 photoperiods (regular/intermittent [2L:2D], and short [8L:16D]), and 2 strains (A, B). In each trial, chicks of 2 different strains from different commercial hatcheries were equally and randomly distributed into 16 environmentally controlled rooms at 1 D of age. Each room was randomly assigned one of 16 treatments from day 1 to 56 D of age. Feed and water were provided ad libitum. Birds were provided a 4 phase-feeding program (starter, grower, finisher, withdrawal). Birds and feed were weighed on 1, 14, 28, 42, and 56 D of age for growth performance. On day 56, a total of 20 (10 males and 10 females) birds from each room were processed to determine weights and yields. The BW, BW gain, live weight, and carcass weight of birds reared under PS-LED were higher (P < 0.05) in comparison with birds reared under ICD, but feed intake, feed conversion ratio, mortality, and carcass characteristics were not affected by treatments. Also, broilers subjected to the short/non-intermittent photoperiod had the lowest (P < 0.05) growth performance and carcass characteristics compared with values obtained for regular/intermittent photoperiods. In addition, strain was significant (P < 0.05) for most of the examined variables. Feed conversion, fat, tender, and yield were not affected by treatments. There was no effect of photoperiod, light sources, or their interactions on mortality. This study shows positive impacts on alternative light sources when compared to ICD along with regular/intermittent photoperiod in commercial poultry facilities rearing the 2 strains used in this study, thereby reducing energy costs and optimizing production efficiency without compromising the welfare of broilers grown to heavy weights.

ABSTRACTThe aim of this study was to investigate the effect of dietary resveratrol supplementation on innate immunity and inflammatory responses in the spleen of yellow-feather broilers under heat stress. A total of 288 yellow-feather broilers of 28-day-old were randomly assigned to 3 treatment groups with 6 replicates. A thermo-neutral group (TN) (24 ± 2°C) received a basal diet and another 2 heat-stressed groups (37 ± 2°C for 8 h/D and 24 ± 2°C for the remaining time) were fed the basal diet (HT) or basal diet with 500 mg/kg resveratrol (HT+Res) for 14 consecutive days. The results showed that heat stress decreased (P < 0.05) the growth index of thymus, spleen, and bursa of Fabricius, reduced (P < 0.05) the levels of complement C3 and C4 in serum. Heat stress also caused activation of inflammatory immune responses evidenced by increased (P < 0.05) the mRNA abundance of HSP (heat shock protein) 70, toll-like receptor (TLR)1, TLR4, TLR5, myeloid differentiation factor-88 (MyD88), nucleotide-binding oligomerization domain 1 (NOD1), Dectin-1, transforming growth factor-β-activated kinase 1 (TAK1), interleukin (IL)-1, IL-4, IL-6, and tumor necrosis factor (TNF)-α, but decreased the mRNA abundance of interferon (IFN)-γ, activated nuclear factor kappa B (NF-κB), mitogen-activated protein kinases (MAPK), and phosphoinositide-3 kinases-protein kinase B (PI3K/AKT) signaling pathways. Dietary supplementation with resveratrol improved (P < 0.05) the growth index of thymus, spleen and bursa Fabricius, and increased (P < 0.05) the serum level of complement C3 under heat stress. In addition, resveratrol reduced (P < 0.05) the mRNA abundance of HSP70, TLR4, TLR5, NOD1, Dectin-1, and TAK1, and inhibited the NF-κB, MAPK and PI3K/AKT signaling pathway via down-regulated the phosphorylation of p65, extracellular signal-regulated kinases 1/2, c-Jun N-terminal protein kinase and AKT, as well as decreased the inflammatory cytokines expression, including IL-1, IL-4, IL-6, and TNF-α in the spleen under heat stress. Collectively, dietary resveratrol could have beneficial effects to regulate innate immunity and inflammatory response, via inhibiting the activation of NF-κB, MAPK, and PI3K/AKT signaling pathways induced by heat stress in the spleen.

ABSTRACTContinuous sampling provides the most complete data set for behavioral research; however, it often requires a prohibitive investment of time and labor. The objectives of this study were to validate behavioral observation methods of young broiler chickens using 1) 7 scan sampling intervals (0.5, 1, 3, 5, 10, 15, and 30 min) and 2) an automated tracking software program (EthoVision XT 14) compared to continuous behavioral observation, considered the gold standard for behavior observation. Ten 19-day-old Ross 708 broiler cockerels were included in this study. All behavior was video recorded over an 8-h period, and data were collected using a continuous sampling methodology. The same video files were utilized for analysis for scan sampling and automated tracking software analysis. For both analyses, the following criteria were used to identify which method accurately reflected the true duration and frequency for each behavior, as determined by continuous observation: R2 ≥ 0.9, slope was not different from 1 (P > 0.05), and intercept was not different from 0 (P > 0.05). Active, eating, drinking, and maintenance behaviors were accurately estimated with 0.5-min scan sample intervals. Active, inactive, eating, and maintenance behaviors were accurately estimated with 1-min scan sample intervals. Inactive behavior was accurately estimated with 5-min scan sample intervals. The remainder of sampling intervals examined did not provide accurate estimates, and no scan sampling interval accurately estimated the number of behavior bouts. The automated tracking software was able to accurately detect true duration of inactive behavior but was unable to accurately detect activity. The results of this study suggest that high-frequency behaviors can be accurately observed with instantaneous scan sampling up to 1-min intervals. Automated tracking software can accurately identify inactivity in young broiler chickens, but further behavior identification will require refinement.

ABSTRACTLaying hens suffer from osteoporosis during their laying period, which causes bone fragility and susceptibility to fracture. This study evaluated the changes of mechanical properties of their bones during the laying period (from 18 to 77 wk) by using nano-indentation, atomic force microscope, X-Ray diffraction, and Raman spectroscopy. Results indicated that the crystallite sizes of bioapatite in femur decreased significantly from 34.45 to 29.26 nm during aging from 18 to 49 wk. Then, the value increased to 37.79 nm at 77 wk. Despite the abundance in bone (usually >50 wt.%), bioapatite mineral content showed no continuous enhancement during aging. The fibrils demonstrated more regular and organized structure during the laying period. Meanwhile the elastic moduli (E) and hardness (H) of femur increased from 10.84 to 18.39 GPa and 43.79 to 97.21 Vickers respectively during this period. The changes in mechanical properties are hence tightly related to the structure of bone (composed of both collagen and mineral), rather than directly related to the mineralogical properties of bone bioapatite. This study addressed the importance of the interaction between collagen and bioapatite mineral during the laying period of hens by microscopic, physicochemical, and mechanical analysis.

ABSTRACTThe poultry industry has recently undergone transitions into antibiotic free production, and viable antibiotic alternatives, such as probiotics, are necessary. Through in ovo probiotic inoculation, beneficial microflora development in the gastrointestinal tract may occur prior to hatch without negatively impacting chick performance. Therefore, the objective of the present study was to observe the impacts of the injection of probiotic bacteria individually or combined into fertile broiler hatching eggs on hatch and live performance characteristics. A total of 2,080 fertile broiler hatching eggs were obtained from a commercial source. On day 18 of incubation, 4 in ovo injected treatments were applied: 1.) Marek's Disease (HVT) vaccination, 2.) L. animalis (∼106 cfu/50μl), 3.) E. faecium (∼106 cfu/50μl), and 4.) L. animalis + E. faecium (∼106 cfu & ∼106 cfu/50μl each). On day of hatch, hatchability and hatch residue data were recorded. A portion of male chicks from each treatment were placed in a grow-out facility for a 21 d grow-out (18 chicks/pen × 10 pens/treatment = 720 male chicks) with a corn and soy bean meal-based diet without antibiotics or antibiotic alternatives. Performance data and gastrointestinal samples were collected on days 0, 7, 14, and 21. Results indicated no differences in all hatch parameters between treatments (P > 0.05) except for % pipped, where the L. animalis treatment had lower % pipped eggs compared to the HVT control and E. faecium treatments (P = 0.04). No differences were observed in body weight gain or mortality (P > 0.05). Probiotic treatments altered gastrointestinal tissue length, weight, and pH. This resulted in all in ovo injected probiotic treatments increasing feed conversion ratio (FCR) from days 7 to 14 as compared to the control (P = 0.01). Differences in FCR were not observed in any other week of data collection (days 0 to 7, 14 to 21, or 0 to 21; P > 0.05). Although probiotics altered live performance from days 7 to 14, these data suggest that in ovo inoculations of L. animalis and E. faecium in combination are viable probiotic administration practices that potentially improve hatch characteristics and gastrointestinal tract development.

ABSTRACTThe present study aimed to evaluate the effects of excess dietary fluoride (F) on laying performance, egg quality, tissue retention, serum biochemical indices, and serum reproductive hormones of laying hens. A total of 384 Hy-Line Gray hens, 37 wk old, were treated with sodium fluoride added to a corn-soybean meal basal diet at 0, 400, 800, and 1200 mg fluorine/kg feed. The results showed that dietary F levels at 800 and 1200 mg/kg markedly decreased ADFI, laying rate, average egg weight, and increased feed conversion ratio (FCR) (P < 0.05). Dietary F levels at 800 and 1200 mg/kg dramatically decreased the egg quality of albumen height, yolk color, eggshell strength, and eggshell thickness, and on the 49th D, 400 mg/kg F group significantly decreased the eggshell strength, compared to those of control group. Fluoride residues in tissues of hens were increased significantly with the increase of dietary F supplemental levels (P < 0.05). Fluoride concentrations were generally high in feces, eggshell, tibia, kidney, and ovary, and the highest in feces, following with eggshell and tibia, lower in kidney and ovary, and the lowest in serum. Serum uric acid levels and alanine aminotransferase activity increased significantly (P < 0.05), and glucose, triglycerides, and phosphorus decreased significantly (P < 0.05) in response to dietary F concentration, compared to those of the control group, respectively. Dietary F supplementation at 1200 mg/kg significantly decreased (P < 0.05) the estrogen concentrations in serum, compared to those of the control group. Concentrations of progesterone in the fluoride-treated groups were significantly (P < 0.05) decreased relative to those of the control group. In conclusion, these results indicated that the excessive ingestion of F has had a detrimental effect on egg laying rate and quality of eggs by damaging the function of the liver, kidney, and ovary of laying hens.

ABSTRACTInulin, a prebiotic, is an attractive alternative to antibiotic growth promoters in chickens. Dietary supplementation with inulin can improve growth performance, carcass yield, immune system activity, and serum biochemical parameters in chickens. A few studies investigated the impact of dietary inulin supplementation on chicken intestinal microbiota. In this study, we investigated how and why dietary supplementation with 1, 2, and 4% inulin can affect body weight gain, feed intake, food conversion rate, immunological parameters, serum biochemical parameters, and composition and dynamics of the cecal microbiota of Tegel broiler chickens using quantitative fluorescence in situ hybridization (qFISH). We showed that inulin inclusion has a negative effect on growth performance parameters before day 21 and a positive effect subsequently up to day 42. Quantitative FISH data revealed an age-dependent change in the cecal microbiota in the control broilers fed no inulin. Thus, relative abundances of Firmicutes and Actinobacteria decreased from 52.8 to 48.3% of total cells and from 8.7 to 1.4% at days 7 and 42, respectively. However, relative abundances of Bacteroidetes and Proteobacteria gradually increased from 9.3 to 26.9% of the total cells and from 10.7 to 21.1%, respectively, over the same periods. Inulin inclusion appeared to lower the relative abundances of Lactobacillus johnsonii and Bifidobacterium species at an early bird age, but it subsequently significantly (P < 0.05) increased their relative abundances. Such increases positively correlated with body weight gain of the birds, determined after day 21. Thus, dietary supplementation with inulin together with the addition of L. johnsonii and Bifidobacterium (B. gallinarum and B. pullorum) cultures at an early age may help overcome its early negative influence on growth performance. We believe that these findings can improve our knowledge on how inulin can change the intestinal microbiota of broiler chickens and help in developing an inulin feeding regime to optimize its beneficial role in chicken development.