This study was conducted to investigate the effects of different zinc sources on growth performance, tissue and fecal mineral concentrations, antioxidant capacity and genes expression of zinc related transporters in weaned piglets. A total of 200 weaned piglets (Duroc × Landrace × Yorkshire) with average body weight (BW) of 8.55 ± 0.39 kg were allotted to control group (basal diet) and three treatment groups (basal diet supplemented with 100 mg Zn/kg as ZnSO₄, 100 mg Zn/kg as Zn-Gly and 100 mg Zn/kg as Zn-Met, respectively) for 35 days. The results showed that supplementation with different Zn sources did not influence the average daily feed intake (ADFI). However, weaned piglets fed with Zn supplementation diet had lower diarrhea rate when compared with control group (P < 0.05). In Zn-Gly group, average daily weight gain (ADG) was increased significantly while the feed/gain ratio (F/G) was reduced than those fed with basal diet (P < 0.05). Compared with the control group, red blood cells (RBC), hemoglobin (Hb) and packed cell volume (PCV) in Zn-Gly group were increased significantly and the absolute lymphocytes was decreased (P < 0.05). White blood cell (WBC) and absolute basophils were decreased in Zn supplementation groups (P < 0.05). Meanwhile, the Zn concentration in liver was higher than control group (P < 0.05). In Zn-Gly group, the Zn concentration in tibia and pancreas were promoted compared with control group (P < 0.05). Fecal Zn concentration was the highest in all groups (P < 0.05). But the Zn concentration in serum, kidney and spleen in all groups had no significant differences. In addition, Zn-Gly improved total antioxidant capacity (T-AOC), alkaline phosphatase (AKP) and copper/zinc superoxide dismutase (Cu/Zn SOD) in serum and reduced the level of nitric oxide (NO) (P < 0.05). In liver, the levels of AKP, GSH-Px and T-AOC were enhanced while the levels of NO and MDA were lower when compared with control group (P < 0.05). Results of RT-qPCR showed that metallothionein (MT1) mRNA was upregulated significantly whereas the Zrt/Irt-like proteins (ZIP4) mRNA which is the iron regulatory proteins was downregulated in duodenum (P < 0.05). In jejunum, the expression of MT1 mRNA was upregulated by Zn-Gly and the ZIP4 mRNA was downregulated by ZnSO₄ and Zn-Met (P < 0.05). In summary, the supplementation of different zinc sources for 35 days improved the growth performance and tissue mineral concentration in piglets. Moreover, organic zinc had better effects on antioxidant capacity and the apparent digestion rates of Zn than ZnSO₄.

本研究旨在研究不同锌源对断奶仔猪生长性能，组织和粪便矿物质浓度，抗氧化能力以及锌相关转运蛋白基因表达的影响。将200只平均体重（BW）为8.55±0.39 kg的断奶仔猪（Duroc×Landrace×Yorkshire）分配给对照组（基础饮食）和三个治疗组（基础饮食补充100 mg Zn / kg的ZnSO）_{如图4所示}，分别以100mg Zn / kg作为Zn-Gly和100mg Zn / kg作为Zn-Met）持续35天。结果表明，补充不同的锌源不会影响平均每日饲料摄入量（ADFI）。然而，断奶仔猪饲喂补锌饮食与对照组相比，腹泻率较低（P <0.05）。与基础饮食相比，锌-甘氨酸组的平均日增重（ADG）显着增加，而饲料/增重比（F / G）降低（P  <0.05）。与对照组相比，Zn-Gly组的红细胞（RBC），血红蛋白（Hb）和堆积细胞体积（PCV）显着增加，而绝对淋巴细胞减少（P  <0.05）。补锌组白细胞（WBC）和绝对嗜碱性粒细胞减少（P  <0.05）。同时，肝脏中的锌浓度高于对照组（P  <0.05）。Zn-Gly组与对照组相比，胫骨和胰腺中的Zn浓度升高（P <0.05）。粪便中锌的浓度在所有组中最高（P  <0.05）。但各组血清，肾脏和脾脏中锌的含量无明显差异。此外，Zn-Gly改善了血清中的总抗氧化能力（T-AOC），碱性磷酸酶（AKP）和铜/锌超氧化物歧化酶（Cu / Zn SOD）并降低了一氧化氮（NO）的水平（P  <0.05） 。与对照组相比，肝脏中的AKP，GSH-Px和T-AOC含量升高，而NO和MDA含量较低（P  <0.05）。RT-qPCR结果显示十二指肠中的金属硫蛋白（MT1）mRNA显着上调，而铁调节蛋白Zrt / Irt-like蛋白（ZIP4）mRNA则下调（P <0.05）。在空肠中，MT1 mRNA的表达被Zn-Gly上调，而ZIP4 mRNA的被ZnSO ₄和Zn-Met下调（P  <0.05）。总之，补充35天的不同锌源可改善仔猪的生长性能和组织矿物质浓度。此外，有机锌对锌的抗氧化能力和表观消化率的影响优于ZnSO ₄。