ABSTRACT

1. As the use of antibiotics as growth promoters has been banned in many regions, there has been an on-going search for possible alternative compounds, such as prebiotics and organic acids.

2. This study was conducted to investigate the influence of liquid whey (LW) and organic acid (ACIDAL® ML) supplementation on performance, eggs characteristics, gut pH and health status in laying hens.

3. Seven hundred and fifty, Isa Brown chicks were randomly assigned to five treatments groups (n = 150) and each treatment had five replicates of 30 birds each. The birds were reared for 48 weeks. The treatments were administered in the drinking water at doses of: 250 ml/l of LW (Lacto25), 500 ml/l of LW (Lacto50) or 1 ml/l of ACIDAL® ML (Aci). A positive control group (T+) was treated with 500 mg/l of Tetracolivit (an antibiotic). The negative control group (T-) did not receive any treatment in the drinking water.

4. Administration of LW or ACIDAL® ML in the drinking water reduced (P < 0.05) the pH in the crop, proventriculus, ileum and caeca, as well as total coliform bacteria and E. coli, but increased Lactobacillus spp. in the ileum and caecum, compared to the negative control.

5. Oviposition was earlier in the birds in both the Lacto50 and Aci groups. The weight of birds at first lay and point of lay in the four treated groups was higher than those in negative control group. Furthermore, egg production was increased by 10.44% in birds receiving Lacto25, but the weight and quality traits were unaffected, while the egg shell ratio was higher in the Aci group compared to the other treatments.

6. The data indicated that addition of LW or ACIDAL® ML improved hens’ performance by modifying gut pH and microflora.

摘要

1. 由于许多地区已禁止使用抗生素作为生长促进剂，因此一直在寻找可能的替代化合物，例如益生元和有机酸。

2. 本研究旨在调查添加液态乳清 (LW) 和有机酸 (ACIDAL® ML) 对蛋鸡生产性能、鸡蛋特性、肠道 pH 值和健康状况的影响。

3. 750 只 Isa Brown 雏鸡被随机分配到五个处理组（n = 150），每个处理有 5 个重复，每组 30 只鸡。这些鸟饲养了48周。在饮用水中进行处理，剂量为：250 ml/l LW (Lacto25)、500 ml/l LW (Lacto50) 或 1 ml/l ACIDAL® ML (Aci)。用 500 mg/l Tetracolivit（一种抗生素）处理阳性对照组 (T+)。阴性对照组（T-）在饮用水中未接受任何处理。

4. 在饮用水中施用 LW 或 ACIDAL® ML 可降低（P < 0.05）作物、腺胃、回肠和盲肠的 pH 值，以及总大肠菌群和大肠杆菌，但增加乳酸杆菌属。在回肠和盲肠，与阴性对照相比。

5. Lacto50 和 Aci 组的鸟类产卵时间较早。四个处理组的初产和产蛋时重均高于阴性对照组。此外，接受 Lacto25 的鸡只的产蛋量增加了 10.44%，但体重和质量性状不受影响，而与其他处理相比，Aci 组的蛋壳率更高。

6. 数据表明，添加 LW 或 ACIDAL® ML 通过改变肠道 pH 值和微生物区系来提高母鸡的生产性能。