Li Wenjia, Wei Fengxian, Xu Bin, Sun Quanyou, Deng Wen, Ma Huihui, Bai Jie, Li Shaoyu
Institute of Animal Husbandry and Veterinary Science, Henan Academy of Agricultural Sciences, Zhengzhou, Henan 450003, China.
Asian-Australas J Anim Sci. 2019 Dec 1;32(12):1914-1922. doi: 10.5713/ajas.18.0939. Epub 2019 Apr 15.
The study was conducted to evaluate the effect of stocking density and alpha-lipoic acid (ALA) on the growth performance, feed utilization, carcass traits, antioxidative ability and immune response of broilers.
A total of 1530 22-day-old male broilers (Arbor Acres) with comparable body weights (731.92 ± 5.26) were placed into 18 cages (2.46 × 2.02 m) in groups of 75 birds (15 birds/m2, 37.5 kg/m2; LD, low stocking density), 90 birds (18 birds/m2, 45.0 kg/m2; HD, high stocking density) and 90 birds with 300 mg/kg ALA added to the basal diet (18 birds/m2, 45.0 kg/m2; HD+ALA, high stocking density + -lipoic acid); each treatment was represented by 6 replicates. The experimental period was 3 weeks.
The results showed that the high stocking density regimen resulted in a decreased growth, feed conversion ratio, carcass weight, thigh yield and bursa weight relative to body weight (P < 0.05) on d 42. The abdominal fat yield in the HD+ALA group was lower (P = 0.031) than that of the LD group at 42 d. The superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in serum were increased, and malondialdehyde (MDA) content decreased after adding ALA product (P < 0.05) on d 42. Additionally, the serum concentrations of IgA and IgG were decreased (P < 0.05) and the level of diamine oxidase (DAO) was higher (P < 0.01) in the HD group on d 42.
The high stocking density significantly decreased broiler growth performance, feed utilization and carcass traits, increased physiological and oxidative stress and induced intestinal mucosal injury. The supplementation of ALA product in broiler diet at 300 mg/kg may reduce the adverse effects of high stocking density-mediated stress by maintaining the antioxidant system and humoral immune system.
本研究旨在评估饲养密度和α-硫辛酸（ALA）对肉鸡生长性能、饲料利用率、胴体性状、抗氧化能力和免疫反应的影响。
将1530只体重相当（731.92±5.26）的22日龄雄性艾维茵肉鸡分成18个笼子（2.46×2.02米），每组分别为75只鸡（15只/平方米，37.5千克/平方米；低密度组，LD）、90只鸡（18只/平方米，45.0千克/平方米；高密度组，HD）和90只在基础日粮中添加300毫克/千克ALA的鸡（18只/平方米，45.0千克/平方米；高密度+ALA组，HD+ALA）；每个处理设6个重复。试验期为3周。
结果表明，在第42天时，与低密度组相比，高密度饲养方案导致肉鸡生长速度、饲料转化率、胴体重、大腿产率和相对于体重的法氏囊重量降低（P＜0.05）。在第42天时，HD+ALA组的腹脂产率低于LD组（P = 0.031）。在第42天时，添加ALA产品后，血清中超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GSH-Px）活性升高，丙二醛（MDA）含量降低（P＜0.05）。此外，在第42天时，HD组血清中IgA和IgG浓度降低（P＜0.05），二胺氧化酶（DAO）水平升高（P＜0.01）。
高饲养密度显著降低了肉鸡的生长性能、饲料利用率和胴体性状，增加了生理和氧化应激，并导致肠道黏膜损伤。在肉鸡日粮中添加300毫克/千克的ALA产品，可能通过维持抗氧化系统和体液免疫系统来减轻高饲养密度介导的应激的不利影响。
