Department of Animal Science, Federal University of Rio Grande do Sul, Porto Alegre, RS, 91540-000, Brazil.
Poult Sci. 2019 Jan 1;98(1):172-178. doi: 10.3382/ps/pey382.
Two experiments were conducted to compare the immunocompetence of Cobb high performance and rustic Label Rouge broilers and the influence of reduced growth rates subsequent to feed restriction on the IgY anti-bovine serum albumin (BSA) response. In the first experiment (EXP), 360 broilers were assigned to 36 cages from 1 to 42 days of age. A completely randomized design was applied in a 3 × 2 factorial arrangement, with 3 groups (Label Rouge, Cobb ad libitum, and Cobb Restricted Intake), and 2 levels of energy (3,100 and 2,800 kcal/kg); there were 6 replicates per treatment. In the second EXP, 384 Cobb 500 male broilers were randomly assigned to the following feed restriction programs from day 8 to 16: Control, fed ad libitum; Quantitative (80% of the control amount); By Time (fed for 8 h/d), and Qualitative (80% limiting nutrients) restriction. Blood samples were collected on days 35 and 42 (EXP 1) and weekly from day 7 to 42 (EXP 2) for IgY anti-BSA quantification. In EXP 1, the production of IgY anti-BSA was lower in the Cobb groups (P < 0.0001) than in the Label Rouge group, and higher in the Cobb Restricted Intake group (P < 0.0001) compared with the same genetic strain fed ad libitum. Birds fed the low energy diet presented lower (P ≤ 0.06) IgY anti-BSA, independent of genetics. In EXP 2, no difference (P > 0.05) was observed 1 wk after the first BSA inoculation. However, at day 28, birds in all feed restriction programs had higher (P < 0.05) IgY anti-BSA than the Control group fed ad libitum. At day 35, the greatest residual effect of IgY anti-BSA was observed in the Quantitative restriction group. No differences (P > 0.05) were observed between groups after 42 d. The 3 early feed restriction programs had beneficial effects on the humoral immune response. Overall, Quantitative restriction promoted a longer lasting IgY anti-BSA response. Lower growth rate, due to feed restriction or genetic potential, improves humoral immunity in broiler chickens.
进行了两项实验来比较科布高性能和乡村 Label Rouge 肉鸡的免疫能力，以及在限制生长速度后对 IgY 抗牛血清白蛋白 (BSA) 反应的影响。在第一个实验 (EXP) 中，从 1 日龄到 42 日龄，将 360 只肉鸡分配到 36 个笼子中。采用完全随机设计，进行 3 × 2 因子排列，分为 3 组（Label Rouge、Cobb 自由采食和 Cobb 限制采食量），2 种能量水平（3100 和 2800 kcal/kg）；每个处理有 6 个重复。在第二个实验 (EXP) 中，从第 8 天到第 16 天，将 384 只 Cobb 500 只雄性肉鸡随机分配到以下饲料限制方案中：对照组，自由采食；定量（对照组的 80%）；按时（每天喂食 8 小时）和定性（限制 80%限制营养素）限制。在 EXP 1 中，与 Label Rouge 组相比，Cobb 组（P < 0.0001）的 IgY 抗 BSA 产量较低，而 Cobb 限制摄入量组（P < 0.0001）则高于同一遗传品系的自由采食组。饲喂低能量日粮的鸡的 IgY 抗 BSA 较低（P ≤ 0.06），与遗传无关。在 EXP 2 中，首次接种 BSA 后 1 周没有观察到差异（P > 0.05）。然而，在第 28 天，所有饲料限制方案的鸡的 IgY 抗 BSA 均高于自由采食的对照组（P < 0.05）。在第 35 天，定量限制组观察到 IgY 抗 BSA 的最大残留效应。42 天后，各组之间没有差异（P > 0.05）。前 3 个早期饲料限制方案对体液免疫反应有有益影响。总的来说，定量限制促进了更长时间的 IgY 抗 BSA 反应。由于饲料限制或遗传潜力导致的生长速度降低可提高肉鸡的体液免疫能力。
