Faculdade de Ciências Agrárias e Veterinárias, UNESP Univ Estadual Paulista, Jaboticabal, São Paulo, Brazil.
J Anim Physiol Anim Nutr (Berl). 2019 Jul;103(4):1107-1115. doi: 10.1111/jpn.13101. Epub 2019 Apr 25.
The objective of this work was to determine the efficiency of utilization (EU) and produce factorial models for optimal isoleucine (Ile) intake. Six dose-response trials were carried out, three for males and three for females, with 640 Ross 308 in each studied phase. The initial (1-14 days), grower (15-28 days) and finisher (29-42 days) phases were evaluated to cover the growing phase of the broiler chicken. In total, eight treatments were randomly distributed to four replicates of 20 birds each. The treatments consisted of seven crescent levels of Ile and one counter proof to ensure that Ile was the first limiting amino acid in the diet. Dilution technique was applied to produce the levels of Ile and keep the amino acid ratio with lysine. The EU was determined to account for whole body or partitioned for feather-free body (Bff) and feather. Two distinct factorial models were adjusted, M1 and M2. The M2 model was evaluated for one or two EU, being denominated as M2 and M3. When the efficiency was partitioned, the values of 53% and 69% for feather and Bff were determined. The optimal Ile intake estimated for each model were of 275, 908, 1,412 mg of Ile/bird/day (M1); 258, 829, 1,321 mg of Ile/bird/day (M2); and 284, 835, 1,288 mg of Ile/bird/day (M3) for initial, grower and finisher phases respectively. The EU partitioned for feather-free body and feather reduced the biased of the model M3. Overall, higher values of Ile intake are estimated when model M1 is used, which may be the difference in account for body weight gain (M1) or only protein gain (M2 and M3) to estimate the amount of amino acid required for broiler.
本研究旨在确定肉鸡的理想异亮氨酸（Ile）摄入量及其利用效率（EU），并建立相应的因子模型。试验共开展了 6 个剂量反应试验，其中 3 个为雄性试验，3 个为雌性试验，每个试验阶段有 640 只 Ross 308 肉鸡。试验分别评估了 1-14 日龄、15-28 日龄和 29-42 日龄的雏鸡生长期，共 8 种处理方式，每种处理方式均设置 4 个重复，每个重复 20 只鸡。处理方式由 7 个递增的 Ile 水平和 1 个对照组成，以确保 Ile 是日粮中的第一限制氨基酸。试验采用稀释技术来配制不同水平的 Ile 并保持赖氨酸与其他氨基酸的比例。本研究确定了 EU 来评估整个机体或无羽毛体（Bff）和羽毛的分配效率。共建立了 2 种因子模型，M1 和 M2。M2 模型可以进一步调整为 M2 和 M3 模型来评估 1 或 2 种 EU。当 EU 进行分区时，羽毛和 Bff 的效率分别为 53%和 69%。M1、M2 和 M3 模型估计的初始、生长和育肥阶段的最佳 Ile 摄入量分别为 275、908 和 1412mg 异亮氨酸/只/天、258、829 和 1321mg 异亮氨酸/只/天、284、835 和 1288mg 异亮氨酸/只/天。M3 模型将 EU 分配到无羽毛体和羽毛中，降低了模型的偏倚。总的来说，当使用模型 M1 时，估计的 Ile 摄入量更高，这可能是由于模型 M1 考虑了体重增加（M1）或仅考虑了蛋白质增加（M2 和 M3）来估计肉鸡所需的氨基酸量。
