Western Paraná State University-Marechal Cândido Rondon, Cascavel, Paraná, Brazil.
State University of Maringá, Maringá, Paraná, Brazil.
J Anim Physiol Anim Nutr (Berl). 2024 Jan;108(1):264-273. doi: 10.1111/jpn.13885. Epub 2023 Oct 2.
This work evaluated the influence of vitamin A on performance, organ weight, and bone and skin characteristics in broilers (Cobb 500) at 21 and 42 days of age. A total of 1920 chickens were distributed in a randomised design, considering six vitamin A supplementation levels (0, 6000, 16,000, 26,000, 36,000, and 46,000 IU kg ), with 16 replicates and 20 chickens per experimental unit, established due to rising the range of vitamin levels observed in the literature to evaluate the effect of vitamin A on broilers. At 22 days, half of the replicates from each treatment continued receiving the initial diet, and the other eight repetitions received diets without vitamin A (0 IU kg ) until 42 days. The level of vitamin A influenced feed intake (FI) and body weight gain (BWG) until 21 days for all treatments. Broilers at 21 days of age had a more significant BWG at a vitamin A supplementation level of 28,209 IU kg . At 42 days, vitamin A influenced the BWG and FI of broilers at treatments that were not supplemented after 21 days. Treatments supplemented up to 42 days showed quadratic responses to vitamin A for BWG, FI, and feed conversion. The vitamin A levels influenced the relative weights of the small intestine, pancreas, gizzard, abdominal fat, Seedor index, and breaking strength at 42 days, where the adequate supplementation of vitamin A improved these characteristics in broilers. Vitamin A supplementation from 22 to 42 days old did not affect broiler performance. An increased BWG was obtained when vitamin A supplementation occurred until 42 days, with supplementation of 29,375 IU kg and a lower response of feed conversion with the addition of 27,775 IU kg .
本研究评估了维生素 A 对 21 和 42 日龄肉鸡（科宝 500）生产性能、器官重量、骨骼和皮肤特性的影响。1920 只鸡采用随机设计分配，考虑了 6 种维生素 A 补充水平（0、6000、16000、26000、36000 和 46000 IU kg ），每个处理 16 个重复，每个重复 20 只鸡，这是因为增加了文献中观察到的维生素水平范围，以评估维生素 A 对肉鸡的影响。在 22 天，每个处理的一半重复继续接受初始饮食，而其他八个重复接受不含维生素 A（0 IU kg ）的饮食，直到 42 天。在所有处理中，维生素 A 水平直到 21 天都影响饲料摄入量（FI）和体重增加（BWG）。21 日龄的肉鸡在维生素 A 补充水平为 28209 IU kg 时具有更显著的 BWG。在 42 天，在 21 天后不补充维生素 A 的处理中，维生素 A 影响肉鸡的 BWG 和 FI。补充至 42 天的处理对 BWG、FI 和饲料转化率表现出二次响应。维生素 A 水平影响小肠、胰腺、肌胃、腹部脂肪、Seedor 指数和断裂强度的相对重量42 天，适当补充维生素 A 可改善肉鸡的这些特性。22 至 42 天补充维生素 A 不会影响肉鸡的性能。当维生素 A 补充持续到 42 天，获得了更高的 BWG，补充 29375 IU kg ，添加 27775 IU kg 可获得更低的饲料转化率响应。
