University of Georgia, Athens, GA 30602, USA.
University of Georgia, Athens, GA 30602, USA.
Poult Sci. 2022 Jun;101(6):101872. doi: 10.1016/j.psj.2022.101872. Epub 2022 Mar 24.
To prevent broiler breeders from growing too quickly and becoming too large for optimum reproduction, their dietary intake is restricted. While current restricted feeding programs, such as skip-a-day feeding (SAD), improve the economic efficiency of broiler breeder operations, this management practice impacts bird welfare. There is an interest in finding strategies that could reduce the impact of feed restriction during broiler breeder rearing. This research investigated the effects of feeding pullets on an advanced growth curve for early photostimulation at 15 wk (15P) or standard growth curve for photostimulation at 21 wk (21P), using either an every-day-spin feeding program (EDS) or SAD feeding, on the reproductive parameters of broiler breeder hens in a 2 × 2 factorial arrangement. Overall, advancing the growth curve (15P) decreased blood corticosterone levels compared to 21P, but EDS resulted in higher blood corticosterone levels compared to SAD. At the end of rearing in both 15P and 21P, EDS pullets weighed less than SAD pullets. The onset of egg production was 20 and 24 wk of age for the 15P and 21P hens, respectively. Despite an earlier onset, 15P hens did not produce more eggs than 21P hens through 65 wk of age. Egg weight was reduced for 15P compared to 21P until 30 wk of age. The 15P hens had a greater number of double yolk eggs than the 21P hens. Fertility and hatch were not impacted by the advanced growth curve and early photostimulation. Although the current research indicates the potential to reduce feed restriction associated welfare issues by rearing broiler breeder pullets for an earlier photostimulation onset, further research in needed to determine if this management technique can be improved to optimize hen reproductive efficiency.
为了防止肉鸡种鸡生长过快、体型过大而影响最佳繁殖性能,会对其采食量进行限制。虽然目前的限饲方案,如隔日限饲(SAD),提高了肉鸡种鸡养殖的经济效益,但这种管理方式会影响鸡只的福利。因此,人们希望找到一些策略,以减少肉鸡种鸡育雏期间的饲料限制对其造成的影响。本研究采用 2×2 析因试验设计,以每日旋转采食方案(EDS)或 SAD 对肉鸡种鸡进行限饲,研究了在 15 周龄(15P)采用提前生长曲线(提前进行光照刺激)或 21 周龄(21P)采用标准生长曲线(21P)进行光照刺激对种母鸡繁殖性能的影响。总体而言,与 21P 相比,提前生长曲线(15P)会降低血液皮质酮水平,但 EDS 会导致血液皮质酮水平高于 SAD。在育雏期结束时,15P 和 21P 的 EDS 组种鸡体重均低于 SAD 组。15P 和 21P 母鸡的产蛋起始日龄分别为 20 周龄和 24 周龄。尽管 15P 母鸡的产蛋起始日龄更早,但直到 65 周龄,15P 母鸡的产蛋数均未多于 21P 母鸡。与 21P 相比,15P 母鸡的蛋重直到 30 周龄才有所下降。与 21P 相比,15P 母鸡的双黄蛋数量更多。提前生长曲线和光照刺激对受精率和孵化率没有影响。虽然本研究表明,通过提前光照刺激来育雏,可减少与限饲相关的福利问题,但仍需要进一步研究,以确定这种管理技术是否可以进一步优化母鸡的繁殖效率。