Poultry R&D, Trouw Nutrition, EL Viso de San Juan, Toledo 45215, Spain.
Poultry R&D, Trouw Nutrition, EL Viso de San Juan, Toledo 45215, Spain.
Poult Sci. 2023 Sep;102(9):102860. doi: 10.1016/j.psj.2023.102860. Epub 2023 Jun 12.
Modifying dietary amino acids has been proposed as a strategy to improve eggshell quality by slowing down increases in egg weight (EW). This study aimed to investigate the effects of different levels of digestible lysine (dLYS) and ratios of digestible sulfur amino acids (dTSAA) to dLYS on performance and eggshell quality in ISA brown hens. A total of 288 hens were individually housed and assigned to 8 treatments, which combined 2 levels of dLYS (5.9 and 5.5 g/kg) with 4 ratios of dTSAA:dLYS (90, 85, 80, and 75) in a factorial arrangement. The study lasted 12 wk, starting at 62 wk of age. The number of eggs was not affected by the interaction between dLYS and dTSAA:dLYS or their main effect. However, the interaction between dLYS and dTSAA:dLYS showed that reducing the dTSAA:dLYS ratio from 85 to 75 when hens were fed 5.5 g/kg of dLYS resulted in a lower EW. Conversely, when hens were fed 5.9 g/kg of dLYS, no significant difference was found in EW among the different ratios of dTSAA:dLYS. Although there was no interaction between the levels of dLYS and dTSAA:dLYS on eggshell quality, reducing the dLYS level from 5.9 to 5.5 slowed down the deterioration in eggshell-breaking strength and eggshell thickness, regardless of the dTSAA:dLYS ratio. These findings suggest that adjusting dietary dLYS while maintaining the dTSAA:dLYS ratio of no less than 85 may be an effective strategy for decelerating the deterioration of eggshell quality in laying hen operations without impacting the egg production rate.
通过减缓蛋重（EW）的增加来改善蛋壳质量，已经提出了改变日粮氨基酸的策略。本研究旨在研究不同可消化赖氨酸（dLYS）水平和可消化含硫氨基酸（dTSAA）与 dLYS 比值对 ISA 褐壳蛋鸡生产性能和蛋壳质量的影响。将 288 只母鸡单独饲养，并将其分配到 8 个处理组中，每个处理组组合了 2 个 dLYS 水平（5.9 和 5.5 g/kg）和 4 个 dTSAA:dLYS 比值（90、85、80 和 75）。研究持续了 12 周，从 62 周龄开始。dLYS 和 dTSAA:dLYS 的互作及其主效均不影响蛋数。然而，dLYS 和 dTSAA:dLYS 的互作表明，当母鸡饲喂 5.5 g/kg 的 dLYS 时，将 dTSAA:dLYS 比值从 85 降低到 75 会导致 EW 降低。相反，当母鸡饲喂 5.9 g/kg 的 dLYS 时，不同 dTSAA:dLYS 比值之间的 EW 没有显著差异。尽管 dLYS 和 dTSAA:dLYS 水平之间没有互作，但降低 dLYS 水平（从 5.9 降至 5.5）可减缓蛋壳破蛋强度和蛋壳厚度的恶化，而与 dTSAA:dLYS 比值无关。这些发现表明，在不影响产蛋率的情况下，调整日粮 dLYS 同时保持 dTSAA:dLYS 比值不低于 85，可能是延缓蛋鸡生产中蛋壳质量恶化的有效策略。
