Laboratory of Quality & Safety Risk Assessment for Animal Products on Feed Hazards (Beijing) of the Ministry of Agriculture and Rural Affairs Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; College of Biological Engineering, Henan University of Technology, No. 100 Lianhua Street, Zhengzhou, Henan Province 450001, China.
Laboratory of Quality & Safety Risk Assessment for Animal Products on Feed Hazards (Beijing) of the Ministry of Agriculture and Rural Affairs Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Poult Sci. 2021 Oct;100(10):101376. doi: 10.1016/j.psj.2021.101376. Epub 2021 Jul 9.
We investigated the effect of photoperiod on eggshell quality, bone quality characteristics and bone metabolism related enzymes and factors in laying ducks. After adaption, 300 Jinding laying ducks (252-day-old) were randomly divided into 5 treatments, receiving 12L (hours of light):12D (hours of darkness), 14L:10D, 16L:8D, 18L:6D or 20L:4D, respectively. Each group had 6 replicates of 10 birds each. The feeding experiment lasted 8 wk. Compared with 12L:12D, the higher values of eggshell breaking strength occurred in ≥18 h photoperiods at the end of 6 wk, and in ≥16 h photoperiods at the end of 4 wk, with the common highest values in 18 h photoperiod (P ˂ 0.05). Besides, 18L:6D had higher values of ultimate load Fu and cortical cross-sectional area A in tibia, femur, and ulna (P ˂ 0.05), compared with 12L:12D. The higher values of proximal bone mineral content (BMC; tibia), distal BMC (ulna), total Ca (tibia), and cortical volumetric bone mineral density (vBMC; tibia and ulna) were observed in 16L:8D and 18L:6D treatments (P ˂ 0.05). Meanwhile, 18 h photoperiod group had the higher proximal BMC (femur) and total Ca in ulna (P ˂ 0.05). In serum, compared with 12L:12D group, the higher ALP activity occurred in ≥16 h photoperiods (0:00 and 18:00), with the highest values in 18L:6D treatment (P ˂ 0.05); the higher values of TGF-β (6:00) and OC (6:00 and 18:00) were simultaneously observed in 18 h photoperiod (P ˂ 0.05). Moreover, values of trACP activity, TNF-α and IL-6 contents decreased in ≥18 h photoperiods at 0:00 (P ˂ 0.05), compared with 12L:12D group. To sum up, an appropriate photoperiod could improve eggshell quality, bone strength and mineral content through increasing osteogenesis during the light time and decreasing resorption activity during the dark, and 18 h is an adequate photoperiod for the eggshell and bone quality of laying ducks.
我们研究了光周期对产蛋鸭蛋壳质量、骨骼质量特征以及与骨代谢相关的酶和因子的影响。经过适应期后，将 300 只金定产蛋鸭（252 日龄）随机分为 5 个处理组，分别接受 12L（光照时间）：12D（黑暗时间）、14L:10D、16L:8D、18L:6D 或 20L:4D。每组有 6 个重复，每个重复 10 只鸟。饲养实验持续 8 周。与 12L:12D 相比，6 周末 18h 以上光周期的蛋壳破裂强度较高，4 周末 16h 以上光周期的蛋壳破裂强度较高，18h 光周期的蛋壳破裂强度最高（P ˂ 0.05）。此外，18L:6D 处理的胫骨、股骨和尺骨的最终载荷 Fu 和皮质横截面积 A 较高（P ˂ 0.05），与 12L:12D 处理相比。16L:8D 和 18L:6D 处理的胫骨近端骨矿物质含量（BMC）、远端 BMC（尺骨）、总钙（tibia）和皮质体积骨矿物质密度（vBMC；胫骨和尺骨）较高（P ˂ 0.05）。同时，18h 光周期组的胫骨近端 BMC（股骨）和尺骨总钙较高（P ˂ 0.05）。血清中，与 12L:12D 组相比，16h 以上光周期（0:00 和 18:00）的碱性磷酸酶（ALP）活性较高，18L:6D 处理的 ALP 活性最高（P ˂ 0.05）；18h 光周期同时观察到 TGF-β（6:00）和 OC（6:00 和 18:00）较高（P ˂ 0.05）。此外，18h 以上光周期（0:00）时，trACP 活性、TNF-α 和 IL-6 含量降低（P ˂ 0.05），与 12L:12D 组相比。综上所述，适当的光周期可以通过增加光照时间的成骨作用和减少暗时间的吸收活性来提高蛋壳质量、骨骼强度和矿物质含量，18h 是产蛋鸭蛋壳和骨骼质量的适宜光周期。
