Li Lan, Zhang Xiaoyi, Zhao Lihong, Zhang Jianyun, Ji Cheng, Ma Qiugang
State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
Animals (Basel). 2021 Dec 14;11(12):3546. doi: 10.3390/ani11123546.
This study evaluated the effects of phosphorus restriction in the brooding stage and subsequent recovery on growth performance, tibia development and early laying performance of layers. 360 one-day-old hens were randomly divided into 4 groups with 6 replicates and 15 chicks per replicate. Chicks were fed diets containing 0.13% (L), 0.29% (M), 0.45% (N), 0.59% (H) non-phytate phosphorus (nPP) from 1 to 8 weeks of age. From 9 to 20 weeks of age, the L and N group were divided into two groups fed normal level phosphorus (n, 0.39% nPP) and high-level phosphorus (h, 0.45% nPP) separately, then all the birds were fed a normal diet (0.39% nPP) from 21 to 26 weeks of age. Four treatments were tested: Ln, Lh, Nn, and Nh. The lower body weight, average daily feed intake, tibia length and daily tibial increment were observed in the L group ( < 0.05) and the ratio of feed to gain was significantly increased in the L group at 8 weeks of age ( < 0.05). In addition, the fresh and degreased tibia weight, bone ash, Ca content in the tibia and P content in the ash and tibia were significantly decreased in the L group at 8 weeks of age ( < 0.05). After compensatory processes, there was no significant difference in tibia characters; however, body weight in the Ln group was significantly lower than in the Nn group ( < 0.05) and was significantly lower in the Lh group than the Nn group ( < 0.01) and Nh group ( < 0.05). In addition, the laying rate and average daily egg mass in the Lh group were lower than Nn and Nh ( < 0.05). In conclusion, severe dietary phosphorus restriction impaired growth performance and bone mineralization in the brooding stage. Subsequent phosphorus supplementation could not alleviate this adverse effect on body weight, which continued to affect egg production. These findings give a foundation and new perspective on a low phosphorus feeding strategy in layer production.
本研究评估了育雏期磷限制及随后恢复对蛋鸡生长性能、胫骨发育和早期产蛋性能的影响。360只1日龄母鸡随机分为4组，每组6个重复，每个重复15只雏鸡。雏鸡在1至8周龄时饲喂含0.13%（低磷组，L）、0.29%（中磷组，M）、0.45%（正常磷组，N）、0.59%（高磷组，H）非植酸磷（nPP）的日粮。9至20周龄时，低磷组和正常磷组再分别分为两组，分别饲喂正常水平磷（n，0.39% nPP）和高水平磷（h，0.45% nPP）日粮，然后所有鸡在21至26周龄时饲喂正常日粮（0.39% nPP）。共测试了四种处理：低磷-正常磷组（Ln）、低磷-高磷组（Lh）、正常磷-正常磷组（Nn）和正常磷-高磷组（Nh）。低磷组的体重、平均日采食量、胫骨长度和胫骨日增长量较低（P<0.05），且8周龄时低磷组的料重比显著升高（P<0.05）。此外，8周龄时低磷组的新鲜胫骨重、脱脂胫骨重、骨灰、胫骨钙含量以及骨灰和胫骨中的磷含量均显著降低（P<0.05）。经过补偿过程后，胫骨特征无显著差异；然而，低磷-正常磷组的体重显著低于正常磷-正常磷组（P<0.05），低磷-高磷组的体重显著低于正常磷-正常磷组（P<0.01）和正常磷-高磷组（P<0.05）。此外，低磷-高磷组的产蛋率和平均日产蛋量低于正常磷-正常磷组和正常磷-高磷组（P<0.05）。综上所述，育雏期严重的日粮磷限制会损害生长性能和骨矿化。随后补充磷并不能缓解对体重的这种不利影响，体重问题会持续影响产蛋。这些研究结果为蛋鸡生产中的低磷饲喂策略提供了依据和新的视角。
