本试验旨在研究不同增钙模式对蛋鸡生产性能、胫骨质量以及血清相关生化指标的影响,以确定蛋鸡生产过程中饲粮钙的增加模式以及钙的添加量。选取18周龄海兰灰商品蛋鸡480只,随机分为4组,每组4个重复,每个重复30只。增钙时间点分别为18周龄以及产蛋率为5%、50%和90%时,各时间点增钙方式分别为:Ⅰ组2.00%、2.20%、2.40%和3.75%;Ⅱ组2.00%、2.50%、3.00%和3.75%;Ⅲ组2.00%、3.00%、3.75%和3.75%;Ⅳ组2.00%、3.75%、3.75%和3.75%。试验期9周。结果表明:1)Ⅲ组蛋鸡产蛋率显著高于Ⅰ组和Ⅳ组(P<0.05),各组间平均日产蛋重差异不显著(P>0.05);2)Ⅲ组胫骨强度、胫骨重、胫骨钙含量显著高于Ⅰ组和Ⅱ组(P<0.05),与Ⅳ组差异不显著(P>0.05);3)蛋鸡产蛋率达50%时,Ⅰ组和Ⅱ组血钙含量显著高于Ⅲ组和Ⅳ组(P<0.05);产蛋率达90%时,Ⅳ组血钙含量显著高于Ⅰ组和Ⅱ组(P<0.05),Ⅲ组与Ⅳ组差异不显著(P>0.05)。结果提示:当蛋鸡产蛋率达5%、50%和90%时,饲粮钙水平分别为3.00%、3.75%和3.75%有助于提高蛋鸡产蛋率,改善体况和稳定骨骼质量,同时不造成钙源浪费。

This study was conducted to investigate the effects of different calcium supplementation modes on production performance, tibia quality and serum biochemical indices of laying hens, with an aim to determine the optimal supplementation mode and amount of calcium in production. Four hundred and eighty 18-week-old Hy-Line Gray commercial layers were divided into 4 groups with 4 replicates each and 30 hens in each replicate. The calcium was supplemented at 18 weeks of age and when the laying rate was 5%, 50% and 90%, respectively. The calcium supplementation modes were:2.00%, 2.20%, 2.40% and 3.75% for group Ⅰ; 2.00%, 2.50%, 3.00% and 3.75% for group Ⅱ; 2.00%, 3.00%, 3.75% and 3.75% for group Ⅲ; 2.00%, 3.75%, 3.75% and 3.75% for group Ⅳ. The experiment lasted for 9 weeks. The results showed as follows:1) the laying rate of hens in group Ⅲ was significantly higher than that in group Ⅰ and group Ⅳ(P<0.05). No significant differences were observed in average daily egg weight among all groups(P>0.05). 2) The tibia strength, weight and calcium content in group Ⅲ were significantly higher than those in group Ⅰ and group Ⅱ(P<0.05), while were not significantly different compared with group Ⅳ(P>0.05). 3) Serum calcium content in group Ⅰ and group Ⅱ was significantly higher than that in group Ⅲ and group Ⅳ when the laying rate was 50%(P<0.05). And serum calcium content in group Ⅳ was significantly higher than that in group Ⅰ and group Ⅱ(P<0.05), but not significantly different compared with group Ⅲ(P>0.05) when laying rate was 90%. In conclusion, the 3.00%, 3.75% and 3.75% calcium supplementation level when the laying rate was 5%, 50% and 90% can improve laying rate and tibia quality of laying hens, and avoid calcium waste.