缺磷日粮对笼养蛋鸡生产性能及内分泌的影响

将 12 0只 19周龄依莎蛋鸡随机分成A、B、C组 ,分别饲喂总磷含量为 5 .8、4 .4和 3.0g/kg的日粮 (相应的有效磷含量分别是 4 .0、2 .5和 1.0 g/kg) ,进行缺磷日粮对蛋鸡生产性能及内分泌的影响试验。结果表明 ,B组与A组间生产性能无显著差异 ;与A、B组相比 ,C组产蛋率、体重、蛋壳品质及骨密度 (BMD)均显著下降 (P <0 .0 1) ;各组间血钙、血磷含量无显著差异 ;C组碱性磷酸酶 (AKP)活性和血液骨钙素 (BGP)含量均比对照组显著提高 (P <0 .0 1) ;从试验开始到产蛋高峰期 (33周龄 ) ,A、B和C组雌二醇 (E2 )水平随年龄增长而上升 ,但随后E2 水平则呈下降趋势。试验结果表明 ,日粮总磷含量为 4 .4 g/kg时有助于提高和改善蛋鸡生产性能 ,若日粮总磷含量低于 4 .4 g/kg ,则会降低产蛋率、蛋重、蛋壳品质及骨量。

Influence of deficient phosphorus levels on the production performance and endocrine in cage layers

One hundred and twenty ISA hens whose age in weeks was 19 were randomly allocated to groups A,B and C fed with dietary levels of total phosphorus of 5.8, 4.4 and 3.0 g/kg respectively. The hens were experimented for 21 weeks in which blood and bone samples were collected to measure blood phosphorus, calcium, alkaline phosphtase(AKP), osteocalcin(BGP), estrogen(E_(2)), tibia bone mineral density(BMD), body weight, eggshell quality and egg production every 2 weeks. It showed that BMD, egg production, body weight and eggshell quality decreased significantly in group C compared with the other two groups(P<0.01). There was no significant variety among different groups in blood calcium and phosphorus. AKP, and BGP in group C increased significantly as compared to the control hens, There were increases in E_(2) levels as with week age raising in three dietary phosphorus groups until high egg production, but after that there was a tendency in decrease of E_(2) levels. E_(2) level of group C was lower than that of groups A, B, although there was no difference in E_(2) among three groups. In conclusion, deficient dietary phosphorus (TP 3.0 g/kg) enhanced levels of AKP and BGP significantly, decreased in egg production , egg shell quality and BMD, and induced osteoporosis.