生长早期泰和鸡与AA鸡血清生长激素水平及生长激素结合蛋白活性的比较

Comparison of growth hormone levels and the binding activities of growth hormone binding protein in the plasma of Taihe and AA broiler chickens during early posthatch development

比较泰和鸡和AA (ArborAcres)肉鸡血清生长激素 (GH)含量和生长激素结合蛋白 (GHBP)的结合活性 ,发现两品种鸡出雏时血清GH水平均较低 ,5日龄时GH均有显著上升 (P <0 0 1)。此后泰和鸡保持上升趋势 ,在 35日龄GH达到最高值 ;而AA鸡在 5日龄后血清GH水平上升幅度较小 ,日龄间差异不显著。 1日龄和 35日龄时 ,泰和鸡血清GH水平显著高于同日龄的AA肉鸡 ,与两者体重的差异刚好相反。血液GHBP活性均在出雏时较高 ,品种间差异不显著 ,5日龄时都极显著地下降 (P <0 0 1) ;AA鸡虽直至 35日龄都保持较低水平 ,5 0日龄时又显著回升 (P <0 0 5 ) ;而泰和鸡 5日龄后一直保持低水平 ,5 0日龄有升高趋势 ,但差异不显著。在 5 ,10和 5 0日龄 ,泰和鸡血中GHBP的结合活性显著低于AA肉鸡 (P <0 0 5 ,P =0 0 5 ,P <0 0 1)。

The plasma levels of growth hormone(GH)and binding activities of serum growth hormone binding protein(GHBP)of Taihe chickens were measured in comparison with that of Arbor Acres(AA)chickens at 1(D1),5,10,35 and 50 days of age.Plasma GH concentrations were low at hatch,followed by a significant increase at D5 in both strains of chicken.GH plasma concentrations in Taihe chicken were keeping increase thereafter till D35 when the peak value was reached.In AA chickens,however,no significant developmental changes in GH plasma levels were observed after D5 in spite of a tendency of up-regulation.Taihe chickens exhibited significantly higher plasma GH levels than AA chickens at D1 and D35,being inversely correlated with body weight.Serum GHBP activities were high at hatch,followed by a significant decrease at D5 in both strains of chicken.An up-regulation was observed in both strains of chicken from D35 to D50 when the growth rate was declined.Serum GHBP activities in Taihe chicken were significantly lower than that of AA chickens at D5,D10 and D50.A clear negative relationship was observed between serum GHBP activities and plasma GH levels.