初生肉仔鸡血清和下丘脑摄食调节相关激素的发育规律与品种特点

Developmental Patterns of Serum and Hypothalamic Hormones Regulating Feed Intake in Two Lines of Newly-Hatched Chickens

【目的】研究初生肉仔鸡血清和下丘脑摄食调节相关激素的发育规律并进行品种间比较。【方法】观测了北京油鸡和AA鸡在孵出后0、1、3、5、7、9和11d的采食量,血清和下丘脑的胰岛素和瘦素及下丘脑NPY和α-MSH水平的变化。【结果】北京油鸡和AA鸡的生长规律基本一致,但前者的ADFI和ADG极显著低于后者(P<0.01)。北京油鸡血清胰岛素随日龄的波动较大,而AA鸡除0d外,其它日龄维持在7.5μIU·ml-1左右。北京油鸡血清瘦素在各个日龄间无明显差异,而AA鸡1和3d血清瘦素显著高于0d(P≤0.03)。北京油鸡下丘脑瘦素随日龄增长呈下降趋势,而AA鸡1d下丘脑瘦素高于0d(P<0.01),而后有所降低。2个品种的下丘脑胰岛素和NPY随日龄的变化趋势一致。下丘脑胰岛素在出壳后前5d的水平较高,而后有所下降。下丘脑NPY随日龄增长而上升,其中7d最高。北京油鸡下丘脑α-MSH在出壳后前7d的水平较低,而后有所升高,而AA鸡下丘脑α-MSH随日龄增长而降低,达5d最低,而后又上升。相关分析表明,血清瘦素、下丘脑胰岛素、瘦素和NPY与ADFI的相关性较强,而血清胰岛素和下丘脑α-MSH与ADFI的相关性不强。【结论】血清和下丘脑的摄食相关激素的发育规律因品种和指标不同而异,胰岛素、瘦素、NPY和α-MSH在雏鸡开食过程中可能发挥着一定作用,但其具体调节机制仍需进一步研究。

【Objective】This trial was conducted to study the developmental changes of serum and hypothalamic hormones regulating feed intake in two lines of newly-hatched chickens.【Method】Changes of feed intake, serum insulin and leptin, hypothalamic insulin, leptin, NPY and α-MSH on 0, 1, 3, 5, 7 ,9 and 11th day posthatching in Beijing-You and AA chicks were observed.【Result】Beijing-You chickens grew in a similar pattern with AA chickens, but ADFI and ADG of the former were significantly lower （P≤0.01）. Serum insulin levels of Beijing-You chicks varied greatly with age, while those of AA chicks kept about 7.5 μIU·ml^-1 during the postnatal period except day 0. Serum leptin levels of Beijing-You chicks were not differ significantly with age, while those of AA chicks on day 1 and 3 were higher than that on day 0 （P≤0.03）. Hypothalamic leptin levels of Beijing-You chicks decreased with age, but that of AA chicks on days 1 was higher than that on day 0 （P〈0.01） and then decreased. Similar changes of hypothalamic insulin and NPY with age between both lines were observed. Hypothalamic insulin levels were relatively high during the 5 days posthatching, and then decreased. Hypothalamic NPY levels increased with age, and reached the highest on day 7. Hypothalamic α-MSH levels of Beijing-You chicks were relatively low during the 7 days posthatching, and then increased, while those of AA chicks decreased with age till day 5, and then increased. Correlation analysis showed that ADFI showed high correlations with serum leptin, hypothalamic insulin, lepin and NPY levels, but there were no correlations between ADFI and serum insulin or hypothalamic α-MSH levels.【Conclusion】Developmental changes of serum and hypothalamic hormone levels with age differed in line and parameter. Insulin, leptin, NPY and α-MSH could play a role in regulating feed intake in newly-hatched chickens, but further studies are needed to elucidate the mechanisms.