抗热应激药物对肉仔鸡血浆激素及组织学的影响

The Effects of Heat stress preventing additives on Hormones of Plasma and Histology in Broilers

本试验研究了抗应激药物（抗应激Ⅱ、Ⅲ号）对人工高温下肉仔鸡血浆部分激素和组织学的影响。分别于升温至２８℃、３２℃、３６℃后半小时及３６℃维持５天后采血测定。结果表明：抗热应激Ⅱ和Ⅲ号均可降低热应激时肉仔鸡血浆中的ＡＣＴＨ、ＧＬＵ（Ｐ＜０．０５）和皮质酮（Ⅲ号，Ｐ＜０．０１）；使温度上升期间血浆Ｔ３浓度增加（Ｐ＜０．０５）而Ｔ４降低（Ｐ＜０．０５），使在３６℃维持５天的血浆Ｔ３、Ｔ４含量均降低（Ｐ＜０．０５）；升高血中的淋巴细胞，而降低中性粒细胞；减轻热应激时主要器官的组织学改变。提示抗应激Ⅱ、Ⅲ号药物具有较好的抗热应激效果，以饲料中添加０．２２５％的Ⅲ号效果最佳。

This experiment studied the effects of heat-stress-preventing additive ⅡandⅢ on hormones of plasma and histology in broilers.Blood samples were collected after 30 minutes treatment at 28℃、32℃、36℃ and 5 days treatment at 36℃. The resutts showed that under heat stress both additives Ⅱand Ⅲdecreased plasma ACTH, Glu( P< 0 05- 0 01) and corticosterone( only Ⅲ , P< 0 01) ; Plasma T3 concentration Was increased (p<0 05),but plasma T4 declined(P< 0 05- 0 01) with the increase of temperature. However,five days treatment at 36℃ resulted in decrease of both T3 and T4 . Both additives increased the numbers of lymphocytes but declined the numbers of neutrophils in blood, and relieved the histology changes of main organs.these indicated that both additives had better effects on preventing heatstress, and the best effect can be gained with the 0.225% additives concentration.