持续偏热处理对肉仔鸡免疫器官指数、小肠形态结构和黏膜免疫指标的影响

摘要

This experiment was conducted to study the effects of different continuous partial heat ( 26 and 31 ℃) treatments on immune organ indexes, small intestinal morphology and mucosal immunity indexes of broiler chickens. One hundred and forty-four 22-day-old Arbor Acres ( AA) broiler chickens were assigned to three environment chambers ( treatments) , each chamber contained six cages ( replicates) with eight birds per cage ( with four males and four females) . The pre-test period lasted for 7 days and broiler chickens were kept at 21 ℃ and 60% relative humidity. When broiler chickens were 29-day-old, the temperatures of each environ-mental chamber were gradually regulated to 21, 26 and 31 ℃, respectively, while maintaining the relative hu-midity at 60% and both kept constant until the end of the experiment. The trial period lasted for 14 days. The results showed as follows: compared with 21 ℃ treatment, 1) temperature treatments had no significant effect on the thymus index of broiler chickens ( P>0.05) . On day 7, 31 ℃ treatment significantly reduced the spleen index ( P<0.05) . The 31 ℃ treatment significantly reduced the bursa index on days 7 and 14 ( P<0.05) . 2) The 26 and 31℃ treatments significantly reduced the villus height of jejunum and ileum on day 14 ( P<0.05) . The 31 ℃ treatment significantly increased crypt depth of jejunum on day 14 (P<0.05). The 26 and 31 ℃treatments significantly increased the crypt depth of ileum on day 14 ( P<0.05) . 3) The 31℃ treatment signif-icantly reduced the secretory immunoglobulin A ( SIgA) content of duodenum on day 1. The 26 and 31 ℃treatments significantly reduced SIgA content of duodenum on day 7. The 31 ℃ treatment significantly reduced SIgA content of jejunum on day 1. In conclusion, compared with 21 ℃ treatment, the partial heat ( 26 and 31 ℃) treatments can affect the development of immune organs, damage small intestinal morphology and re-duce immune function of intestinal mucosa to varying degrees.%本试验研究了不同持续偏热( 26和31 ℃)处理对肉仔鸡免疫器官指数、小肠形态结构和黏膜免疫指标的影响. 试验选取22日龄爱拔益加( AA)肉仔鸡144只转入人工气候实验舱,随机分成3个处理,每个处理6个重复,每个重复8只(公母各占1/2). 适应期7 d,温度21 ℃,相对湿度60%. 29日龄时,试验温度分别调整到21、26和31 ℃,相对湿度60%,至试验结束,试验期共14 d. 结果表明:与21 ℃处理相比,1)26和31 ℃处理对肉仔鸡胸腺指数无显著影响( P>0.05);第7天,31 ℃处理显著降低脾脏指数( P<0.05);第7、14天,31 ℃处理显著降低法氏囊指数(P<0.05). 2)26和31℃处理显著降低第14天空肠和回肠绒毛高度(P<0.05);31 ℃处理显著升高第14天空肠隐窝深度( P<0.05);26 和31 ℃处理显著升高第14 天回肠隐窝深度(P<0.05). 3)31 ℃处理显著降低第1 天十二指肠分泌型免疫球蛋白 A(SIgA)含量,26 和31 ℃处理显著降低第7天十二指肠SIgA含量;31 ℃处理显著降低第1天空肠SIgA含量. 因此,与21 ℃处理相比,持续偏热( 26和31 ℃)处理不同程度影响肉仔鸡免疫器官的发育,损伤小肠形态结构,降低小肠黏膜免疫功能.