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

Effects of Continuous Partial Heat Treatment on Immune Organ Indexes,Small Intestinal Morphology and Mucosal Immunity Indexes of Broiler Chickens

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(SIg A)含量,26和31℃处理显著降低第7天十二指肠SIg A含量;31℃处理显著降低第1天空肠SIg A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。

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 ℃ and60% relative humidity. When broiler chickens were 29-day-old,the temperatures of each environmental chamber were gradually regulated to 21,26 and 31 ℃,respectively,while maintaining the relative humidity 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）. The31 ℃ 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 significantly reduced the secretory immunoglobulin A（ SIg A） content of duodenum on day 1. The 26 and 31 ℃ treatments significantly reduced SIg A content of duodenum on day 7. The 31 ℃ treatment significantly reduced SIg A 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 reduce immune function of intestinal mucosa to varying degrees.