持续日变高温对肉鸡矿物质代谢的影响

Effects of long term heat exposure on metabolism of chromium and other minerals for broilers

为研究持续日变高温环境对肉仔鸡矿物质代谢的影响,选用体重接近的20只肉仔鸡,随机分为两组,另选体重接近的4只肉仔鸡,施人工肛门手术。试验组持续日变高温环境设为25～35℃,其中每日35℃持续3h。对照组为20℃恒温。在人工气候舱内适应8d后,每只鸡收集3d尿和总排泄物,并对其中矿物质排出量进行测量,分别对试验前及试验结束时血液中矿物质浓度进行测量。结果表明:持续日变高温使肉仔鸡血清中K浓度显著下降,Zn浓度上升,其它矿物质元素浓度无显著变化,在限饲相同进食量情况下,热应激使K、P、Mg、Na和Co的排出量明显低于对照组,而其它矿物元素排出量与对照组无显著差异,尿中矿物质浓度无显著变化。

Avian broilers at 10 weeks old of age were used to study the effect of sustained heat exposure on metabolism of minerals. 4 colostomized and 10 intact broilers were exposed to 25~35℃ environmental temperature ,maintaining 35℃ for 3h each day. The other 10 intact birds were reared in a chamber with 20℃ constant temperature. The humidity was 50% in all treatments. After adaptative pereod of 8 days, the urine or total excreta of each bird were collected for 3 days to measure mineral excretion. Content of minerals in serum were analyzed. The results showed that: K concentrations in serum were reduced and Zn concentrations were increased by long term heat exposure, no significant change in contents of other minerals in serum(P>0 05). Under state of same intake, the total excrements of K, P, Mg, Na and Co of bird in high temperature environment were lower than control(p<0 05), and mineral excrements from urine had no significant diffrence between treatments.