Mechanism Of Anti-Heat Stress Herbs Additive

This experiment was designed to study the mechanism of heat stress on pigs, and discuss the role&mechanism of anti-heat stress herbs by observing the influence on productive performance, serum biochemical indexes & endocrine hormones, and so on, so as to offer some theory basis on alleviating heat stress and farther developing anti-heat stress herbs with low poison and side-effect, convenient and remarkable benefit.The experiment used single factor trial design. 36 piglets, about 10kg weight, divided into two groups stochasticly, with three replications per group and 6 piglets per replication. The trial groups fed on basal diet with one percent anti-heat stress herbs. After 80 days, productive performance, serum biochemical & immunological indexes, endocrine hormones were investigated. The results showed: Under high temperature circumstance, (1 ) Anti-heat stress herbs could improve the productive performance of pigs. In 20~50kg phase, comparing to the control group, the ADG of the trial group improved 11.3 percent, the ADFI increased 90g and rised 5.5 percent, the average weight enhanced 3.2kg and increased 5.7 percent, but the FCR failed 5.2 percent. (2) Comparing to the control group, the content of GLU, CHO and TG3 of the trial group descended during the whole experiment. In 20~50kg phase, the GLU of trial group decreased significantly (P<0.01 ) ,the TG3 of trial group decreased significantly during the whole experiment (P<0.05) .However, anti-heat stress herbs couldn't affect significantly the metabolize of proteins. (3 ) Anti-heat stress herbs could affect the endocrine system in a certain extent. In 10~20kg phase, the content of FT3 and FT4 of trial group had little change, but the content of serum ACTH and Cor of trial group descended significantly (P<0.01) .their ratio improved dramatically (P<0.01) .In addition, the content of serum ALD decreased significantly (PO.05) .In 20~50kg phase, the content of FT3 and FT4 of trial group climbed significantly compared with control group (P<0.05) ,the content of serum ACTH and ALD of trial group descended significantly ( P<0.05) ,the content of Cor increased clearly (P<0.01 ) . (4) During the whole experiment, the serum enzymes of trial group had great changes, the content of all enzymes besides ALKP decreased significantly compared with control group. In 10~20kg phase, the content of serum ALT, AST of trial group failed clearly ( P<0.01 ) ,in 20~50kg phase, the content of serum ALT of trial group decreased significantly ( P<0.01 ) ,but their ratio had little change in the twophages. During the whole experiment, the level of serum CK of trial group decreased significantly(P<0.01) ,but the level of serum ALKP enhanced clearly (P<0.05) . (5) Compared with controlgroup, in 10~20kg phage, the content of IgG, C4 of trial group increased obviously (P<0.05) , thecontent of C3, IL-2 of trial group enhanced significantly (P<0.05) ,the quantity of RBC and thepercentage of LYM of trial group increased clearly (P<0.05) .In 20~50kg phage, the content of IgG,C4, C3 of trial group increased reluctancly (P<0.1 ) ,but the content of IL-2 enhanced significantly(P<0.05).(6)Duringthe whole experiment, the anti-heat stress herbs had some effect on serum K+,Na+, Cl-, Ca2+ of testing pigs, but not significantly.In conclusion, the results indicated that the mechanism of anti-heat stress herbs is to regulate the hypothalamic-pituitory-adrenal axis, the hypothalamic-pituitory-thyroid axis and the system of endocrine & immunity, so as to elevate the heat-resistant ability of testing pigs and alleviate the bad effect of high temperature on pigs.