| This study was conducted to research the effects of high temperatures on Jinjiangcattle in summer and preparate of anti-stress Chinese herbmedicine additives. All theexperiment were divided into three parts:(1)Study on the effect of Jinjiang cattle bodytemperature，serum hormone level and serum antioxidant level under summer hightemperature environment.(2)Study on the effect of different Chinese medicine anti-heatstress additives about cattle blood chemo-physiology index under high temperatureenvironment.(3)Study on the effect of different Chinese medicine anti-heat stressadditives about growth performance and nutrient digestibility of beef cattle under heatstress.The first experiment;To to investigate the changes of Jinjiang cattle bodytemperature，serum hormone level and serum antioxidant level under summer hightemperature environment, Nine eight-month-old Jinjiang cattle with an initial bodyweight of (210±20) kg were fed in spring (normal) and summer (heat stress periods). Thetrial period was divided into two stages: normal period for three days and heat stressperiod for60days. The results showed as follows:(1) The body temperature of cattle inheat stress periods increased significantly on1thand20thday, and then graduallyrecovered to normal on40thand60th.(2) Serum T3content of cattle in heat stressperiods are highly significant declined compared with the nomal on20d,40d and60d,however, serumT4levels had no significant difference in all stages;(3) Compared withthe nomal period, serum cortisol (COR) content was only increased significantly on20thday, and then gradually recovered to normal; the glucose (GLU) content of serum wasdecreased on60th day; the activities of serum total superoxide dismutase (T-SOD) werelower significantly on40thday, but the content of malondialdehyde (MDA) wereincreased significantly on20thand40thday. These results indicate that summer hightemperature and high humidity environment induce heat stress of beef cattle, and heatstress enhanced the rectal temperature and increase the content of COR, and decrease thecontents of T3and GLU. However, the rectal temperature and endocrine hormone contentof beef cattle would gradually recover to normal with the extension of heat stress time.The second experiment:This study was conducted to investigate the effect ofChinese medicine anti-heat Stress additives on growth performance and nutrientdigestibility of beef cattle under heat stress. Twenty-seven Jinjiang yellow cattle with eight month-old were randomly divided into3groups as following control group(Control), Chinese medicine addtive group1(CMA I) and Chinese medicine addtivegroup2(CMA II). Chinese medicine compound1and2were added by2%toconcentrate supplement diets of cattle in CMA I and CMA II. In each group, all cattlewere weight, and their nutrient apparent digestibilities were determined by the method ofwhole-collected feces at the end of the trail. Compared with the Control.(1)The resultsshowed that a significant enhance was noticed on the apparent digestion rate of OM(organic matter), CP (crude protein), CF (crude fiber) and ADF (acid detergent fiber) inthe CMA I.(2) The apparent digestion rate of CF and ADF in the CMA II were higherthan them of the Control.（3）After dietary supplementation with two Chinese medicinecompounds,the feed intake of the test cattle was no significantly difference, but the ADG(average dairy gain) was increased significantly, the FCR (feed conversion ratio) wasdecreased comparing to the Control. These results indicate that, dietary supplementationwith two Chinese medicine compounds enhanced the apparent digestion rate, andimproved the growth performance of cattle under heat stress.The third experiment: To study the effect of different anti-heat Stress Chinesemedicine additives on blood chemophysiology indexex of Jinjiang yellow cattle undersummer high temperatures. Twenty-seven JinJiang cattles with an initial weight of210kg,8month-old were randomly divided into three groups, Chinese medicine additivegroup I (CMA I) and Chinese medicine additive group II (CMA II), Controlgroup(Control). Chinese medicinal additives1and2were added for2%to theconcentrate feed of two Chinese medicinal additive groups. All experimental cattle werefed under summer high temperature environment. The results showed as follows:Compared to the control group;(1) The body temperature of cattle in CMA II groupwere decreased significantly but no difference in CMA I group; The cattle diarrhea statusof two Chinese medicine additive groups were significantly increased, with nosignificant difference between the two Chinese medicine additive groups;(2) Thecontents of serum thyroid hormone (T3and T4) in CMA I and CMA II were increased,and serum cortisol contents in CMA I were decreased by42.68%and17.05%on days40and60, there was no significant difference between the CMA II and Control;(3)MDAcontents of CMA I group were decreased, and T-SOD activity were increased. There wasa significant decrease in CMA II about MDA contents and T-SOD activity comparingwith the Control;(4) Compared to the control group, blood sugar levels of the two CMAgroups at20d was significantly reduced, the total protein, globulin levels in CMA II group were significantly increased; There are no difference about the activities of alanineaminotransferase, aspartate aminotransferase of CMA I and CMA II group. These resultsindicate that the diet supplemented with the two kind of Chinese additives can decreasedthe diarrhea fell of cattle under heat stress, help cattle body temperature graduallyreturned to normal, and improved their serum endocrine level and increased their serumantioxidant.According to the three test results, the high-temperature and high humidity inducedJinjiang cattle heat stress response, caused a negative impact on physiological andbiochemical indexes, and decreased nutrient digestibility and production performance ofjinjiang cattle. The diet supplemented with the two Chinese medicine compoundadditives alleviated cattle heat stress response and improved the production of beef cattleunder summer high temperatural environment. |
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