热应激对不同杂交组合肉牛生理指标和血液生化指标的影响

Effects of Heat Stresson Physiological Index and Blood Biochemical Index of Different Hybrid Beef Cattle

为探讨热应激对不同杂交组合肉牛生理指标和血液生化指标的影响我。本试验选择年龄、体况相近的红红本[红安格斯牛×(红安格斯牛×川南山地牛)]、红西本[红安格斯牛×(西门塔尔牛×川南山地牛)]、西西本[西门塔尔牛×(西门塔尔牛×川南山地牛)]和西红本[西门塔尔牛×(红安格斯牛×川南山地牛)]4个杂交组合肉牛,在夏季热应激条件下测定其直肠温度、脉搏、呼吸频率,并采集血样对其血液生化指标进行了测定和分析。结果表明:在热应激条件下4个杂交组合肉牛的直肠温度和心率差异不显著(P>0.05),红西本肉牛的呼吸频率显著低于西西本肉牛(P<0.05);在血液生化指标方面,红西本肉牛血清中的谷草转氨酶活性极显著低于西西本、西红本肉牛(P<0.01),肌酸激酶活性显著高于西红本肉牛(P<0.05);红西本肉牛血清中的T_3含量显著低于西西本、西红本肉牛(P<0.05),红细胞钾含量与西红本肉牛差异显著(P<0.05),血清K^+、Cl^-、Ca^(2+)含量在4个杂交组合肉牛间差异显著(P<0.05),其他血清生化指标含量在4个杂交组合间并没有显著差异(P>0.05)。结果显示,红西本肉牛具有较好的耐热性能。

In order to investigate the effects of heat stress on the physiological index and blood biochemical index of different hybrid beef cattle, four different hybrid beef cattle including Simmental×SimmentalxChuannan Mountainous （SSC）, Red AngusxRed AngusxChuannan Mountainous（RRC）, Sirnmentalx（Red AngusxChuannan Mountainous（SRC）, and Red Angus×Simmental×Chuannan Mountainous （RSC） with similar age and body condition were selected. Rectal temperature, heart rate and respiratory rate and blood biochemical indexes of beef cattle on heat stress were determined. The results indicated that rectal temperature and heart rate of four hybrid cattle were not significant （P〉 0.05）, while the respiratory rate of RSC was significantly lower than that of SSC. Glutamic oxaloacetic transaminase activity of RSC was significantly lower than that of SSC and SRC （P〈0.01）and its creatinekinase activity was significantly higher than that of SRC（P〈0.05）. T3 content of RSC was significantly lower than that of SSC and SRC（P〈 0.05）, and its potassium content in erythrocytes was significant compared with SRC （P〈0.05）. Moreover, there were significant differences （P〈0.05） in blood K^＋, Cl^- , Ca^2＋ and high density lipoprotein among the among four different hybrid cattle, while other blood biochemical index contents were not significantly different （P〉0.05）. Our results suggest that RSC has better resistance to effect of heat than other hybrid beef cattle.