屋面喷淋通风降温系统对热应激肉牛血液生化指标的影响

探讨屋面喷淋通风降温系统对缓解南方夏季肉牛热应激的机理。选择健康状况良好、体质量相近的锦江黄牛16头,随机分为2组,每组8头牛,其中1组为室内通风组,2组为屋面喷淋通风降温组,测定肉牛血液生化指标、免疫指标和无机离子等相关参数。结果表明:与第1天相比,三碘甲状腺原氨酸(T3)含量,1组在试验第15天和31天分别降低5.68%和8.52%,2组在第15天和31天则分别提高了1.65%和5.49%;甲状腺原氨酸(T4)的含量,1组在试验第15天、31天差异不显著,2组在第31天时提高了14.48%(P0.05);皮质醇(COR)含量,1组差异不显著,但有上升趋势,2组则有下降趋势,且第31天与第1天相比差异极显著(P0.01);胰岛素生长因子(IGF-I)含量,1组第31天下降了4.93%,2组则提高了9.98%;血糖(GLU)含量,1组第15天和31天分别提高了2.30%和5.75%,2组分别提高了6.63%和19.83%;总蛋白(TP)、白蛋白(ALB)和球蛋白(GLO)含量,1组在第15天和31天均有所下降,2组TP、ALB、GLO均有所上升;免疫球蛋白M(Ig M)含量,1组均有所下降,2组上升显著;1组无机离子均有下降趋势,2组均有上升趋势,但差异不显著。以上结果表明:在南方夏季高温高湿气候下,通过屋面喷淋通风降温可有效改善肉牛机体的代谢紊乱,提高肉牛抵抗力。

Effect of Roof Sprinkling Ventilation and Cooling System on Blood Biochemical Indices of Beef Cattle in Heat Stress

In order to study the mechanism relieving heat stress with a roof sprinkling ventilation and cool?ing system,16 Jinjiang beef cattle were randomly divided into 2 groups. The environmental regulation form for Group 1 was interior ventilation.That of Group 2 was a roof sprinkling ventilation and cooling system.The blood biochemical indices,immune index and inorganic ion of the beef cattle were measured.The results showed that:Compared with those on the 1st day,the T3 content of Group 1 on the 15th day and 30th day reduced by 5.68%and 8.52%.While that of Group 2 on the 15th day and 30th day increased by 1.65% and 5.49%.T4 content of Group 1 showed no significant difference on the 15th and 31th day.While that of Group 2 on the 31st day increased by 14.48%(P<0.05).The COR content of Group 1 showed no significant difference,but showed a rising trend. The COR content of Group 2 showed a downward trend(P<0.01).The IGF?I content of Group 1 on the 31st day decreased by 4.93%.While that of Group 2 increased by 9.98%.The GLU content of Group 1 on the 15th day and 31st day increased by 2.30% and 5.75%,respectively.Meanwhile that of Group 2 increased by 6.63% and 19.83%.The TP,ALB and GLO contents of Group 1 declined on the 15th day and 30th day.While that of Group 2 increased.The IgM content of Group 1 decreased.While the IgM content of Group 2 increased significantly. The inorganic ion content of Group 1 declined.The inorganic ion content of Group 2 showed a rising trend.But the difference was not significant.These results suggest that the metabolic disorder can be effectively improved and disease resistance of beef cattle can rise with the roof sprinkling ventilation and cooling system under high temperature and high humidity climate in summer in the south of China.