热应激对哺乳母牛免疫和繁殖机能的影响

Effects of Heat Stress on Immunity and Reproductive Function of Lactating Cows

[目的]为探究热应激对哺乳母牛免疫和繁殖机能的影响。[方法]2021—2022年在贵州省兴义市某奶牛场对不同气温环境下的40头哺乳母牛进行了检测。[结果]一年中牛舍夏季(6—8月)温度最高,与其他季节相比,该季节哺乳母牛血清中的血糖、尿素氮水平,免疫球蛋白G(IgG)、免疫球蛋白A(IgA)的含量显著降低(P<0.05),白细胞介素1β(IL-1β)和白细胞介素-6(IL-6)的含量显著升高(P<0.05);哺乳母牛的平均减重显著提高(P<0.05),平均采食量显著降低(P<0.05);哺乳母牛的发情间隔较其他时间段更长。[结论]在热应激条件下,哺乳母牛的免疫性能显著降低,繁殖机能也受到了负面影响,建议奶牛场在实际养殖过程中加大对哺乳母牛的关注,尤其是在夏季高温天气条件下,更应采用科学合理的饲养管理方法,以保障奶牛的健康生产。

[Objective]To explore the effects of heat stress on immune and reproductive function of lactating cows.[Method]From 2021 to 2022,40 lactating cows were tested in a dairy farm in Xingyi City,Guizhou Province.[Result]The temperature in cowshed is the highest in summer(June-August).Compared with other seasons,the blood sugar and urea nitrogen levels,immunoglobulin G(IgG)and immunoglobulin A(IgA)contents,interleukin 1β(IL-1β)and interleukin-6(IL-6)in serum of lactating cows in this season are significantly decreased(P<0.05).The average weight loss of lactating cows increased significantly(P<0.05),and the average feed intake decreased significantly(P<0.05).The estrus interval of lactating cows is longer than other time periods.[Conclusion]Under the condition of heat stress,the immune performance of lactating cows is significantly reduced,and the reproductive function is also negatively affected.It is suggested that dariy farms should pay more attention to lactating cows in the actual breeding process,especially in the high temperature weather in summer,and scientific and reasonable feeding management methods should be adopted to ensure the healthy production of dairy cows.