缓解奶牛热应激的喷淋水滴粒径研究

发布时间：2018-06-23 02:55

  本文选题：奶牛 + 喷淋水滴粒径　； 参考：《农业机械学报》2017年09期

【摘要】：为探讨夏季缓解奶牛热应激喷淋水滴粒径对降温效果的影响,通过现场实验测试了3种平均喷淋水滴粒径(0.829、0.947、1.127 mm)缓解奶牛热应激效果。实验中利用热像仪采集奶牛体表温度,同时测定呼吸频率、直肠温度生理指标,并在此基础上利用Merkel焓差理论分析计算奶牛喷淋降温换热量。结果表明,喷淋过程中,3种粒径(0.829、0.947、1.127 mm)在奶牛脖颈区域平均降温为0.7、1.1、0.9℃,腹部区域平均降温为0.7、1.4、1.5℃,平均呼吸频率分别降低0.6、4.2、2.1次/min;喷淋结束后,3种粒径在奶牛脖颈区域平均降温为0.2、0.4、0.6℃,腹部区域平均降温为0.1、0.5、0.6℃,平均呼吸频率降低-0.4、1.4、1.2次/min。喷淋前后奶牛直肠温度均控制在稳定范围内,且平均喷淋水滴粒径0.947 mm和1.127 mm低于0.829 mm时的奶牛平均直肠温度。3种平均喷淋水滴粒径对应的奶牛单位时间换热量分别为417.4、469.9、430.4 W,其中0.947 mm平均喷淋水滴粒径下换热量最大。因此,平均喷淋水滴粒径0.947 mm更适用于夏季奶牛喷淋降温。
[Abstract]:In order to investigate the effect of sprinkling water droplet size on cooling effect in summer, three kinds of average spray water droplets diameter (0.829 ~ 0.947 ~ 1.127 mm) were tested in the field. In the experiment, the body surface temperature of dairy cattle was collected by thermal imager, and the physiological indexes of respiratory frequency and rectal temperature were measured simultaneously, and based on this, the heat transfer was calculated by using the theory of Merkel's enthalpy difference. The results showed that during the spraying, the average temperature of the three diameters (0.829, 0.9471.127mm) in the neck area of dairy cattle was 0.71.1kW 0.9 鈩，

本文编号：2055436