Department of Animal Sciences and Industry, Kansas State University, Manhattan 66502, USA.
J Dairy Sci. 2011 Feb;94(2):1026-31. doi: 10.3168/jds.2010-3126.
Two experiments were conducted on a commercial dairy farm in eastern Saudi Arabia to investigate the effects of Korral Kool (KK; Korral Kool Inc., Mesa, AZ) cattle cooling systems complemented with feedline soakers on core body temperature (CBT) of dairy cows. In both experiments, cows had access to KK 24h/d. In the first experiment, 7 primiparous and 6 multiparous lactating Holstein dairy cows were assigned to 1 of 2 pens, which were assigned randomly to treatment sequence over 4 d in a switchback design. Soakers were on (ON24) or off (OFF24) for 24h/d. For the second experiment, 20 multiparous lactating Holstein cows were assigned randomly to 1 of 2 pens, which were assigned randomly to treatment sequence in a switchback design. This experiment lasted 4 d and feedline soakers alternately remained off or were on (ON12) for 12h/d. In experiment 1, average ambient temperature was 30 ± 0.9°C and average relative humidity was 44 ± 14% (mean ± SD). Feedline soakers complementing KK systems for 24 h/d decreased the mean CBT of lactating dairy cows compared with KK systems alone (38.80 vs. 38.98 ± 0.061°C, respectively). A significant treatment by time interaction was found. The greatest treatment effects occurred at 2100 h; treatment means at this time were 39.26 and 38.85 ± 0.085°C for OFF24 and ON24 treatments, respectively. In experiment 2, average ambient temperature was 35 ± 1.5°C and average relative humidity was 33 ± 16%. Feedline soakers running for 12 h/d significantly decreased the mean 24-h CBT from 39.16 to 38.99 ± 0.084°C. Treatment by time interaction was also significant; the greatest treatment effects occurred at 1500 h, when ON12 reduced CBT from 39.38 to 38.81 ± 0.088°C. These results demonstrate that complementing the KK system with feedline soakers decreased the CBT of dairy cows housed in desert environments. However, the combined systems were not sufficient to lower CBT to normal temperatures in this extreme environment.
在沙特阿拉伯东部的一个商业奶牛场进行了两项实验，以研究 Korral Kool（KK；Korral Kool Inc.，Mesa，AZ）牛冷却系统与饲料线喷淋器相结合对奶牛核心体温（CBT）的影响。在这两项实验中，奶牛都可以 24 小时使用 KK。在第一项实验中，将 7 头初产和 6 头经产泌乳荷斯坦奶牛分配到 2 个围栏中的 1 个，每个围栏在 4 天的折返设计中随机分配到处理顺序。喷淋器每天 24 小时开（ON24）或关（OFF24）。在第二项实验中，将 20 头经产泌乳荷斯坦奶牛随机分配到 2 个围栏中的 1 个，每个围栏在折返设计中随机分配到处理顺序。这个实验持续了 4 天，饲料线喷淋器每隔一天交替开（ON12）或关（OFF12），每天 12 小时。在实验 1 中，平均环境温度为 30±0.9°C，平均相对湿度为 44±14%（平均值±标准差）。KK 系统补充使用 24 小时的饲料线喷淋器可降低泌乳奶牛的平均 CBT，与单独使用 KK 系统相比（分别为 38.80 与 38.98±0.061°C）。发现处理与时间之间存在显著的交互作用。最大的处理效果发生在 2100 小时；此时 OFF24 和 ON24 处理的平均处理值分别为 39.26 和 38.85±0.085°C。在实验 2 中，平均环境温度为 35±1.5°C，平均相对湿度为 33±16%。每天运行 12 小时的饲料线喷淋器可显著降低 24 小时平均 CBT，从 39.16 降至 38.99±0.084°C。处理与时间的交互作用也很显著；最大的处理效果发生在 1500 小时，此时 ON12 将 CBT 从 39.38 降至 38.81±0.088°C。这些结果表明，在沙漠环境中，用饲料线喷淋器补充 KK 系统可降低奶牛的 CBT。然而，在这种极端环境中，联合系统还不足以将 CBT 降低到正常温度。
