Sez. Ingegneria Agro-Ambientale - Facoltà di Agraria, Università Cattolica del Sacro Cuore, Piacenza, Italy.
Int J Biometeorol. 2012 Mar;56(2):287-95. doi: 10.1007/s00484-011-0432-7. Epub 2011 Apr 15.
This summer study aimed to evaluate the effect on dairy cows, kept in a free stall barn equipped with fans and sprinklers in the feeding area, of the delivery rate of misters in a cooling system in rest areas with different bedding materials. Thirty cows were divided into two homogenous groups according to milk yield and kept in two pens: one had beds with sand (SAMM) while the other had straw (STLM). Each pen was equipped with 2 fans (Ø 70 cm, 0.50 kW) and 2 misters (delivery rate of 11.2 and 22.5 L/h in STLM and SAMM, respectively) in the rest area. Microclimatic parameters, rectal temperature (RT), breathing rate (BR), milk yield, and some milk traits were recorded. Behavioural routines of the cows (standing and lying) were also continuously recorded during the hotter days. During the trial, two mild-moderate heat waves were observed. During these hotter periods, the daily maximum temperature recorded in the rest areas was 28.9 in SAMM and 31.2 in STLM, and the daily maximum THI was 78.2 in SAMM and 81.5 in STLM. In these periods, the cows in SAMM compared with those in STLM showed lower BR (P < 0.05) and greater rest time (10.2 and 7.8 h/day in SAMM and STLM, respectively). The RT did not differ (38.89 ± 0.29 and 38.88 ± 0.33°C in STLM and SAMM r,espectively). In conclusion, our research suggests that the cooling system using fans plus misters with mild wetting in rest areas with sand as bedding materials reduces heat stress and improves cow comfort.
本夏季研究旨在评估在配备风扇和喷淋器的自由卧床牛舍中，为不同卧床材料的休息区的降温系统中雾炮的输送率对奶牛的影响。30 头奶牛根据产奶量分为两组，并饲养在两个畜栏中：一个畜栏的卧床材料为沙子（SAMM），另一个畜栏的卧床材料为稻草（STLM）。每个畜栏在休息区配备 2 个风扇（Ø 70 cm，0.50 kW）和 2 个雾炮（在 STLM 和 SAMM 中的输送率分别为 11.2 和 22.5 L/h）。记录微气候参数、直肠温度（RT）、呼吸率（BR）、产奶量和一些牛奶特性。还连续记录了奶牛在较热天气下的行为常规（站立和躺卧）。在试验期间，观察到两次轻度至中度热浪。在这些较热的时期，休息区的日最高温度在 SAMM 中记录为 28.9，在 STLM 中记录为 31.2，日最高 THI 在 SAMM 中记录为 78.2，在 STLM 中记录为 81.5。在这些时期，与 STLM 相比，SAMM 中的奶牛的 BR 较低（P<0.05），休息时间更长（SAMM 和 STLM 中分别为 10.2 和 7.8 小时/天）。RT 没有差异（STLM 和 SAMM 中的 RT 分别为 38.89±0.29°C 和 38.88±0.33°C）。总之，我们的研究表明，在沙质卧床材料的休息区使用带轻度加湿的风扇加雾炮的冷却系统可减轻热应激并提高奶牛舒适度。
