Al-Tamimi Hosam, Al-Atiyat Raed, Al-Majali Ahmad, Alameri Omran
Department of Animal Production, College of Agriculture, Jordan University of Science & Technology, P.O. Box 3030, Irbid, 22110, Jordan.
Animal Production Department, College of Agriculture, Mutah University, Karak, Jordan.
Trop Anim Health Prod. 2019 Nov;51(8):2287-2295. doi: 10.1007/s11250-019-01948-5. Epub 2019 Jun 1.
We investigated the thermotolerance of the F1 progeny (Black Bedouin × Damascus crossbreed) to summer conditions alongside that of two pure breeds. Male goats (n = 7 per breed) were used to conduct a summertime 28-day trial along with hypohydration. The animals were fitted with miniscule thermologgers, intraperitoneally and subcutaneously, to measure core (T) and peripheral (T) body temperatures (BT), respectively. All goats were kept under shaded housing for a 7-day basal period before being switched to unshaded pens for the next 21 days. During the first 14 days, animals had free access to water. However, during the third 7-day period, access to water was time-restricted (4 h/day). Finally, it was restricted to 40% of the third week's average daily intake over the last 7 days. Exposure to the unshaded conditions resulted in pronounced heat stress in all animals, as reflected by 0.42 and 1.44 °C rises for T and T, respectively. The F1 goats displayed a clear heterothermic adaptive response, especially after the water restriction bouts' initiation. Interestingly, the F1 goats displayed higher ratios of renal relative medullary thickness (77.7, 73.3, and 72.6 ± 1.1%) along with higher circulating concentrations of antidiuretic hormone (44.6, 31.6, and 11.6 ± 3.7 ng/mL), respectively, which suggested an improved water metabolism.
我们研究了F1后代（黑贝都因×大马士革杂交种）与两个纯种山羊对夏季条件的耐热性。使用雄性山羊（每个品种n = 7只）进行为期28天的夏季试验并伴有轻度脱水。给动物腹腔内和皮下安装微型温度记录器，分别测量核心体温（Tc）和外周体温（Tp）。所有山羊在7天的基础期内饲养在有遮蔽的圈舍中，之后的21天转移到无遮蔽的围栏中。在最初的14天里，动物可自由饮水。然而，在第三个7天期间，饮水时间受到限制（每天4小时）。最后，在最后7天里，饮水量限制在第三周平均日摄入量的40%。暴露于无遮蔽条件下导致所有动物出现明显的热应激，Tc和Tp分别升高0.42℃和1.44℃。F1代山羊表现出明显的异温适应性反应，尤其是在开始限水后。有趣的是，F1代山羊的肾相对髓质厚度比例更高（分别为77.7%、73.3%和72.6±1.1%），同时抗利尿激素的循环浓度也更高（分别为44.6 ng/mL、31.6 ng/mL和11.6±3.7 ng/mL），这表明其水代谢得到改善。
