Department of Agroforestry Science and Technology and Genetics, Game and Livestock Resources Unit, University of Castilla-La Mancha, IDR, IREC, Albacete, Spain.
PLoS One. 2021 Apr 22;16(4):e0249540. doi: 10.1371/journal.pone.0249540. eCollection 2021.
Climatic models predict scenarios in which ambient temperature will continue increasing worldwide. Under these climatic conditions, fitness and animal welfare of many populations are expected to suffer, especially those that live in captive or semi-natural conditions, where opportunities of heat abatement are limited. We undertook an experimental design to assess the effect of heat abatement that water sprinkling might have on Iberian red deer calf growth and behaviour from birth to weaning (135 days). One group of ten mother-calf pairs lived on plots with water sprinkling (treatment) available during summer's hottest time of the day, while the control group (nine mother-calf pairs) occupied plots with no available water sprinkling. Treatment and control groups were fed ad libitum and swapped between plots every seven days to minimise any plot effect. Body weight was monitored weekly and individual behaviour was recorded once or twice a week at mid-day. We observed that calves had showers under the sprinklers and wallowed in mud puddles. The results clearly indicated that calves of the treatment group showed a significant increase in body weight at weaning in comparison with the control group, with no differences between sexes (treatment: male = 56.5 kg, female = 50.3 kg; control: male = 50.3 kg, female = 46.5 kg). Mother weight and mother age effects were negligible on calf body weight at weaning. The heavier the mother the faster was the rate of growth of its offspring, irrespective of calf sex. The model indicated that although males grew significantly slower than female calves in the control group, males grew faster than females when exposed to the treatment. Calves of the treatment group spent less time drinking, less time in the shade, similar time eating and more time in motion than calves of the control group. There were no behavioural differences between calf sexes of treatment and control groups. The results indicate the importance of providing animals with opportunities of heat abatement in hot environments to improve animal growth and welfare in farmed Iberian red deer.
气候模型预测，全球环境温度将持续升高。在这些气候条件下，许多种群的适应能力和动物福利预计将受到影响，尤其是那些生活在圈养或半自然环境中的种群，因为它们减少热量的机会有限。我们进行了一项实验设计，以评估在夏季最热的时间里，水喷淋对伊比利亚红鹿小牛生长和行为的影响，从出生到断奶（135 天）。一组十对母子在有喷淋水（处理）的地块中生活，而对照组（九对母子）则在没有喷淋水的地块中生活。处理组和对照组均自由采食，并每隔七天在地块之间交换一次，以尽量减少任何地块的影响。每周监测体重，每天中午记录一次或两次个体行为。我们观察到，小牛会在喷淋器下洗澡，并在泥坑中打滚。结果清楚地表明，与对照组相比，处理组小牛在断奶时体重明显增加，雌雄间无差异（处理组：雄性=56.5 公斤，雌性=50.3 公斤；对照组：雄性=50.3 公斤，雌性=46.5 公斤）。母鹿体重和母鹿年龄对断奶时小牛体重的影响可以忽略不计。母鹿越重，其后代的生长速度就越快，与小牛的性别无关。模型表明，尽管对照组雄性小牛的生长速度明显慢于雌性，但在暴露于处理组时，雄性的生长速度快于雌性。与对照组相比，处理组小牛的饮水时间减少，在阴凉处的时间减少，进食时间相似，运动时间增加。处理组和对照组小牛的性别之间没有行为差异。这些结果表明，在炎热的环境中为动物提供降温机会对于提高农场饲养的伊比利亚红鹿的生长和福利非常重要。
