Kamal Reena, Dutt Triveni, Patel Manjunath, Dey Amitava, Bharti Panch Kishore, Chandran Poolangulam Chinnakkan
Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, 243122, India.
ICAR Research Complex for Eastern Region, Patna, Bihar, 800014, India.
Trop Anim Health Prod. 2018 Apr;50(4):701-706. doi: 10.1007/s11250-018-1542-6. Epub 2018 Feb 13.
In tropical countries, at high temperatures, several physiological rearrangements occur in cows as they attempt to facilitate heat dissipation and/or reduce metabolic heat production. Following exposure to heat, cattle appear to acclimatize within 2-7 weeks. The failure of homeostasis at high temperatures may lead to reduced productivity or even death. The situation is even worse when humidity adds to high temperature. Livestock with elevated body temperature exhibit lower DMI and growth with less efficiency, reducing profitability for dairy farms in hot and humid climates. Shading of feed and water also offers production advantages. Although several elaborate methods for reducing heat stress in cows have been reported, simple shade materials appear to be the most cost-effective methods that are currently applicable to tropical developing countries. Different materials are being used to provide shade during warm weather. The shade material determines the microclimate-it should be light, strong, durable, weatherproof, good looking and a bad conductor of heat, and free from tendency to condense moisture inside. This review discusses various shade materials and their advantages and disadvantages in different situations.
在热带国家，高温时奶牛会出现一些生理调整，以促进散热和/或减少代谢产热。受热后，牛似乎在2至7周内适应环境。高温下体内平衡失调可能导致生产力下降甚至死亡。当湿度叠加高温时情况更糟。体温升高的家畜采食量和生长效率降低，降低了炎热潮湿气候下奶牛场的盈利能力。饲料和饮水的遮荫也有生产优势。尽管已报道了几种复杂的减轻奶牛热应激的方法，但简单的遮荫材料似乎是目前适用于热带发展中国家的最具成本效益的方法。温暖天气期间使用不同材料提供遮荫。遮荫材料决定小气候——它应质轻、坚固、耐用、防风雨、外观良好且是不良热导体，且无内部凝结水分的倾向。本文综述了各种遮荫材料及其在不同情况下的优缺点。
