Kang H J, Lee I K, Piao M Y, Gu M J, Yun C H, Kim H J, Kim K H, Baik M
Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea.
Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea ; Institute of Green Bio Science & Technology, Pyeongchang 232-196, Korea .
Asian-Australas J Anim Sci. 2016 Mar;29(3):436-43. doi: 10.5713/ajas.15.0937. Epub 2016 Mar 1.
Exposure to cold may affect growth performance in accordance with the metabolic and immunological activities of animals. We evaluated whether ambient temperature affects growth performance, blood metabolites, and immune cell populations in Korean cattle. Eighteen Korean cattle steers with a mean age of 10 months and a mean weight of 277 kg were used. All steers were fed a growing stage-concentrate diet at a rate of 1.5% of body weight and Timothy hay ad libitum for 8 weeks. Experimental period 1 (P1) was for four weeks from March 7 to April 3 and period 2 (P2) was four weeks from April 4 to May 1. Mean (8.7°C) and minimum (1.0°C) indoor ambient temperatures during P1 were lower (p<0.001) than those (13.0°C and 6.2°C, respectively) during P2. Daily dry matter feed intake in both the concentrate diet and forage groups was higher (p<0.001) during P2 than P1. Average daily weight gain was higher (p<0.001) during P2 (1.38 kg/d) than P1 (1.13 kg/d). Feed efficiency during P2 was higher (p = 0.015) than P1. Blood was collected three times; on March 7, April 4, and May 2. Nonesterified fatty acids (NEFA) were higher on March 7 than April 4 and May 2. Blood cortisol, glucose, and triglyceride concentrations did not differ among months. Blood CD4+, CD8+, and CD4+CD25+ T cell percentages were higher, while CD8+CD25+ T cell percentage was lower, during the colder month of March than during May, suggesting that ambient temperature affects blood T cell populations. In conclusion, colder ambient temperature decreased growth and feed efficiency in Korean cattle steers. The higher circulating NEFA concentrations observed in March compared to April suggest that lipolysis may occur at colder ambient temperatures to generate heat and maintain body temperature, resulting in lower feed efficiency in March.
暴露于寒冷环境可能会根据动物的代谢和免疫活动影响其生长性能。我们评估了环境温度是否会影响韩牛的生长性能、血液代谢物和免疫细胞群体。使用了18头平均年龄为10个月、平均体重为277千克的韩牛阉牛。所有阉牛均以体重1.5%的比例饲喂生长阶段浓缩饲料，并随意采食提摩西干草，持续8周。实验期1（P1）为3月7日至4月3日的四周，实验期2（P2）为4月4日至5月1日的四周。P1期间的室内平均环境温度（8.7°C）和最低环境温度（1.0°C）低于（p<0.001）P2期间的温度（分别为13.0°C和6.2°C）。P2期间浓缩饲料组和草料组的每日干物质采食量均高于（p<0.001）P1期间。P2期间的平均日增重高于（p<0.001）P1期间（1.38千克/天对1.13千克/天）。P2期间的饲料效率高于（p = 0.015）P1期间。在3月7日、4月4日和5月2日采集了三次血液。3月7日的非酯化脂肪酸（NEFA）含量高于4月4日和5月2日。血液皮质醇、葡萄糖和甘油三酯浓度在各月份之间没有差异。与5月相比，在较寒冷的3月，血液中CD4+、CD8+和CD4+CD25+ T细胞百分比更高，而CD8+CD25+ T细胞百分比更低，这表明环境温度会影响血液T细胞群体。总之，较低的环境温度会降低韩牛阉牛的生长和饲料效率。与4月相比，3月观察到的循环NEFA浓度较高，这表明在较低的环境温度下可能会发生脂肪分解以产生热量并维持体温，从而导致3月的饲料效率较低。
