Environmental factors affecting feed intake of steers in different housing systems in the summer
Environmental factors affecting feed intake of steers in different housing systems in the summer
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DOI：
10.1007/s00484-007-0136-1
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发表时间：
2008-07-01
影响因子：
3.2
通讯作者：
Hoffman, M. P.
中科院分区：
文献类型：
--
作者：
Koknaroglu, H.;Otles, Z.;Hoffman, M. P.
本研究从4月8日开始，10月3日结束，共使用了188头平均体重为299 kg的主要为安格斯和赫里福德品种的一岁阉牛，以评估环境因素对不同圈养系统中阉牛采食量的影响。住房包括有头顶遮蔽物的室外地块、没有头顶遮蔽物的室外地块和一个寒冷的封闭建筑。自由采食玉米、2.27 kg 35%干物质全株高粱青贮饲料和0.68 kg 61%蛋白质-维生素-矿物质补充剂。测量未消耗的饲料以确定饲料摄入量。温度数据由湿度-温度记录仪记录。每小时的温度和湿度被用来发展天气变量。采用回归分析，并对干物质摄入量（干物质）的天气变量进行回归。当添加新变量不能使R-2停止提高超过一个单位时，则截断模型中的变量数量。圈养牛的采食量低于开放式牧场和开放式牧场（P < 0.05）。牛在外面的地段，获得头顶上的庇护所有类似的发情期相比，在开放的地段（P=0.065）。热的影响主要表现在8月在三个住房系统。在解释的变化，在室外地段与头顶上的庇护所，平均和白天的温度是重要的因素，而在开放的地段，夜间，高峰和平均温度是重要的因素。在密闭建筑物中，前一天的温度和湿度指数是解释温度变化的最重要因素。结果表明，住房和天气变量的影响，在夏季，当考虑到这些结果，牛生产者希望提高牛饲养场的性能，应考虑住房条件提供更少的压力或更多的舒适。
A total of 188 yearling steers of predominantly Angus and Hereford breeds, with mean body weight of 299 kg, were used in this study, which started on 8 April and finished on 3 October, to assess the effects of environmental factors on feed intake of steers in various housing systems. Housing consisted of outside lots with access to overhead shelter, outside lots with no overhead shelter and a cold confinement building. Ad libitum corn, 2.27 kg of 35% dry matter whole plant sorghum silage and 0.68 kg of a 61% protein-vitamin-mineral supplement was offered. Feed that was not consumed was measured to determine feed intake. The temperature data were recorded by hygro-thermographs. Hourly temperatures and humidity were used to develop weather variables. Regression analysis was used and weather variables were regressed on dry matter intake (DMI). When addition of a new variable did not improve R-2 stop more than one unit, then the number of variables in the model was truncated. Cattle in confinement had lower DMI than those in open lots and those in open lots with access to an overhead shelter (P < 0.05). Cattle in outside lots with access to overhead shelter had similar DMI compared to those in open lots (P=0.065). Effect of heat was predominantly displayed in August in the three housing systems. In terms of explaining variation in DMI, in outside lots with access to overhead shelter, average and daytime temperatures were important factors, whereas in open lots, nocturnal, peak and average temperatures were important factors. In confinement buildings, the previous day's temperature and humidity index were the most important factors explaining variation in DMI. Results show the effect of housing and weather variables on DMI in summer and when considering these results, cattle producers wishing to improve cattle feedlot performance should consider housing conditions providing less stress or more comfort.