Sources of carbohydrates in the ingestive behavior of feedlot steers

In this article we research the influence of different sources of carbohydrates (corn, soybean hulls or wheat bran) upon the digestive behavior of 24 confined castrated steers with an initial average age and weight of 20 months and 330 kg born from the cross between Charolais and Nellore. The diet was composed of 40% sorghum silage and 60% concentrate. The time spent on total ruminating (an average of 454.6 min/day) was not influenced by the source of carbohydrate. The animals from the wheat bran treatment spent less time idle (718 min) in relation to those on the corn and soybean hulls treatments, which did not differ between themselves (an average of 792 min/day). The steers from the wheat bran treatment remained less time feeding (184 min/day) compared with those fed the other treatments, whose average time of permanence in this activity was 214 minutes per day. The other studied variables did not present a significant difference between the treatments. Inclusion of wheat bran in the diet of the confined steers results in less spent time idle, while steers feeding on soybean hulls spend less time feeding. The use of corn, soybean hulls, or wheat bran in the diet of the confined steers does not affect the total cudding time.

本研究探讨不同碳水化合物来源（玉米、大豆皮或麦麸）对24头舍饲阉割公牛消化行为的影响。试验牛初始平均月龄为20月龄，初始平均体重330kg，均为夏洛莱牛(Charolais)与内洛尔牛(Nellore)的杂交后代。试验日粮由40%高粱青贮料与60%精饲料组成。总反刍时长（日均454.6分钟）不受碳水化合物来源的影响。麦麸饲喂组试验牛的空闲时长（日均718分钟）显著低于玉米组与大豆皮组，而后两组的空闲时长无显著差异（日均792分钟）。麦麸饲喂组试验牛的采食时长（日均184分钟）显著短于其余各组，其余各组的日均采食时长均值为214分钟。其余观测指标在各组间均无显著差异。在舍饲公牛日粮中添加麦麸可降低其空闲时长，而饲喂大豆皮的公牛采食时长更短。在舍饲公牛日粮中使用玉米、大豆皮或麦麸，均不会对总反刍时长产生影响。