Boyles S L, Riley J G
Dept. of Anim. Sci., North Dakota State University, Fargo 58105.
J Anim Sci. 1991 Jul;69(7):2677-84. doi: 10.2527/1991.6972677x.
Ten Angus and 10 Brahman x Angus F1 steers were used in a 184-d trial to compare feedlot performance during cold weather (-9 to 26 degrees C). Both groups of steers were exposed to the same environment for the same amount of time. All steers were fed for the same number of days regardless of frame score to avoid frame score x environment interactions. Brahman x Angus steers were 30.7 kg heavier (P less than .05) than Angus steers at the start of the trial. Differences in age (Brahman x Angus 40 d younger) for the two breed groups did not affect final live weight or carcass weight. Brahman x Angus steers consumed .2% less feed (P less than .05) as a percentage of BW than Angus steers; however, there was no difference in overall feed efficiency. Angus steers had a higher yield grade, more fat at the 12th rib (P less than .05), and graded 90% Choice; only 10% of the Brahman x Angus were graded Choice. Brahman x Angus steers were taller at the hip (P less than .05) and longer from first rib to aitch bone (P less than .05) and from thoracic vertebrae (T12/T13) to point of hock (P less than .05). Hide thickness determined at the neck, belly, and rump was found to be similar (7.7 mm) between the two groups. Sample hair weight and diameter did not differ between groups. Fiber, fat, protein, and DM digestibility coefficients were similar between groups but Brahman x Angus feces had a higher DM content.(ABSTRACT TRUNCATED AT 250 WORDS)
选用10头安格斯阉牛和10头婆罗门牛×安格斯F1代阉牛进行了为期184天的试验,以比较寒冷天气(-9至26摄氏度)下的育肥性能。两组阉牛在相同环境下暴露相同时间。所有阉牛不论体格评分高低,饲喂天数相同,以避免体格评分×环境的相互作用。试验开始时,婆罗门牛×安格斯阉牛比安格斯阉牛重30.7千克(P<0.05)。两个品种组的年龄差异(婆罗门牛×安格斯牛小40天)不影响最终活重或胴体重。婆罗门牛×安格斯阉牛的采食量占体重的百分比比安格斯阉牛少0.2%(P<0.05);然而,总体饲料效率并无差异。安格斯阉牛的产肉等级更高,第12肋骨处脂肪更多(P<0.05),等级为90%的精选级;只有10%的婆罗门牛×安格斯阉牛为精选级。婆罗门牛×安格斯阉牛臀部更高(P<0.05),从第一肋骨到臀角骨更长(P<0.05),从胸椎(T12/T13)到跗关节点更长(P<0.05)。发现两组牛颈部、腹部和臀部的皮厚相似(7.7毫米)。两组间的毛样重量和直径无差异。两组间纤维、脂肪、蛋白质和干物质消化率系数相似,但婆罗门牛×安格斯阉牛的粪便干物质含量更高。(摘要截选至250词)