Feedlot performance of Brahman X Angus versus Angus steers during cold weather
1991
Boyles, S.L. | Riley, J.G.
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 16 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 < .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 < .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 < .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 < .05) and longer from first rib to aitch bone (P < .05) and from thoracic vertebrae (T12/T13) to point of hock (P < .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. In vitro gas production measurements were not significantly different. Therefore, differences in performance may not be due to ruminal function. Serum thyroxine levels tended to be higher in winter than in spring or summer, but breed effects were not significant.
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