Feeding behavior of Angus and Chrolais-Angus Cows During Summer and Winter

Abstract

Two trials were conducted to determine differences in feeding behavior of Angus (A) and Charolais-Angus (C × A) crossbred cows. Observations in trial 1 were recorded on check sheets to determine percentage of time cows were grazing, resting-standing and resting-lying during daylight hours of 1 day each week for 6 weeks. Four groups, two of each breed-class and each containing 14 cows and nursing calves, were observed. The C × A cows rested less and grazed more than did A cows (P<.01), 57.4 vs 52.9% grazing time for C × A and A, respectively. The A cows spent 10% more daylight time resting-standing than did the C × A cows (P<.01). However, C × A cows were resting-lying 24.6% of the daylight hours as compared to 18.8% for the A cows (K.01). Grazing and resting activities were not signifiantly correlated with cow weight or calf gain. Automatic recording devices were used in trial II to determine periodicity of eating activity of 4 A and 4 C × A cows, selected from a total herd of 56 cows, fed ad libitum silage during winter and on summer pasture. Both breed-classes spent more time feeding in summer than in winter (P<.01), and C × A cows spent more time feeding than did A cows in both seasons (P<.05). Cows had night feeding periods in winter and summer lasting an average of 1 to 2 hours. The C × A cows' winter night grazing periods were longer than their summer periods and longer than the A cows' winter periods (P<.05). However, summer night grazing time was not significantly different for the 2 breed-classes. When breaks in activity of less than 5 min were disregarded, the C × A cows on summer pasture grazed an average of 9.0 hr per day, and A cows grazed 8.5 hr (P<.01). Copyright © 1976. American Society of Animal Science . Copyright 1976 by American Society of Animal Science