PRODUCTIVITY OF 2-YEAR-OLD CROSSBRED COWS PRODUCING 3-BREED CROSS CALVES

Production data from 2 yr old crossbred cows (434) and performance data to weaning from their 3-breed cross calves (334) were analyzed. Crossbred females were produced from 1973-1975 by matings of Hereford (H), Angus (A), Simmental (S), Brown Swiss (B) and Jersey (J) bulls to H and A cows. These 2 breed cross females were mated to Red Poll and Shorthorn bulls to produce their 1st calves at 2 yr of age. J cross and BA cows were most productive as 2 yr olds. J cross cows (90%) exposed to breeding weaned a calf while only 53% of the SH cows weaned calves. Heaviest calves (P < .05) at weaning were produced by BA cows (203 kg) and the lightest calves (P < .05) by HA reciprocal crosses (168 kg). J cross and BA cows were 47 kg (37.4%) more productive in terms of kg of calf weaned per cow exposed when compared to HA and AH cows. SH cows weaned 24 fewer kg of calf/cow exposed (19.7%) than HA reciprocal crosses. Individual cow efficiency measured by calf weaning weight divided by cow weight or cow metabolic weight favored J crosses by 18-20%, B crosses by 10-15% and S crosses by 0-5% over HA and AH cows. Lactational performance was measured on 2-yr-old crossbred cows (56) by machine milkout techniques. Daily milk yields were highest for B crosses (7.50 kg/day) and lowest (P < 0.05) for HA reciprocal cross cows (4.35 kg/day). Butterfat yields favored B and J crosses (0.268 kg/day) over S cross cows (0.214 kg/day) and HA reciprocal crosses (0.159 kg/day).