PASTURE REARING AND MILK-REPLACER FEEDING OF DAIRY CALVES
Ayrshire bull calves were utilized in two feeding trials with the following treatments in factorial design: indoors vs. pasture, whole milk vs. milk-replacer, 3 or 4 lb starter daily to 15 weeks of age in the first trial and 2 or 3 lb in the second. All calves received the same treatment after 15 weeks, fall pasture and winter drylot.The average daily body weight gain from 1 week of age to weaning at 130 ± 2 lb was 1.05 lb and did not differ appreciably among treatments. Starter intake was increased markedly by indoor and (or) milk-replacer feeding. Calves receiving milk-replacer indoors consumed an average of 1 lb starter per day; calves fed whole milk on pasture ate only 0.4 lb starter per day. Weight gains from weaning to 15 weeks of age on pasture were 1.5 lb/day for calves weaned from whole milk, and 1.2 lb/day for those previously fed milk-replacer. Starter levels had little effect on the performance of the pasture — whole milk group. Indoor rearing compared with pasture rearing during this period significantly decreased calf gains, the greatest reduction occurring from milk-replacer and (or) low starter level. Calf performance to 1 year of age did not differ as a result of preweaning liquid diet, starter levels, and in the first trial initial rearing environment (1.4 lb/day). The 2-lb starter level significantly decreased yearly gains for calves initially reared indoors compared with pasture.