LEVELS OF PROTEIN AND FAT AND TYPE OF PROTEIN IN VEALER RATIONS

Abstract

Three levels of crude protein 13.2, 15.4 and 17.7%, three levels of tallow 0, 3 and 6% and two sources of protein, meat and bone meal (MBM) and soybean meal (SBM) were compared in 3 × 3 × 2 factorial design using 216 Holstein type male calves. The calves were weaned at 3 wk of age and slaughtered at 113 kg liveweight. Twenty-four control calves were fed whole milk at 12% of body weight. Fat levels in the concentrate did not affect the age at slaughter but the 17.7% protein level decreased market age compared with the 13.2% protein diet from 131 days to 120 days and decreased total concentrate consumption by 25.7 kg. MBM gave paler carcasses as determined by reflectance than SBM as the supplementary protein source. The milk-fed calves were slaughtered at 102 days of age compared to an average of 126 days for the concentrate-fed calves; the respective daily gains, carcass yields, and muscle color scores were 0.72 and 0.55 kg; 56.5 and 50.5%; 58.8 and 48.4. Tallow was not utilized efficiently as an energy source by the young calf and MBM can replace completely SBM in concentrate for veal calves. A level of protein of 13.2% in the concentrate produced lower, but comparable, performance than did 17.7% protein.