Beef production from Holstein--Friesian, Norwegian Red X Holstein-Friesian and Jersey X Holstein-Friesian male cattle reared as bulls or steers

摘要

The Norwegian Red and Jersey dairy breeds have been evaluated for crossbreeding with Holstein-Friesian dairy cows in Ireland. If such crossbreeding becomes common practice, the resultant male calves will enter the beef industry. The objective was to compare production and carcass traits for Holstein-Friesian (HF), Norwegian Red x Holstein-Friesian (NR) and Jersey x Holstein-Friesian (JE) male cattle. A total of 120 spring-born male calves were reared to slaughter in a 3 breed types (HF, NR and JE) x two genders (bulls and steers) x 2 slaughter weights (Light, 570 kg and Heavy, 640 kg) factorial experiment. Following rearing indoors, the calves were at pasture for the first grazing season. Steers were castrated in September. The calves were housed for the first winter in October and offered grass silage ad libitum plus 1.5 kg/day concentrates. They returned to pasture in April for their second grazing season. The bulls were housed in August and the steers were housed in November. Both genders were finished on a total mixed ration of proportionately 0.67 concentrates and 0.33 silage (dry matter basis). Routine slaughter data were collected. The ribs joint was dissected into its components. Across gender and slaughter weight groups, slaughter weights per day of age were 836, 828 and 761 (s.e. 12.2) g for HF, NR and JE, respectively. Corresponding carcass weights and kill-out proportions were 314, 309 and 277 (s.e. 5.2) kg, and 495, 499 and 485 (s.e. 2.9) g/kg, respectively. Carcass conformation class (15-point scale) was 4.7, 53 and 4.0 (s.e. 0.23) for HF, NR and JE, respectively. Carcass fat class (15-point scale) was 8.5, 8.6 and 7.7 (s.e. 0.26) for HF, NR and JE, respectively. Feed intake during finishing was similar for the breed types, but intake per kg mean live weight was higher for JE. Slaughter weight per day of age was greater for bulls than steers and for Heavy than Light slaughter weight Bulls had higher kill out proportions, better carcass conformation, greater M. longissimus area and a greater proportion of ribs joint muscle, and a lower proportion of fat than steers. There were few important interactions. It is concluded that crossbreeding with NR had no negative effects on the beef merit of the male progeny compared with pure Holstein-Friesian but crossbreeding with JE reduced carcass weight and value per kg. (C) 2015 Elsevier B.V. All rights reserved.