THE EFFECT OF BREED OF SIRE GROUP ON BEEF PRODUCTION AND CARCASS CHARACTERISTICS

Abstract

The effect of breed of sire on beef production and carcass characteristics was studied on 222 animals from nine separate trials. Nine breed of sire groups. Ayrshire, British (Angus, Hereford and Shorthorn combined), Burwash, Charolais, Chianina, Jersey, large dairy (Holstein and Brown Swiss combined), Limousin and Maine-Anjou, were represented. The criterion for slaughter for each animal was an average of 10.2 mm of fat cover at points 1/4, 1/2 and 3/4 of the distance along the longitudinal axis of the longissimus cross section at the 11th–12th rib junction as measured ultrasonically. Individual average daily gains to slaughter and total weights of feed for each experimental pen of animals were measured. Animals were slaughtered and dressed, and hot carcass weights recorded. After 48 h the left side of each carcass was cut into major wholesale cuts and each cut was physically separated into lean, bone and fat. Charolais and large dairy breed of sire groups had the highest average daily gains. No significant breed of sire effects were found for the ratio of estimated energy intake during the feeding period to weight of lean. The Maine-Anjou breed of sire group had the heaviest post-shrink liveweights. All carcass measurements were adjusted for differences in cold carcass weights and carcass backfat thicknesses. The Charolais breed of sire group had the heaviest adjusted weights of lean and hindquarters, the second lowest adjusted weights of fat and bone and the highest lean to bone ratios. The Chianina breed of sire group had the second highest adjusted weights of lean and hindquarters, the highest adjusted weights of bone and the lowest adjusted weights of fat. The Jersey breed of sire group had the heaviest adjusted weights of carcass fat and the lowest adjusted weights of hindquarters. It is important to note that the results of the Chianina, Maine-Anjou and Limousin breed of sire groups should be viewed with caution because of the small numbers of animals and sires represented.