Abstract
Seventeen Japanese Black steers were used to examine the effects of finish weight (550kg, 600kg, 650kg), sires (2 groups) and concentrate during the latter fattening period (barley-fed group, corn-fed group) on carcass characteristics. During the growth of cattle from 550kg to 600kg, there was an increase of 18.4kg of muscle weight and 11.4kg of fat weight in the carcass. On the other hand, during the growth of cattle from 600kg to 650kg, there was an increase of 7.8kg of muscle weight and 25.2kg of fat weight in the carcass. Moreover, as the animals grew from 600kg to 650kg, there was a large increase in the fattening period and total TDN intake. These results suggest that it is more efficient to finish up to 600kg of live weight before the excess accumulation of fat in point of the growth rate and feed consumption. A significant effect of sires on the marbling score was obserbed. The barley fed group had larger muscle and bone weight than the corn fed group. There were significant interactions between sires and kinds of concentrate for slaughter age, total TDN intake, daily gain, cold carcass weight, dressing percentage, ribeye area and belly thickness except for the subcutaneous fat. The influence of the kinds of concentrate on feed intake, the rate of body weight gain and carcass characteristics changed for different sires.
