Effects of Roughage Levels on Growth, Beef Quality, Ruminal Contents and Serum Constituents in Japanese Black Steers during the Growing Period

Abstract

The effects of roughage levels on growth, beef quality, ruminal contents and serum constituents during the growing period in Japanese Black steers were investigated. Eight Japanese Black male calves, which were 4 months old, were divided into two groups: a high roughage group (H) and a low roughage group (L). The animals in H and L were fed a diet containing approximately 60% and 30% roughage on TDN basis respectively during the growing period (4 to 10 months old). They were fed the same diet in the fattening stage (11 to 30 months old). The average daily gain in L was greater than that in H during the growing period. The withers height and heart girth, however, were similar in both groups throughout this study. The body weights at the end of fattening period were also similar in both groups. The beef marbling in H was better than that in L, but not significantly. The intermuscular fat thickness in H was significantly thinner than that in L. These results suggest that feeding a large quantity of roughage during the growing period gives a preferable carcass for meat industry with relatively small amount of intermuscular fat.