This study was conducted to investigate the effect of the total digestible
nutrients (TDN) level of commercial concentrates on growth performance, carcass
characteristics, and meat composition of late fattening Hanwoo steers. A total
of 28 steers were randomly assigned to one of four dietary groups; T1
(73.30% TDN), T2 (74.50% TDN), T3 (76.40% TDN), and T4
(77.10% TDN). Average daily gain (ADG) was slightly but not significantly
higher in the T2 than in the other treatments. Dry matter intake (DMI) and feed
conversion ratio (FCR) were higher in the T2 than in the other treatments;
however, the differences were not statistically significant. Carcass back fat
thickness was thicker in the T4 and marbling score was higher in the T2 than in
the other treatments; however, the differences were not statistically
significant. The TDN level of concentrates had no effect on the physicochemical
characteristics and fatty acid composition of the
longissimus
muscle. The finding of this study indicate that less than 74% or greater
than 75% TDN in the commercial concentrate did not contribute to improve
ADG, FCR, marbling score; therefore, in the present study, the recommendable TDN
level in the commercial concentrate for late fattening period was 74% to
75% in terms of growth performance and marbling score of Hanwoo
steer.