Effect of a Simultaneous Increase in Crude Protein and Total Digestible Nutrients Contents on Late Fattening Hanwoo Steers

Background: Shortening the fattening period can reduce production costs and inedible fat, but may simultaneously negatively affect productivity and profitability. We hypothesized that increasing the crude protein and total digestible nutrients (TDN) in the formula feed could address the issues associated with shortened fattening periods without adversely affecting rumen fermentation. This study investigated the effect of a simultaneous increase of crude protein and TDN contents compared to conventional formula feed on growth performance, blood metabolites, carcass characteristics and meat composition of late fattening Hanwoo steers. Methods: Thirty Hanwoo steers were randomly assigned to one of two dietary groups: control group (16.4% crude protein and 83.6% TDN based on dry matter) and treatment group (17.4% crude protein and 84.6% TDN based on dry matter). Result: The rumen parameters were similar between the control and treatment groups. Likewise, the effect of additional crude protein and TDN contents in the formula feed showed no significant impact on the growth performance or blood metabolites. The carcass weight and yield index were slightly higher in the treatment group compared to the control, yet these differences were not statistically significant. Furthermore, the dietary treatment did not affect marbling score, meat color, fat color, texture, maturity, pH, surface colors, drip loss, cooking loss, sensory characteristics, or fatty acid composition in the longissimus muscle.