Effects of Reduced Crude Protein Level in Total Mixed Ration on the Growth Performance and Carcass Characteristics of Hanwoo Steers

Abstract

This study aimed to determine the effect of regulating crude protein (CP) levels in total mixed ration (TMR) on the growth performance and carcass characteristics of Hanwoo steers. The regimens were divided into a control group (TMR with 15% CP) and treatment group (TMR with 12.5% CP). The viable cell count and fermentation potential of the prepared experimental feed and the nutrient digestibility were evaluated. Growth performance and carcass characteristics were confirmed by evaluating the weight and intake of Hanwoo steers, and an economic analysis was performed. Only CP digestibility was higher in the control group than in the treatment group (p0.05). There were no significant differences in carcass weight, yield index, back fat thickness, and loin area (p>0.05), but the appearance rate of quality grade A was higher in the treatment group than in the control group. In addition, there was no difference in the meat quality characteristics, such as marbling, meat color, fat color, texture, and maturity (p>0.05), and the treatment group had a higher rate of 1++ grade than the control group. Economic analysis showed that when 10 cattle were shipped, the control group received a price of 100,041 thousand won, and the treatment group received a price of 102,033 thousand won. When the income for each group was calculated, the production cost of the treatment group was 8% lower than that of the control group; thus, a higher net profit could be expected considering the low feed cost. Therefore, the economic feasibility of steer raising could be improved while maintaining productivity by controlling CP levels in feed. In addition, this study provides useful basic data for precisely adjusting the CP levels in feed for Hanwoo steers.