Effects of High Protein Diet on Meat Productivity and Quality in Multiparous Hanwoo Cull Cows

Multiparous Hanwoo cull cows have been generally regarded to have poor meat quality compared to young and primiparous Hanwoo in Korea, and there have been few studies attempting to understand various feeding programs for the multiparous Hanwoo cull cow. In this study, the effects of a feeding program consisting of two different diets for multiparous Hanwoo cull cows on meat production and quality were tested in comparison to a commercially used diet. Diets for treatment consisted of two levels of crude protein contents, 14.28% and 12.70% for early fattening and finishing, respectively. For a control, commercially used fattening feed (12.39% crude protein) was used. Feeding trials were performed at three different farms. In farm A, 29 herds of multiparous Hanwoo cull cows were used for the treatment group and 3 herds for the control. In farms B and C, the number of animal herds for treatment and control were 8 vs. 3 and 11 vs. 4 herds, respectively. Experiment diets were fed for an average of 211 days and in treatment, early fattening diet was fed for 4 months and then finishing feed was fed until slaughter. Average daily gains, thickness of back fat, area of Longissimus dorsi, carcass weight, index of carcass weight, intramuscular fat, meat color and texture were analyzed after slaughter. Random effect model [8] was employed in effect analysis. Positive effects of treatment were found in terms of average daily gain, back fat thickness, Longissimus dorsi area, carcass weight, and intramuscular fat. Carcass yield index, meat color and texture showed a negative effect. In this study, significant results were not found in all factors analyzed because the variance between experiment farms was large, however the 90% confidence interval of summary effects of ADG, back fat thickness, Longissimus dorsi area and carcass weight were significant and that of carcass yield index, intramuscular fat, meat color and texture were less so. Conclusively, a high protein diet fed early during the fattening period in multiparous Hanwoo cull cows could have positive effects on meat production.