Effect of Indigenous Herbs on Growth, Blood Metabolites and Carcass Characteristics in the Late Fattening Period of Hanwoo Steers

This study was conducted to evaluate the effects of indigenous herbal supplements on growth, blood metabolites and carcass characteristics in the late fattening period of Hanwoo steers. In a 6 month feeding trial, thirty Hanwoo steers ($647{\pm}32$ kg) were allotted to one of 5 treatment groups, control (basal diet contained lasalocid), licorice, clove, turmeric and silymarin, with six steers per pen. All groups received ad libitum concentrate and 1 kg rice straw/animal/d throughout the feeding trial. Blood samples were collected at the beginning, middle, and the end of the experiment and the steers were slaughtered at the end. Blood glucose, triglyceride, total protein, and albumin concentrations were higher in the turmeric treatment compared with other treatments. Blood urea nitrogen and creatinine concentrations were highest (p<0.003 and p = 0.071, respectively) in steers treated with silymarin. Alanine aminotransferase activity was lower (p<0.06) for licorice and silymarin compared with the control group. There were no alterations in serum aspartate aminotransferase and gamma glutamyltransferase activities as a consequence of herb treatments (p = 0.203 and 0.135, respectively). Final body weight, body weight gain, average dairy gain and dry matter intake were not significantly different among treatments. Yield grade, marbling score and quality grade were higher for silymarin group than those of the control group (p<0.05). Therefore, the results suggest that silymarin can be used an effective dietary supplement as an alternative to antibiotic feed additive and a productivity enhancer, providing safe and more consumer acceptable alternative to synthetic compounds during the late fattening period of steers.