Effect of Feeding Sorghum Straw Based Complete Rations with Different Roughage to Concentrate Ratio on Growth and Carcass Characteristics in Nellore Ram Lambs

In order to find out the most suitable ratio of sorghum (Sorghum bicolor) straw: concentrate for optimum growth, production and carcass characteristics in Nellore ram lambs, a study was carried out by feeding sorghum straw based complete rations at the ratio of 70:30 (CR-I), 60:40 (CR-II), 50:50 (CR-III) and 40:60 (CR-IV) for 180d. The ADG was significantly (P<0.05) higher in CR-III and CR-V groups as compared to CR-I and CR-II. The FCR was lower (P<0.01) by 11.87, 16.91 and 22.54 per cent with CR-III, CR-II and CR-I rations, respectively, in comparison to CR-IV ration. The feed cost (H) per kg LW gain was significantly (P<0.01) higher in lambs fed CR-IV followed by CR-III, CR-II and was the lowest in CR-I. The dressing percentage expressed either on live or empty BW basis and per cent of leg, loin, rack, shoulder and neck and fore shank and brisket were similar (P>0.05) among the four groups; however, significant (P<0.01) difference was found among dietary groups in the lean, bone and fat contents of carcasses. Per cent weights of edible and non-edible organs and chemical composition of meat of the four experimental groups did not vary significantly. It is concluded that, inclusion of sorghum straw at 50–60% in the complete diets is considered to be economical in growing lamb's ration.