The effect of different levels of dietary sorghum grain in finishing Ghezel×Arkhar-Merino crossbred lambs on performances and carcass characteristic

The aim of the present study was to investigate the effects of replacing dietary barely with different levels of sorghum on lamb performances. Sixteen Ghezel×Arkhar-Merino crossbred male lambs with live weights 46 ± 5.8 (mean ± SD) were used in the experiment. All dietary treatments had alfalfa hay (20% total DM), and remain part of diets (80% total DM) were contain different levels of barley and sorghum grain with different level of substitution. Lambs were randomly assigned to one of the four dietary treatments in a completely randomized design assignment, in which sorghum grain was used in the levels of 0, 60, 70 and 80 percent of total ration. Experimental diets were containing 0, 0.588, 0.686, and 0.784 percent of total tannin; respectively. The results of present experiment showed that different levels of dietary sorghum had significant effect on average weight gain of lambs (p<0.05) however it had no significant effect on dry mater intake and feed conversion ratio of lambs. Also dietary treatments couldnt affect total VFA, N-NH3 and pH of ruminal fluid and feces. Carcass characteristics such as hot and cold carcass weight, tail fat and dissectable fat weight affected by treatments (p<0.05). Using moderate level of sorghum grain along with barley grain in finishing lambs diet in a manner in which, dietary total taninn dont exceed 0.6 percent, showed the best results from stand point of performance and weight gain.