Comparision of feedlot performance and carcass characteristics of pure and crossbred of Lori-bakhtiari and Romanov lambs

The purpose of this study was to compare feedlot performance and carcass characteristics in Lori-bakhtiari and Romanov-Lori bakhtiari crossbred male lambs. In this opinion, 14 Lori bakhtiari and 14 Romanov- Lori bakhtiari male lambs were selected and their feedlot performance was studied in a completely random design during 100 days of trial. Lambs were fed by a total mixed ration (TMR) with forage to concentrate ratio of 30:70 in diets. Feed intake was recorded daily and the lambs were weighted monthly. At the end of the experiment, lambs were slaughtered and carcass analysis was done. The results of feedlot performances showed that crossbreeding had no significant effect on dry matter intake, final live weight, average daily gain and feed conversion ratio. Studying the carcass characteristics showed that crossbreeding had no significant effect on the warm carcass weight, empty rumen, lung and liver percent and carcass length (p>0.05), but the percent of heart, kidney and the internal fat weight were significantly affected by crossbreeding (p<0.05). The effect of genotype on the longissimus dorsi muscle area was significant also (p<0.05). Crossbreeding had a significant effect on the percentage of shank, round, brisket, flank and sirioin (P<0.05) and increased them. In general, although the effect of crossbreeding was not significant on the feedlot performance parameters, but improved the proportion of carcass components.