Effects of ractopamine hydrochloride on growth performance and carcass characteristics in wool and hair lambs

This study aimed at evaluating the effects of ractopamine hydrochloride (RAC) on growth performance and carcass characteristics of wool and hair lambs. For this purpose, 48 lambs averaging 31.3 kg body weight, of which twenty were wool (Ramboullet x Suffolk) and twenty eight were hair (Tabasco) lambs, and four levels of RAC (0, 10, 20, and 30 mg/kg diet, dry matter basis) were used. Wool lambs fed 20 and 30 mg RAC had higher (P<0.05) total gain weight and lower feed conversion than 0 and 10 mg RAC. Wool lambs fed 20 mg RAC had the highest carcass weight, dressing, legs weight and longissimus area as compared to 0, 10 and 30 mg RAC. In hair lambs there were not effect of RAC on growth performance and carcass characteristics. It was concluded that addition of RAC to finishing diets offered the best growth performance and carcass traits in wool lambs as compared to hair lambs.