Effect of the diet and genotype on body measurements and non-constituints of carcass of wooless lambs finished in a feedlot

Abstract

The objective of this study was to evaluate the body and carcass measurements, and non-constituents of carcass of wooless lambs, fed diets with two energetic levels. Eighteen lambs from genotype Morada Nova, Santa Inês and crossbred Dorper x Santa Inês were used. Diets with low and high energy content were composed of 2.5 Mcal EM/kg and 2.94 Mcal EM/kg MS, respectively. Body measurements used in the study were: withers height, height croup, body length, leg length, toracic perimeter, leg circunference, scrotal circunference, body score, body capability 1 (CC1) and body capability 2 (CC2). Non-constituents of carcass studied here were head weight, liver, heart, spleen, vesicle, blood, kidney, hooves, skin and lung + trachea. Moreover, traits of carcass were studied: carcass length, leg length, thigh perimeter, croup perimeter, thorax depth, toracic perimeter and chester width. Data were analized by model which included the effects of diets and genotype, beyond of the weigth as covariable. Diets affected (P<0,05) the body score and body capability (CC2). The genotype afeccted (P<0,05) the withers height, height croup, leg length, scrotal circunference, body score, body capability, CC1 and CC2. For carcass measurements the diet affected only the thoracic perimeter and chester width. The genotype affected the leg length, thigh perimeter and croup perimeter. Among the not carcass components, live, spleen, blood, hooves and skin were affected by the diets, while the genotype affected head, live, kidney and Hooves.