Prediction of carcass composition by ultrasonic measurement and the effect of region and age on ultrasonic measurements

This study aimed to determine the relationship between age characteristics and sheep carcass composition with real time ultrasound. Data was collected from 34 Karayaka ewes and 20 female lambs. Skin and subcutaneous fat thickness, and muscle area, depth and width, were measured between the 12th and 13th thoracic vertebrae and 3rd and 4th lumbar vertebrae. The twenty female lambs were slaughtered to determine the muscle, bone and fat amount in their carcasses. The ultrasound measurements from the two regions were not significantly different (P > 0.05). It was also determined with ultrasound that the age of the animal had an effect on subcutaneous fat thickness and skin thickness (P < 0.05). In addition, there was a significant positive correlation among the ultrasound measurements in both regions with the carcass measured by dissection, and live weight. The coefficients of determination (R2) ranged from 0.76 to 0.99 in the multiple regression models for carcass composition using ultrasound. In conclusion, the present study suggests that the use of ultrasound skin thickness and muscle area and depth measurements, coupled with live weight, can be used to estimate carcass composition.