Estimation of carcass composition and fat depots by means of subcutaneous adipocyte area and body and tail measurements in fat-tailed Akkaraman lambs

Abstract

This study was conducted to establish prediction equations for subcutaneous adipocyte area and body and tail measurements to estimate carcass composition and fat depots of indigenous Akkaraman lambs. As a major carcass tissue, body fat depots play an important role in deciding the optimum slaughter weight and grading of the carcass and meat quality. In this respect, forty male Akkaraman lambs were slaughtered and dissected to define the partitioning of fat among body depots after recording the body and tail measurements and taking adipose tissue samples. Mean cold carcass weight was 19.8 kg with a composition of 48.9% muscle, 30.3% fat, 19.6% bone and 1.2% waste. The dressing percentage was 48.4 %. Tail fat, subcutaneous fat and intermuscular fat were the major fat depots with overall means of 15.3%, 10.2% and 4.9%, respectively. Heart girth had the highest correlation (r = 0.91) with total body fat, while tail circumference had the highest correlation (r = 0.72) with total body fat among the tail measurements. Correlation coefficients were also high between the adipocyte area and cold carcass (r = 0.84), total body fat (r = 0.84) and carcass fat (r = 0.86) values. The established regression equations showed that tail fat (R2 = 0.81), carcass fat (R2 = 0.89) and total body fat (R2 = 0.93) weights could be predicted with a high accuracy. It is concluded that carcass composition and body fat depots could be estimated with a high degree of accuracy by establishing the regression equations based on the adipocyte area and external measurements of the body and tail in Akkaraman lambs.

Keywords: Adipose tissue; carcass fat; regression; sheep

South African Journal of Animal Science Vol. 38 (4) 2008: pp. 282-289