Fat distribution in steer carcasses of different breeds and crosses. 2. Distribution between joints

Abstract

SUMMARY: Dissection data for 643 steer carcasses of 15 breed-type × feeding system groups were used to examine the distribution of intermuscular fat (IF) and subcutaneous fat (SF) depots between standardized commercial joints.The increase in weight of IF and SF in each joint relative to the corresponding depot weight in the side was examined using the allometric equation. Pooled within-group growth coefficients for both IF and SF were lowest in the distal limb joints increasing inwards to the joints of the rib and loin regions. They were highest for the thin flank joint.Group means for weight of IF and SF in each joint were adjusted to equal total IF and SF weight respectively using the pooled growth coefficients. Statistically significant but relatively unimportant differences were recorded between groups in the adjusted means for all joints tested. The largest differences occurred for the top piece and were 0·39 and 0·40 kg (in one side) for IF and SF respectively. The stability of regression equations between groups for predicting the percentages of IF and SF in the side from the respective percentage in each joint was also examined. Joints which gave the least precise predictions of IF (shin and leg) and SF (shin, leg and clod and sticking) had the most unstable prediction equations. The equations for the other joints differed little between groups.