Abstract

Eye muscle dimensions of meat and fat together with live or carcass weight are important selection criteria for the improvement of carcass traits in sheep. The use of B-mode ultrasound may offer scope for more efficient progeny testing procedures. Two trials examined the use of ultrasound for estimating eye muscle width (A) and depth (B) between the twelfth and thirteenth ribs on live animals, and their carcasses immediately following slaughter and up to nine hours later. These estimates were then compared with ruler measurements on the eye muscle cut surfaces. Correlations between the various estimates of B were high (r = 0.80 to 0.96). While the correlation between the live scan of A and its ruler measurement was 0.75, the correlations between carcass scans and ruler measurements were 0.40 to 0.61. This was due to difficulty in maintaining acoustic coupling over the length of the probe, which was flat relative to the curved carcass surface. A new curved offset offers excellent prospects for overcoming this problem.

NJ, Edwards, and WJ Parker

Proceedings of the New Zealand Society of Animal Production, Volume 55, , 67-69, 1995