Abstract

Sheep Improvement Ltd. has a 'MEAT' Goal Trait Group which is used to select animals on their genetic merit for meat production. Breeding values are calculated for weight of carcass lean, carcass fat and carcass weight. These breeding values are estimated from live weight and ultrasonic eye muscle dimension data, with the option of incorporating computed tomography (CT) measurements. This served the sheep industry well while carcasses were graded on the basis of carcass weight and GR tissue depth. However, deregulation in the meat industry has seen individual meat processors developing carcass grading systems which not only improve estimates of lean and fat, but also estimate retail yield within individual cuts. SIL have developed a 'MEAT YIELD' module in response to these changes which estimates breeding values for lean weight in the shoulder, loin and hindleg primal cuts. Meat yield data collected from surplus slaughtered progeny are added to live weight and ultrasonic eye muscle data to predict the breeding values. Slaughter progeny should be randomly selected to avoid biasing the meat yield data. This module is likely to be developed further as additional grading systems are implemented, and equations to translate data into standardised measurements will be required.

NB, Jopson, S-AN Newman, and JC McEwan

Proceedings of the New Zealand Society of Animal Production, Volume 69, Christchurch, 161-164, 2009