Prediction of yield of saleable meat in beef carcasses.

Abstract

Proc. Aust. Soc. Anim. Prod. (1978) 12: 240 PREDICTION OF YIELD OF SALEABLE MEAT IN BEEF CARCASES R.J.W. GARTNER*, C.R. LUCKOCK** and G.W. BLIGHT* The Australian Meat Board is developing a beef carcase classification scheme which includes the measurements of carcase weight (CW) and fat depth (F) over the rib-eye muscle. Using these two measurements it may be possible to derive a prediction equation for the yield of saleable meat (YSM) from a carcase. The YSM was determined in 202 steers (primal cuts trimmed to about The cold CW included cod and channel 6 mm fat) using the whole carcase. fat and F was measured according to the Australian Meat Board (1971) scheme. The cattle orig.inated from nine experiments at Institute (ARI) and were finished either on roughage Although tests on pooling the nine equations showed ences (P( 0.01) in variances, slopes and intercepts, poses a combined equation was calculated: the Animal Research or high-grain diets. significant differfor practical pur; To assess the performance of the prediction equation, YSM values determined in 183 carcases entered in the Royal National Association . (RNA) carcase competition over six years were compared with values predicted using the AR1 equation (one side only used by RNA and CW was estimated as 97% hot weight). 1. The mean (range) for the two sets of data were: When predicted values of YSM for the RNA data were plotted against the observed values, a tendency to overestimate was apparent. However, this was mainly attributed to the data from one of the six years. The measure of performance used was the root mean squared difference. between the observed and predicted value (prediction standard deviation). It was calculated to be 7.93 (C-of V. 4.8%) compared with the value 5.99 (C. of V. 3.5%) found for the residual standard deviation (RSD) of the prediction equation. Both the AR1 and the RNA samples contained intensively finished young cattle. It is necessary to test the equation further, particularly in carcases from grass-finished cattle of both sexes. Australian Meat Board (1971). 'Australian Eeef Carcase Appraisal Systems'. (Offset Alpine Pty. Ltd. Sydney). * Queensland Department of Primary Industries, Animal Research Institute, Yeerongpilly, Queensland, 4105.' ** Australian Meat Board, Sydney, N.S.W. 240.