Abstract

Given that almost all beef carcasses intended for export from New Zealand are boned out into cuts in the boning room of export plants, the feasibility was investigated of carrying the identification of individual animals from the point of slaughter through to sides in the boning room and using the weights (percentages) of selected cuts to predict the yield of saleable meat. A Ruakura beef cuts database with information from sides of 1461 bulls, 1097 steers, 320 heifers and 329 cows, all of known breeding, was used to test the accuracy of beef saleable meat yield prediction from the weights of three hindquarter cuts removed at the same time and site in the boning room. The inside round (topside), outside round (silverside) and thick flank expressed as a percentage of side weight were chosen for use alone and in multiple regression to predict the percentage of the carcass available as saleable meat. A model incorporating % inside and % outside and their interactions with sex (bull, steer, heifer and cow) provided useful prediction of % meat yield (R2 0.77, RSD 2.11%) and if hot carcass weight was added to the equation the R2 improved to 0.78 and the RSD was reduced to 2.06%. The sum of the inside and outside expressed as a percentage of side weight gave the same accuracy of prediction of percentage saleable meat yield as when they were treated as separate independent variables. The use of thick flank gave no improvement in prediction. These results should be compared with the present system where sex class, fat class (grade) and hot carcass weight predicted yield with an R2 of 0.60 and an RSD of 2.80% for the same set of data.

AH, Kirton, JJ Bass, BW Hogg, GJK Mercer, DM Duganzich, and EG Woods

Proceedings of the New Zealand Society of Animal Production, Volume 54, , 205-208, 1994