The evaluation of automatic probes in Spain for the new scheme for pig carcass grading according to the EC regulations

Abstract

An evaluation of three automatic recording probes, the Fat-o-Meater (FOM), the Hennessy Grading Probe II (HGP) and the Destron PG-100 (DST) was carried out for use in the revised European Community (EC) Pig Grading Scheme. One hundred and forty-five pig carcasses were selected from four abattoirs covering the national fatness distribution. Two fat thickness depths, one at the head of the last rib (LR) and the other at the 3rd/4th from the last rib (3/4LR fat), and one muscle depth (3/4LR muscle) taken in the same operation for recording 34LR fat were studied as predictors of EC reference lean concentration. All measurements were taken 60 mm from the dorsal mid line. The corresponding cut surface measurements were also recorded and the carcasses were dissected. The prediction of cut surface fat depths from fat depth probes was better than the prediction of cut surface muscle depth from muscle depth taken with the probes. The DST fat measurement predicted more accurately the corresponding cut surface measurements and FOM muscle depth was more precise in predicting muscle cut surface depth. The DST was better in the prediction of EC reference lean concentration with 3/4LR fat and 3/4LR muscle as predictors (residual s.d. 23·1 g/kg). By adding LR as a third independent variable FOM predicted slightly better the lean concentration (residual s.d. 22·3). For Spain, the equations with these three independent variables were submitted to the Pig Management Committee of the EC. All the methods tested predicted EC reference lean concentration with a residual s.d. less than 25 g/kg and a correlation higher than 0·8.