The aim of the present study was to test a possible way of statistical checking of the measurement uncertainty in pig carcass classification; i.e. to monitor deviations between operators when measuring fat and muscle thickness used for meat percentage calculation. For that purpose, data were obtained from the official classification body Bureau Veritas for the year 2009, which comprised eight operators working in five abattoirs. An analysis of covariance was performed using a model with the effects of the operator, carcass weight as a covariate and their interaction. The equality of the regression lines (regression coefficients and intercepts) was tested for various operators. Regression lines differed significantly between the operators, however all pairwise comparisons were not conclusive since the operators work only in one or two abattoirs, the abattoirs have different suppliers i.e. different origin of pigs. In order to differentiate between the operator and the abattoir effect we further compared i) different operators working in the same abattoir and ii) same operator working in different abattoirs. The deviations in measurements of muscle and fat (often reflected also in meat percentage) were more important in the case of the same operator working in different abattoirs, than in the case of different operators working in the same abattoir.

pig; carcass classification; operator; uncertainty; statistical control

Published by University of Zagreb, Faculty of Agriculture, Zagreb, CROATIA
Sponsored by Ministry Science and Education of the Republic of Croatia