DIFFERENCES IN MARKET QUALITY BETWEEN BROILER STRAINS AS EVALUATED BY MARKET GRADING

Abstract

Chicks from 10 broiler strains were randomly allotted and reared at three farms. At 10 weeks of age a random sample consisting of 60 birds of each strain, with an equal number of each sex, was taken at each farm, slaughtered and market graded. At each farm, an official inspector graded the birds according to the standards of the Canada Department of Agriculture. Each bird was graded for the four grade factors: conformation, fleshing, fat and dressing.The number of birds in each grade class was not independent of farm, sex or strain. The 10 strains, ranked on grade scores, tended to rank in the same order at each farm, although the agreement was better for some grade factors than others, and was better when based on males than on females. On a strain rank basis, the grade scores for any one grade factor were not, in general, indicative of the scores for any other grade factor. Also on a strain rank basis, there was a high positive correlation between breast angle and grade scores for fleshing: body weight was not correlated with grade scores for any of the four grade factors, with the possible exception of conformation in the case of males.