A Relational Study of Gait Score (As a Measure for Lameness) With Breast Muscle Yield in Broiler Chickens

Abstract

A fast genetic change, developments in the feed and the management of the broiler chicken during the last 50 years led to an improved efficiency of broiler meat production. However due to the fast growth rates and inactivity of the chickens there is also a growing rate in occurrence in metabolic and locomotion problems One of the reasons of locomotion or gait problems may be due to the fact that the skeleton structure cannot support the 3 dimensional distribution of body weight of the animal, especially the genetically increased mass of the breast muscle. Therefore this study focuses on the relation of gait score as a measure of lameness with breast muscle weight of individual chickens. For these reason 124 39 days old broiler chickens were slaughtered and their breast muscle were dissected and weighed. The chickens prior to slaughtering were also manually scored by experts for their gait scores. They were also weighed and sexed. Afterwards a statistical relation is sought between the percentages of breast muscle weight (or breast muscle yield) and the gait scores of the animals. It was observed that sex and gait score had a significant effect on the absolute breast muscle weight (p < 0.001 in both cases). On the other hand no evidence was found on the effects of sex and gait score on the breast muscle yield (p = 0.77 and p = 0.42).