Effect of age, sex, genotype and environment on fat deposition in broiler chickens—A review

SummaryThe possibilities of preventing excessive fat deposition in broiler chickens are reviewed. Both the total amount of fat deposited and the ratio between abdominal fat and total fat can be changed by nutritional and genetic means. The effects of environmental factors like housing design, temperature and lighting regimes on fat deposition are too small to be useful for preventing excessive fat deposition.Most important among nutritional factors is the ratio between energy and protein in the diet. Several other dietary factors and their interactions also have a marked influence on fat deposition. Information on the effects of interactions between dietary components among each other and between nutrition and sex, age and genotype of the broiler is however far from complete.Selection can solve the problem of excessive fat deposition in the longer term in an effective way, although more research is needed on the effects of selection against fatness on growth rate, feed conversion, slaughter yields and the quality of the broiler from a consumer's point of view.