Fat deposition in a broiler sire strain

The development in poultry meat production and consumption causes changes in the type of broiler demanded. At the onset of specialized broiler production, most improvements were made by intensive selection for weight gain, whereas little attention was given to carcass composition or quality, other than the shape of the whole carcass.

The increasing quality awareness of consumers and their increasing demand for chicken parts and further processed products require properties of the broiler other than fast weight gain only. For further processing, the anatomical composition of chickens determines for a large part the yield for the slaughter plant. The proportion of offal is of more importance when parts are produced than when whole carcasses are the end product. Fat depots are anatomical parts that are considered as offal nowadays, the more so as consumers are advised to diminish their fat consumption.

Processing yields worsen when fat depots are removed from the carcass. When not removed, they can affect the healthy and low-in-fat-content image of poultry meat. The low fat content is a main reason why poultry meat is preferred above red meat. The main fat depot in broilers is the abdominal fat. It extends from the cloaca over the intestines and around the gizzard. The abdominal fat forms about 2.5% of the total live weight of a broiler. This implies that in the Netherlands more than 10000 tons of abdominal fat are produced per year.

Against this background, in 1980 a research program was started at the Spelderholt Centre aimed at reducing fatness in broilers. The purpose of the program was to examine the possibilities and the consequences of selection against fatness. The results of the research program are set forth in this thesis