Studies on Abdominal Fat with Four Commercial Strains of Male Broiler Chicken

Cockerels from four commercial broiler strain crosses were used to study strain differences in abdominal fat deposition. Ninety birds of each strain were floor reared to four weeks of age. At this age, 40 birds of each strain were transferred to individual cages, while the remainder were used for carcass studies. Individual bird feed intake was measured to eight weeks of age, at which time all birds were killed for carcass and abdominal fat measurements. Strain differences were noted in abdominal fat, although the variation between individuals was large (coefficient of variation 26%) thus leaving the interpretation of such differences and their correlation with performance data, open to question. When data were grouped from the extremes in ranking for abdominal fat, and expressed as a sub-sample mean effect, a significant difference in 8 week body weight was observed. Comparable groupings based on body weight and feed conversion had no significant influence on abdominal fat. These results raise the question as to whether or not meaningful extremes within a population could provide the basis for a selection program aimed at reducing abominal fat pad size.