The Influence of Genetic Increases in Body Weight on the Abdominal Fat Pad of Turkeys

A strain (F) in which 16-week body weight had been increased 2.22 and 2.00 kg in males and females, respectively, after 14 generations of selection for increased 16-week body weight was compared with its corresponding randombred control (RBC2) for weight of the abdominal fat pad at 20 weeks of age. At 20 weeks of age, body weight of the F strain was 2.58 and 2.23 kg greater for males and females, respectively, than that of the RBC2 strain. The comparison was made on offspring in three weekly hatches. Because different buildings were used for the hatches, the effects of hatches and buildings were confounded. The increase in body weight of the F strain was associated with an increase in the size of the abdominal fat pad (both actual weight and weight expressed as percent of live body weight). The abdominal fat pad was larger in females than in males. Hatch (building) effects and the interaction of strain and hatch were significant sources of variation in abdominal fat pad weight. The linear regression coefficients of abdominal fat pad weight on body weight differed between sexes and strains. The coefficients were larger for the F strain than the RBC2 strain and were higher for females than for males.