Relative contribution of breed, slaughter weight, sex and diet to the fatty acid composition of differentiated pork

The objective of this study was to investigate the relative contribution of breed composition, slaughter weight, sex, diet, and their interactions to the fatty acid composition of intramuscular and subcutaneous fat of pigs. Sires from Duroc, Lacombe, and Iberian breeds were crossed to Large White × Landrace dams and offspring (barrows and gilts) were randomly allocated into three feeding groups (Control, Canola or Flax) 3 wk before slaughter, aiming at slaughter weights of either 115 or 135 kg. In intramuscular fat, dietary treatment (88.7%) was responsible for most of the explained variability observed in 18:3 n-3 (0.76), followed by breed and the breed × diet interaction. In subcutaneous fat, the same factors contributed for the explained variance in 18:3 n-3 (0.84) in a similar order. Furthermore, diet contributed more than 94% to the explained variability observed in n-6/n-3 (0.90). On the other hand, both for the intramuscular and subcutaneous fat, breed was the most influential factor (68.9%/68.2%, respectively) for the explained variance in 18:2 n-6 (0.38/0.59, respectively). Both sex and slaughter weight also had significant effects (P < 0.05) on some individual fatty acids and indices. Understanding the contribution of each factor and their interactions will help the pork industry in the production of consistent differentiated products.