Effect of fatty acid saturation in broiler diets on abdominal fat and breast muscle fatty acid composition and susceptibility to lipid oxidation.

A total of 600 1-d-old Hybro N broiler chicks were randomly distributed into 24 litter pens and fed from 21 to 52 d of age isocaloric and isonitrogenous diets containing 8% of three different fat sources (tallow, lard or sunflower oil). Dietary treatment produced a significant effect (P < 0.05) in fatty acid composition of the intramuscular neutral lipids among all dietary treatments and for all lipid classes. A similar range of variation was obtained for abdominal fat fatty acid composition. In the intramuscular polar lipid fraction, dietary fat led to a narrow range in the variation of poly- and monounsaturated fatty acid composition, while the concentration of saturated fatty acids was maintained constant in all groups. A wide range in the melting point temperature of abdominal fat was observed (mean values of dietary treatments from 8.49 to 30.91 C), which indicates a major effect of dietary fatty acids on fat consistency. The variation of breast meat oxidation was small (mean values from 7.68 to 9.76 nmol malonaldehyde/mg protein). A dietary fat source rich in linoleic acid produces a marked effect on fat consistency, but only a moderately higher susceptibility to lipid oxidation of meat compared to tallow or lard.