Effects of dietary fatty acid pattern on melting point and composition of adipose tissues and intramuscular fat of broiler carcasses.

Soybean oil (SO), rapeseed oil (RO), or two commercial fat products (FP1, FP2) were incorporated at 3.5% levels into four different corn-soybean meal mash broiler diets. Each of the four diets was fed to five replicates (pens) of broiler chickens for 42 d. After slaughtering the birds, samples of the abdominal fat, subcutaneous fat, and fat extracted from the thigh and the breast portion were collected from 16 birds per treatment. The fat samples were analyzed for their fatty acid composition using gas chromatography and the melting point of the abdominal fat was recorded. The results showed that the abdominal and subcutaneous fat had very similar fatty acid patterns and differed significantly from the composition of the fat extracted from breast and thigh. The different dietary treatments caused significant changes in the fatty acid patterns for all analyzed tissues, although the differences were more pronounced for the adipose tissues. Overall, the adipose tissues contained more polyunsaturated and less saturated fatty acids than the fat from the breast and thigh portions. The melting point of the abdominal fat was significantly altered by the use of different dietary fats: RO gave a lower melting point than SO and FP1; the highest values were recorded for FP2. The data presented here indicate that the selection of certain dietary fat sources has a major impact on the composition and the melting point of broiler adipose tissues. The effect on the fatty acid composition of meat portions, however, is limited.