Fatty Acid Metabolism in Broiler Chickens Fed Diets Either Rich in Linoleic or Alpha-Linolenic Acid

The study with broiler chickens aimed to test the hypothesis that the feeding of the n-3 Polyunsaturated Fatty Acid (PUFA), Alpha-Linolenic Acid (ALA) results in more whole-body fatty acid oxidation than the feeding of the n-6 PUFA, Linoleic Acid (LA). It was reasoned that the increased fatty acid oxidation, if any, would be associated with enhanced whole-body energy expenditure. Broiler chickens were fed diets containing either a soybean-oil blend as source of LA or a linseed-oil blend as source of ALA. Seven-day-old, male broiler chickens were used; they were kept individually in cages from 1 to 4 weeks of age. Energy expenditure was calculated on the basis of the whole-body energy balance. For individual fatty acids, the apparent digestibility and deposition in the body was determined. The ALA diet raised the ratio of deposition in the body to intake of digestible LA and diminished that of ALA. This points at preferential oxidation of ALA, at the expense of LA, in the birds fed the ALA diet. Feeding the high-ALA instead of the high-LA diet did not influence energy expenditure when expressed as percentage of energy intake. This study supports the idea that dietary ALA versus LA is preferentially oxidized, but contrary to the hypothesis it was associated with unchanged energy expenditure.