Maternal diet with diverse omega-6/omega-3 ratio affects the brain docosahexaenoic acid content of growing chickens

Abstract

Eggs with diverse omega-6/omega-3 ratio produced by feeding breeder hens a wheat-soybean meal-basal diet containing 5% (wt/wt) sunflower oil (H(omega)6), 5% fish oil (H(omega)3) or 2.5% sunflower oil plus 2.5% fish oil (M(omega)3omega6) were incubated. The hatched chicks were fed a docosahexaenoic acid (DHA)-deficient diet up to 6 weeks of age. The fatty acid composition of chick brain was determined on 0, 2, 4 and 6 weeks and brain weight was taken on day 0 and day 42. The omega-6/omega-3 ratios were 37.12, 4.21 and 0.98 for the maternal diet; 28.36, 2.83 and 0.89 for the egg yolk; 1.94, 0.48 and 0.18 for hatched chick brain (p < 0.05). At 2 weeks of age, the omega-6/omega-3 ratios were 1.88, 0.81 and 0.60 for chicks hatched from hens fed H(omega)6, M(omega)3omega6 and H(omega)3 diets, respectively. The brain DHA contents at 0 and 2 weeks of age were Homega3 > M(omega)3omega6 < H(omega)6 (p < 0.05) and at 4 and 6 weeks of age H(omega)3 = M(omega)3omega6 > H(omega)6. Dietary C18:3omega3 in the starter and finisher diet did not increase brain DHA (p > 0.05). The significant increase in the content of C22:5omega3 at 6 weeks of age in group 1 birds with a concomitant reduction in DHA suggests a weak delta-4 desaturation but an effective delta-6 and delta-5 desaturation similar to human infants. Considering the role of DHA in early brain development and growth, the maternal supply of DHA during growth might be of importance when fed a DHA-deficient neonatal diet.