Reproductive performance of broiler breeder hens fed n-3 fatty acid-rich fish oil

A study was carried out to investigate the effect of dietary n-3 fatty acid rich fish oil on the reproduction of broiler breeder hens. There were six dietary treatments: (1) basal feed without fat supplements, (2) feed with 3% rendered fat; (3) feed with 2.6% rendered fat +0.4% fish oil; (4) feed with 3% fish oil; (5) feed with 3% fish oil + extra supplements of antioxidant; and (6) feed with 3% fish oil + extra supplements of Vitamin E. The experimental diets were fed to broiler breeder hens from 6 weeks of age until they had produced eggs for hatching tests at 32 weeks of age. The fish-oil diets resulted in negative effects (P < 0.001) on performance with reduced egg weight (about 3 g), increased number of cracked eggs, reduced fertility of eggs and reduced hatchability of fertile eggs. Chicks from breeding hens fed the fish oil diets had reduced weight gain (P < 0.001). Compared with the control diet without fat supplements and the diet with 3% rendered fat, the diets containing 3% fish oil increased the fatty acids C20:5n-3, C22:5n-3 and C22:6n-3 (P < 0.001) and decreased the linoleic acid (C18:2n-6) (P < 0.001) content of egg yolk. There was a tendency towards reduced cholesterol content in egg yolk in the fish oil treatments (P > 0.05). The detrimental effects of feeding n-3 fatty acid rich fish oil could not be prevented by increased dietary supplements of vitamin E or synthetic antioxidants.