Dietary enrichment of n-3 PUFA for laying hens: effect of different sources on production, composition and quality of eggs

Seventy-two Warren strain laying hens were fed 4 isonitrogenous diets ad libitum for 61 days in order to investigate the effects of different sources of n-3 polyunsaturated fatty acids (PUFA) on hen performance, egg production, fatty acid (FA) composition and egg quality. Extruded linseed (EL), ground linseed (GL) and a commercial fish oil source (NF) were added to the control diet (C) at 10.0, 10.0 and 3.4%, respectively. The eggs were collected daily and subjected to measurement and analysis ten times throughout the experimental period. Compared to the C diet, the NF diet significantly improved egg production efficiency (P<0.01) and overall egg weight/hen ratio (P<0.05), whereas the GL and NF diets led to a reduction in hen weight gain (P<0.01). Equilibrium in the yolk FA profile was reached after 14 days of dietary n-3 PUFA source inclusion. All experimental diets significantly affected yolk FA composition and reduced the n-6/n-3 ratio (11.4, 2.0, 2.3, and 2.0 at equilibrium for C, EL, GL, and NF, respectively; P<0.05). Yolk redness (a* values: -1.13 vs -2.25 and -2.96) and yellowness (b* values: 50.7 vs 48.5 and 48.2) were significantly reduced by both linseedsupplemented diets (C vs EL and GL, respectively; P<0.05). Moreover, the form of linseed in the diet (extruded vs ground) significantly affected yolk n-3 PUFA content (7.1 vs 6.4% total FAME for EL and GL, respectively; P<0.05), and the extruded form significantly enhanced the rate of inclusion, thereby illustrating the importance of feed source processing in egg quality traits.