Effects of feeding extruded flaxseed on layer performance, total tract nutrient digestibility, and fatty acid concentrations of egg yolk, plasma and liver.

A study was conducted to determine the effects of graded levels of extruded flaxseed (EF) on laying hen performance, apparent total tract nutrient retention (ATTNR) and fatty acid concentrations of egg yolk, blood plasma and liver. Seventy-two White Leghorn layers (58 weeks old; three per cage) were randomly assigned to one of four dietary treatments: 0 (control), 3, 6 and 9% of EF-supplemented diets for 8 weeks. Results showed that feed intake, egg production, feed conversion ratio and egg weight were not affected by treatments. The ATTNR of dry matter (p = .001) and gross energy (p = .014) was lower for layers fed 9% EF than those fed the control diet, while ATTNR of organic matter (p = .001) and nitrogen-corrected apparent metabolizable energy (p = .003) were lower for birds fed 6% and 9% EF compared with those fed the control diet. Relative to the control diet, feeding EF increased (p < .001) egg yolk, plasma and liver n-3 polyunsaturated fatty acid (PUFA) concentrations. Birds fed 6% EF produced eggs > 300 mg of n-3 PUFA after two weeks of feeding, while the highest of n-3 PUFA concentrations were achieved for birds fed 9% EF. It was concluded that feeding EF up to 9% of the diet had no adverse effects on layer performance and increased n-3 PUFA concentrations in blood plasma, liver and egg yolk. However, moderate to high levels of EF (i.e., 6% and 9% of the diet) reduced nutrient ATTNR and nitrogen-corrected apparent metabolizable energy. Omega-3-enriched eggs can be achieved by feeding layers EF at 6% of the diet.