A Study on the Effect of Diets Rich in Omega-3 Fatty Acids on Performance, Blood Parameters and Profile of Egg Yolk Fatty Acids in Laying Hens Under Physiological Stress

Omega-3 fatty acids can be conducive toreducing the harmful effects of physiological stress through reducing the stimulatory activity of glutamatergic neurons.

The aim of this study was to investigate the effects of omega-3 fatty acids on performance, blood parameters, and the profile of fatty acids in the egg yolks of laying hen under stress.

This study was performed using 96 LSL-Lite laying hens in a 2 × 3 factorial experiment with 2 factors, namely stress (no dexamethasone and 1.5 mg/kg of diet dexamethasone) and omega-3 fatty acids (the levels of 0, 0.24 and 0.48 % of diet), in a completely randomized design for 70 days from 35 to 44 weeks of age.

Physiological stress reduced the feed intake, the percentage of egg production, and egg mass in laying hens (P<0.05). Omega-3 fatty acid supplements had no effects on these traits. The groups receiving 0.48 % of omega-3 fatty acids had the lowest heterophil:lymphocytes (P<0.05), and there was no difference between stressed and non-stressed groups. The ratio of omega-6 to omega-3 fatty acids was higher in birds previously affected by stress (P<0.05). Feeding with omega-3 fatty acids in birds increased omega-3 fatty acids in egg yolk and reduced the ratio of omega-6 fatty acids to omega-3 in laying hens (P<0.05).

Based on the results of this experiment, physiological stress had a negative effect on performance traits, and the use of omega-3 fatty acids in laying hens under stress had no effect on performance traits. Physiological stress altered the profile of fatty acids and increased the proportion of omega-6 to omega-3 fatty acids in egg yolk. The use of omega-3 fatty acids reduced the negative effects of stress and improved the profile of fatty acids in egg yolk.