Lipids in maternal diet influence yolk hormone levels and post‐hatch neophobia in the domestic chick

We assessed whether the ratio of dietary n‐6/n‐3 polyunsaturated fatty acids (PUFA) during egg formation engenders transgenerational maternal effects in domestic chicks. We analyzed yolk lipid and hormone concentrations, and HPA‐axis activity in hens fed a control diet (high n‐6/n‐3 ratio) or a diet enriched in n‐3 PUFAs (low n‐6/n‐3 ratio) for 6 consecutive weeks. Their chicks were tested for neophobia during the first week of life. We found higher corticosterone metabolites in droppings of hens fed the diet enriched in n‐3 and significantly higher concentrations of yolk progesterone, androstenedione, and estradiol in their eggs compared to controls. Chicks of hens fed the n‐3 enriched diet showed a lower body mass at hatch than controls and expressed higher neophobia when exposed to a novel object. These results add support to the hypothesis that the nutritional state of female birds produces variation in yolk hormone levels and engender maternal effects.