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

Abstract

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.

Transgenerational epigenetic inheritance in birds

“…In a more applied, on-farm study in laying hens, de Haas et al [ 48 ] showed that offspring from parent stock with high basal CORT were more anxious and more likely to develop severe feather pecking (FP) behaviour in the first weeks of life than offspring from parents with lower basal CORT levels. Additionally, changes in fatty acid concentrations in the mother diet of laying hens modified egg mass, yolk-lipid composition, yolk-hormone concentration, weight at hatch and fear of novelty in the offspring [ 49 ]. In Japanese quail, another selected bird species, simulating maternal stress by injection of eggs with CORT resulted in an attenuated stress response in their offspring, with maternal pre-natal stress being more important on the offspring’s physiological response than post-natal stress [ 50 ].…”

“…Many behaviours in the chicken are affected by early environmental factors and maternal hormones, such as learning, food choice, stress response [ 44 ] and neophobia [ 49 ]. Likely also maladaptive redirected FP could be influenced by early environment.…”

Prenatal and Early Postnatal Behavioural Programming in Laying Hens, With Possible Implications for the Development of Injurious Pecking

“…Maternal nutritional stress has also been manipulated in studies on laying hens. A higher ratio of omega-3 to omega-6 polyunsaturated fatty acids in the maternal diet was associated with increased faecal corticosterone metabolites (FCMs) in the hens and elevated fear of a novel object in their chicks (52). Thwarting hens' access to feed for 6 h daily at unpredictable times was also associated with elevated FCM in the hens and more fearful, less competitive adult female offspring (53).…”

Human behaviour at the origin of maternal effects on offspring behaviour in laying hens (Gallus gallus domesticus)

“…So far, housing conditions [13], unpredictable access to food [14,15], maternal social status [16], thermal environment [12] or maternal diet [17] are all factors identified as potential sources of maternal effects mediated by yolk hormone variations in domestic chickens. These environmental factors caused modifications in growth, feeding behaviour, or emotional reactivity of the progeny [18] [15] [12] [17]. As these behaviours are implicated in chicks' capacity to adapt to their environement, deepening our understanding of maternal effects is of importance to contribute to a better management of layer breeders.…”