title: Moderate heat challenge increased yolk steroid hormones and shaped offspring growth and behavior in chickens.
abstract: BACKGROUND
  Environmental challenges might affect the maternal organism and indirectly affect the later ontogeny of the progeny. We investigated the cross-generation impact of a moderate heat challenge in chickens. We hypothesized that a warm temperature--within the thermotolerance range--would affect the hormonal environment provided to embryos by mothers, and in turn, affect the morphology and behavioral phenotype of offspring.
  
  
  RESULTS
  Laying hens were raised under a standard thermal condition at 21°C (controls) or 30°C (experimental) for 5 consecutive weeks. A significant increase was observed in the internal temperature of hens exposed to the warm treatment; however plasma corticosterone levels remained unaffected. The laying rate was not affected, but experimental hens laid lighter eggs than the controls during the treatment. As expected, the maternal thermal environment affected yolk hormone contents. Eggs laid by the experimental hens showed significantly higher concentrations of yolk progesterone, testosterone, and estradiol. All chicks were raised under standard thermal conditions. The quality of hatchlings, growth, feeding behavior and emotional reactivity of chicks were analyzed. Offspring of experimental hens (C30 chicks) were lighter but obtained better morphological quality scores at hatching than the controls (C21 chicks). C30 chicks expressed lesser distress calls when exposed to a novel food. Unlike C21 chicks, C30 chicks expressed no preference for energetic food.
  
  
  CONCLUSIONS
  Our findings suggest that moderate heat challenge triggers maternal effects and modulate the developmental trajectory of offspring in a way that may be adaptive. This suggests that the impact of heat challenges on captive or wild populations might have a cross-generation effect.
authors: Institut National de la Recherche Agronomique-INRA, UMR85, Physiologie de la Reproduction et des Comportements, Nouzilly, France. aline.bertin@tours.inra.fr
authors: Aline
authors: A
authors: Bertin
authors: Marine
authors: M
authors: Chanson
authors: Joël
authors: J
authors: Delaveau
authors: Frédéric
authors: F
authors: Mercerand
authors: Erich
authors: E
authors: Möstl
authors: Ludovic
authors: L
authors: Calandreau
authors: Cécile
authors: C
authors: Arnould
authors: Christine
authors: C
authors: Leterrier
authors: Anne
authors: A
authors: Collin
mesh_terms: D000818:Animals; D002642:Chick Embryo; D002645:Chickens / Q000378:metabolism / Q000502:physiology*; D015988:Cohort Effect; D003345:Corticosterone / Q000378:metabolism; D004530:Egg Yolk / Q000378:metabolism*; D004644:Emotions / Q000502:physiology; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D012739:Gonadal Steroid Hormones / Q000378:metabolism*; D006358:Hot Temperature; D010641:Phenotype
chemical_list: D012739:Gonadal Steroid Hormones; D003345:Corticosterone