title: Hypoxia during embryonic development increases energy metabolism in normoxic juvenile chicks.
abstract: Environmental changes during perinatal development can affect the postnatal life. In this sense, chicken embryos that experience low levels of O2over a specific phase of incubation can have their tissue growth reduced and the ventilatory response to hypoxia blunted, at least until hatching. Additionally, exposure to low level of O2after birth reduces the thermogenesis as well. In the present study, we tested the hypothesis that hypoxia over the third week of incubation affects the thermoregulation of juvenile chicks at an age when thermogenesis is already expected to be well-developed. To this end, we measured body temperature (Tb) and oxygen consumption (V̇02) under acute hypoxia or different ambient temperatures (Ta) of 1 and 10day-old chicks that have been exposed to 21% O2 for entire incubation (Nx) or to 15% O2in the last week of incubation (Hx). We also assessed the thermal preference under normoxia or acute hypoxia of the older chicks from both incubation groups in a thermocline. Hypoxia over incubation reduced growth but did not affect the cold-induced thermogenesis in hatchlings. Regarding the juvenile Hx, present data indicate a catch up growth with higher resting V̇02, a thermal preference for warmer Tas and a possible higher thermal conductance. In conclusion, our results show that hypoxia over the third week of incubation can affect the thermoregulation at least until 10days after hatch in chickens.
authors.affiliation: Department of Animal Morphology and Physiology, College of Agricultural and Veterinarian Sciences, São Paulo State University, Jaboticabal, São Paulo 14884-900, Brazil; National Institute of Science and Technology - Comparative Physiology (INCT-Fisiologia Comparada), Brazil.
authors.forename: Lara do
authors.initials: LD
authors.lastname: Amaral-Silva
authors.affiliation: Department of Animal Morphology and Physiology, College of Agricultural and Veterinarian Sciences, São Paulo State University, Jaboticabal, São Paulo 14884-900, Brazil; National Institute of Science and Technology - Comparative Physiology (INCT-Fisiologia Comparada), Brazil.
authors.forename: Carolina da S
authors.initials: CDS
authors.lastname: Scarpellini
authors.affiliation: Department of Animal Morphology and Physiology, College of Agricultural and Veterinarian Sciences, São Paulo State University, Jaboticabal, São Paulo 14884-900, Brazil.
authors.forename: Paula Andrea
authors.initials: PA
authors.lastname: Toro-Velasquez
authors.affiliation: Department of Animal Science, College of Agricultural and Veterinarian Sciences, São Paulo State University, Jaboticabal, São Paulo 14884-900, Brazil.
authors.forename: Marcia H M R
authors.initials: MHMR
authors.lastname: Fernandes
authors.affiliation: Department of Animal Morphology and Physiology, College of Agricultural and Veterinarian Sciences, São Paulo State University, Jaboticabal, São Paulo 14884-900, Brazil; National Institute of Science and Technology - Comparative Physiology (INCT-Fisiologia Comparada), Brazil.
authors.forename: Luciane H
authors.initials: LH
authors.lastname: Gargaglioni
authors.affiliation: Department of Animal Morphology and Physiology, College of Agricultural and Veterinarian Sciences, São Paulo State University, Jaboticabal, São Paulo 14884-900, Brazil; National Institute of Science and Technology - Comparative Physiology (INCT-Fisiologia Comparada), Brazil. Electronic address: keniacb@yahoo.com.br.
authors.forename: Kênia C
authors.initials: KC
authors.lastname: Bícego
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001833:Body Temperature Regulation / Q000502:physiology*; D002645:Chickens / Q000254:growth & development / Q000378:metabolism*; D047108:Embryonic Development; D004734:Energy Metabolism; D005260:Female; D000860:Hypoxia / Q000378:metabolism; D010101:Oxygen Consumption / Q000502:physiology*; D022722:Thermogenesis / Q000502:physiology
keywords: Body temperature; Hypoxic incubation; Oxygen consumption; Phenotypic plasticity; Thermal preference