title: Exposure of embryos to cyclically cold incubation temperatures durably affects energy metabolism and antioxidant pathways in broiler chickens.
abstract: Cyclically cold incubation temperatures have been suggested as a means to improve resistance of broiler chickens to ascites; however, the underlying mechanisms are not known. Nine hundred eggs obtained from 48 wk Ross broiler breeders were randomly assigned to 2 incubation treatments: control I eggs were incubated at 37.6°C throughout, whereas for cold I eggs the incubation temperature was reduced by 1°C for 6 h daily from 10 to 18 d of incubation. Thereafter, chickens were reared at standard temperatures or under cold exposure that was associated or not with a postnatal cold acclimation at d 5 posthatch. At hatch, hepatic catalase activity and malondialdehyde content were measured. Serum thyroid hormone and triglyceride concentrations, and muscle expression of several genes involved in the regulation of energy metabolism and oxidative stress were also measured at hatch and 5 and 25 d posthatch. Cold incubation induced modifications in antioxidant pathways with higher catalase activity, but lower expression of avian uncoupling protein 3 at hatch. However, long-term enhancement in the expression of avian uncoupling protein 3 was observed, probably caused by an increase in the expression of the transcription factor peroxisome proliferator activated receptor-γ coactivator-1α. These effects were not systematically associated with an increase in serum triiodothyronine concentrations that were observed only in chickens exposed to both cold incubation and later acclimation at 5 d with cold rearing. Our results suggest that these conditions of cyclically cold incubation resulted in the long-term in changes in antioxidant pathways and energy metabolism, which could enhance the health of chickens reared under cold conditions.
authors.affiliation: INRA, UR83 Recherches Avicoles, F-37380 Nouzilly, France.
authors.forename: T
authors.initials: T
authors.lastname: Loyau
authors.affiliation: INRA, UR83 Recherches Avicoles, F-37380 Nouzilly, France Anne.Collin@tours.inra.fr.
authors.forename: A
authors.initials: A
authors.lastname: Collin
authors.affiliation: Adnan Menderes University, Medicine Faculty, 09100 Aydın, Turkey.
authors.forename: C
authors.initials: C
authors.lastname: Yenisey
authors.affiliation: INRA, UR83 Recherches Avicoles, F-37380 Nouzilly, France.
authors.forename: S
authors.initials: S
authors.lastname: Crochet
authors.affiliation: Virginia Polytechnic Institute and State University, Department of Animal and Poultry Sciences, Blacksburg 24061-0306.
authors.forename: P B
authors.initials: PB
authors.lastname: Siegel
authors.affiliation: Adnan Menderes University, Faculty of Agriculture, Department of Animal Science, 09100 Aydın, Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Akşit
authors.affiliation: Ege University, Faculty of Agriculture, Department of Animal Science, 35100 Izmir, Turkey.
authors.forename: S
authors.initials: S
authors.lastname: Yalçin
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002642:Chick Embryo / Q000254:growth & development; D002645:Chickens / Q000502:physiology*; D003080:Cold Temperature; D004734:Energy Metabolism; D005786:Gene Expression Regulation; D008099:Liver / Q000502:physiology*; D018384:Oxidative Stress; D010369:Pectoralis Muscles / Q000502:physiology*; D011897:Random Allocation
chemical_list: D000975:Antioxidants
keywords: acclimation; chicken; cold incubation; energy metabolism; oxidative stress