title: Age and gender influence the cardiorespiratory function and metabolic rate of broiler chicks during normocapnia and hypercapnia.
abstract: Pulmonary ventilation (V˙(E)), body temperature (Tb), mean arterial pressure (MAP), heart rate (f(H)) and metabolic rate (V˙(O2)) were measured in 10 (d10)- and 21 (d21)-day-old male and female chicks exposed to 7% CO2. Under normocapnia, V˙(E) was higher in d10 chicks than in d21 due to a higher tidal volume; in females a higher respiratory frequency (f(R)) was also observed. The d10 birds presented higher f(H) and V˙(O2). The d21 females showed the highest CO2 ventilatory response due to increased f(R). MAP did not change during hypercapnia while a hypercapnic bradycardia occurred, except in d21 females. Hypercapnia induced a drop in Tb in all groups and an increase in V˙(O2) in d21 males. Overall, no gender effect is observed in cardiorespiratory and metabolic variables in d10 and d21 chicks under normocapnia, the differences in V˙(E) and f(H) between ages may be related to distinct metabolic demands of these phases. The d21 female chicks seem to be more sensitive to hypercapnia.
authors.affiliation: Department of Animal Morphology and Physiology, São Paulo State University - (UNESP FCAV), Jaboticabal, SP, Brazil; National Institute of Science and Technology in Comparative Physiology (INCT-FisiologiaComparada), Brazil.
authors.forename: Lívia P
authors.initials: LP
authors.lastname: Espinha
authors.affiliation: Department of Animal Morphology and Physiology, São Paulo State University - (UNESP FCAV), Jaboticabal, SP, Brazil.
authors.forename: Fernando A
authors.initials: FA
authors.lastname: Souza
authors.affiliation: Department of Animal Morphology and Physiology, São Paulo State University - (UNESP FCAV), Jaboticabal, SP, Brazil.
authors.forename: Aretuza C
authors.initials: AC
authors.lastname: Capalbo
authors.affiliation: Department of Animal Morphology and Physiology, São Paulo State University - (UNESP FCAV), Jaboticabal, SP, Brazil; National Institute of Science and Technology in Comparative Physiology (INCT-FisiologiaComparada), Brazil.
authors.forename: Kênia C
authors.initials: KC
authors.lastname: Bícego
authors.affiliation: Department of Animal Morphology and Physiology, São Paulo State University - (UNESP FCAV), Jaboticabal, SP, Brazil.
authors.forename: Marcos
authors.initials: M
authors.lastname: Macari
authors.affiliation: Department of Animal Morphology and Physiology, São Paulo State University - (UNESP FCAV), Jaboticabal, SP, Brazil; National Institute of Science and Technology in Comparative Physiology (INCT-FisiologiaComparada), Brazil. Electronic address: lucihel@fcav.unesp.br.
authors.forename: Luciane H
authors.initials: LH
authors.lastname: Gargaglioni
mesh_terms: D000818:Animals; D062186:Arterial Pressure / Q000502:physiology; D001481:Basal Metabolism / Q000502:physiology; D001774:Blood Chemical Analysis; D001831:Body Temperature / Q000502:physiology; D002245:Carbon Dioxide / Q000378:metabolism; D002645:Chickens / Q000254:growth & development* / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006935:Hypercapnia / Q000503:physiopathology*; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D012123:Pulmonary Ventilation / Q000502:physiology; D012727:Sex Characteristics; D013990:Tidal Volume
chemical_list: D002245:Carbon Dioxide
keywords: Bird; CO(2) chemosensitivity; Metabolic rate; Thermoregulation; Ventilation