title: Daily variations in the thermoregulatory behaviors of naked neck broilers in an equatorial semi-arid environment.
abstract: The aim of this study was to evaluate the daily variations in the thermoregulatory behavior of 4- to 6-week-old naked neck broilers (Label Rouge) in an equatorial semi-arid environment. A total of 220 birds were monitored for 5 days starting at 0600 hours and ending at 1800 hours. The period of observation was divided into classes of hours (C H). The observed behaviors were as follows: feed and water intake, wing-spreading, sitting or lying, and beak-opening. A total of 14,300 behavioral data values were registered. In C H 2 (0900 hours to 1100 hours) and 3 (1200 hours to 1500 hours), the greatest average body surface temperature was recorded (34.67 ± 0.25 °C and 35.12 ± 0.22 °C, respectively). The C H had an effect on the exhibition of all behaviors with the exception of the water intake behavior. Feed intake was more frequent in C H 1 (0600 hours to 0800 hours) and 4 (1600 hours to 1800 hours). In C H 2 and 3, the highest frequency of sitting or lying behavior was observed. Beak-opening and wing-spreading behaviors occurred more frequently in C H 3 where the body surface temperature (35.12 ± 0.22 °C), radiant heat load (519.38 ± 2.22 W m(-2)), and enthalpy (82.74 ± 0.36 kJ kg(-1) of dry air) reached maximum recorded averages. Thus, it can be concluded that naked neck broilers adjust their behavior in response to daily variations in the thermal environment. Wing-spreading and beak-opening behaviors are important adaptive responses to the thermal challenges posed by the equatorial semi-arid environment.
authors.affiliation: Department of Animal Science, Rural Federal University of Semi-Arid, Mossoró Campus, 59625-900, Mossoró, RN, Brazil, jp.fernandes@yahoo.com.br.
authors.forename: João Paulo Araújo Fernandes
authors.initials: JP
authors.lastname: de Queiroz
authors.forename: João Batista Freire
authors.initials: JB
authors.lastname: de Souza
authors.forename: Hiagos Felipe Ferreira
authors.initials: HF
authors.lastname: de Lima
authors.forename: Monik Kelly
authors.initials: MK
authors.lastname: de Oliveira Costa
authors.forename: Leonardo Lelis
authors.initials: LL
authors.lastname: de Macedo Costa
authors.forename: Alex Martins Varela
authors.initials: AM
authors.lastname: de Arruda
mesh_terms: D000818:Animals; D001502:Beak / Q000502:physiology; D001522:Behavior, Animal; D001833:Body Temperature Regulation; D001938:Brazil; D002645:Chickens / Q000502:physiology*; D002980:Climate; D004435:Eating; D005260:Female; D008297:Male; D014921:Wings, Animal / Q000502:physiology