title: Models to predict both sensible and latent heat transfer in the respiratory tract of Morada Nova sheep under semiarid tropical environment.
abstract: The aim of this study was to build a prediction model both sensible and latent heat transfer by respiratory tract for Morada Nova sheep under field conditions in a semiarid tropical environment, using easily measured physiological and environmental parameters. Twelve dry Morada Nova ewes with an average of 3 ± 1.2 years old and average body weight of 32.76 ± 3.72 kg were used in a Latin square design 12 × 12 (12 days of records and 12 schedules). Tidal volume, respiratory rate, expired air temperature, and partial vapor pressure of the expired air were obtained from the respiratory facial mask and using a physiological measurement system. Ewes were evaluated from 0700 to 1900 h in each day under shade. A simple nonlinear model to estimate tidal volume as a function of respiratory rate was developed. Equation to estimate the expired air temperature was built, and the ambient air temperature was the best predictor together with relative humidity and ambient vapor pressure. In naturalized Morada Nova sheep, respiratory convection seems to be a mechanism of heat transfer of minor importance even under mild air temperature. Evaporation from the respiratory system increased together with ambient air temperature. At ambient air temperature, up to 35 °C respiratory evaporation accounted 90 % of the total heat lost by respiratory system, on average. Models presented here allow to estimate the heat flow from the respiratory tract for Morada Nova sheep bred in tropical region, using easily measured physiological and environmental traits as respiratory rate, ambient air temperature, and relative humidity.
authors.affiliation: Universidade Federal da Paraiba, Paraiba, Areia, Brazil. vinicius_fonseca86@hotmail.com.
authors.forename: Vinícius Carvalho
authors.initials: VC
authors.lastname: Fonseca
authors.affiliation: Universidade Federal da Paraiba, Paraiba, Areia, Brazil.
authors.forename: Edilson Paes
authors.initials: EP
authors.lastname: Saraiva
authors.affiliation: Universidade Estadual Paulista, São Paulo, Jaboticabal, Brazil.
authors.forename: Alex Sandro Campos
authors.initials: ASC
authors.lastname: Maia
authors.affiliation: Universidade Estadual Paulista, São Paulo, Jaboticabal, Brazil.
authors.forename: Carolina Cardoso Nagib
authors.initials: CCN
authors.lastname: Nascimento
authors.affiliation: Universidade Federal da Paraiba, Paraiba, Areia, Brazil.
authors.forename: Josinaldo Araújo
authors.initials: JA
authors.lastname: da Silva
authors.affiliation: Universidade Federal da Paraiba, Paraiba, Areia, Brazil.
authors.forename: Walter Esfraim
authors.initials: WE
authors.lastname: Pereira
authors.affiliation: Universidade Federal da Paraiba, Paraiba, Areia, Brazil.
authors.forename: Edgard Cavalcanti Pimenta
authors.initials: ECP
authors.lastname: Filho
authors.affiliation: Universidade Federal da Paraiba, Paraiba, Areia, Brazil.
authors.forename: Maria Elivânia Vieira
authors.initials: MEV
authors.lastname: Almeida
mesh_terms: D000818:Animals; D001833:Body Temperature Regulation; D005260:Female; D006813:Humidity; D008954:Models, Biological; D012143:Respiratory Physiological Phenomena; D012137:Respiratory System; D012756:Sheep / Q000502:physiology*; D013696:Temperature; D014329:Tropical Climate
keywords: Genetic adaptation; Naturalized breed; Prediction model; Tidal volume