Models to predict both sensible and latent heat tr

Authors: Vinícius Carvalho Fonseca Edilson Paes Saraiva Alex Sandro Campos Maia Carolina Cardoso Nagib Nascimento Josinaldo Araújo da Silva Walter Esfraim Pereira Edgard Cavalcanti Pimenta Filho Maria Elivânia Vieira Almeida

Publish Date: 2016/10/10

Volume: 61, Issue: 5, Pages: 777-784

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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 ± 12 years old and average body weight of 3276 ± 372 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 humidityWe gratefully acknowledge the support of the Animal Science Department and Animal Biometeorology Laboratory of the Universidade Estadual de São Paulo Brazil This study was supported by Research Foundation of São Paulo State FAPESP Process number 2011/173886 We thank all members of the Behaviour and Biometeorology Group of the Universidade Federal da Paraíba BIOET and the members of the Animal Biometeorology Innovation Group of the Universidade Estadual de São Paulo INOBIO

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