&lt;b&gt;Thermoregulatory responses of female buffaloes reared under direct sunlight and shaded areas in the dry season on Marajó Island, Brazil

Waleria Cristina Lopes Joset,Lucieta Guerreiro Martorano,Jamile Andréa Rodrigues Da Silva,Letícia Athaíde Godinho,Antônio Vinicius Corrêa Barbosa,José De Brito Lourenço Júnior

doi:10.4025/actascianimsci.v40i1.37641

Abstract

This research aimed to assess the effects of dry season climate variables on Marajo Island, Brazil, on the thermoregulatory responses of twenty female buffaloes, assigned to shaded (SD), and unshaded groups (US). Data on air temperature (AT), relative air humidity, wind velocity (WV), respiratory rate (RR), rectal temperature (RT), and body surface temperature (BST) were recorded at 6 a.m., 10 a.m., 2 p.m., 6 p.m., and 10 p.m. The temperature and humidity index (THI), practical buffalo comfort climatic conditions index (BCCCIp), and practical buffalo environmental comfort index (BECIp) were calculated. At 10 a.m. and 2 p.m., WV was the highest. The RR of animals in both treatments differed only at 10 a.m. and 2 p.m. A difference in RT between treatments was seen at 10 a.m., 2 a.m., and 6 p.m. Significant changes were seen in the BST of animals in both groups at 10 a.m., 2 p.m., and 10 p.m. BECIp was different between the groups at 10 a.m. and 2 p.m., with higher values for the US group. Buffaloes are prone to thermal stress, particularly between 10 a.m. and 2 p.m., when the highest values of AT, THI, and BCCCIp was observed.

Highlights

The buffalo herd was introduced in the Brazilian territory of Marajó Island, Pará by the end of the 19th century (Damé, Riet-Correa, & Schild, 2013)
temperature and humidity index (THI) values up to indicate non-stressful environmental conditions; between and 78, conditions are critical; between 79 and 83 is defined as danger; and above 83, conditions are considered as being in an emergency situation (Du Preez, 2000)
A difference (p < 0.05) was found between the treatments at 10 a.m., when only the unshaded groups (US) group was in an emergency condition, with a higher THI value (84.00 ± 1.01)

Summary

Introduction

The buffalo herd was introduced in the Brazilian territory of Marajó Island, Pará by the end of the 19th century (Damé, Riet-Correa, & Schild, 2013) Those animals adapted very well to the environmental conditions in the Amazon due to the similarity between local environmental conditions with those of their countries of origin, characterized by the predominantly tropical climate, and after introduction continued developing and adapting to the conditions of the island due to the great capacity of adaptation of these buffaloes to different types of environments. That occurs because they have specific morphological characteristics, such as a high concentration of melanin in the skin and hair, a small number of sweat glands that have reduced efficiency, and low hair density, which makes them sensitive to solar radiation (Gudev et al, 2007)

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Results