Are locally adapted goats able to recover homeothermy, acid-base and electrolyte equilibrium in a semi-arid region?

Débora Andréa Evangelista Façanha; Josiel Ferreira; Robson Mateus Freitas Silveira; Talyta Lins Nunes; Maria Gláucia Carlos de Oliveira; José Ernandes Rufino de Sousa; Valéria Veras de Paula

doi:10.1016/j.jtherbio.2020.102593

Are locally adapted goats able to recover homeothermy, acid-base and electrolyte equilibrium in a semi-arid region?

J Therm Biol. 2020 May:90:102593. doi: 10.1016/j.jtherbio.2020.102593. Epub 2020 Apr 14.

Authors

Débora Andréa Evangelista Façanha¹, Josiel Ferreira², Robson Mateus Freitas Silveira³, Talyta Lins Nunes⁴, Maria Gláucia Carlos de Oliveira⁵, José Ernandes Rufino de Sousa⁵, Valéria Veras de Paula⁵

Affiliations

¹ Department of Animal Science, Federal Rural University of the Semi-arid Region (UFERSA), 59625-900, Mossoró, RN, Brazil. Electronic address: debora_ufersa@hotmail.com.
² Department of Animal Science, Federal Rural University of the Semi-arid Region (UFERSA), 59625-900, Mossoró, RN, Brazil. Electronic address: jjosielborges@hotmail.com.
³ Department of Animal Science, State University of Valley Acaraú (UVA), 62040-370, Sobral, CE, Brazil. Electronic address: robsonmateus1994@hotmail.com.
⁴ Department of Anatomy, Pathology and Clinics Veterinary, Federal University of Bahia (UFBA), Salvador, BA, Brazil.
⁵ Department of Animal Science, Federal Rural University of the Semi-arid Region (UFERSA), 59625-900, Mossoró, RN, Brazil.

PMID: 32479388
DOI: 10.1016/j.jtherbio.2020.102593

Abstract

The objective of this study was to evaluate the thermoregulatory responses, acid-basic and electrolytic equilibrium of locally adapted goats under natural heat conditions in a semi-arid region. Ten (10) Canindé goats aged between 2 and 3 years, non-lactating, non-pregnant and having a body weight (B_W) of 22.90 ± 2.70 kg were used in this study. Air temperature (A_T) and relative humidity (R_H) were measured, and the radiant heat load (RHL) was subsequently calculated. Rectal temperature (R_T), respiratory rate (R_R), sweating rate (S_R) and heat shock (S) were recorded at 1-h intervals for 24 continuous hours. Hydrogen potential (pH), partial pressure of carbon dioxide (PCO₂), partial pressure of oxygen (PO₂), bicarbonate (HCO₃), base excess (BE), total carbon dioxide concentration (TCO₂), oxygen saturation (SO₂), sodium (Na⁺) and potassium (K⁺) were recorded at three moments during the day (5 a.m.; 1 p.m.; 6 p.m.). There were also significant differences between the means of hours of the day for A_T and R_H. R_R was the thermoregulatory response which most closely followed RHL, with important elevations in the periods between 10 a.m. to noon. It was observed that the goats activated their SR mechanism before R_R, more precisely between the hours of 9 a.m. and 1 p.m. The acid-base and electrolytic equilibrium for the goats which showed great association with the first components contributed the most to the total variation of the data. The most important variables in the adaptive profile of these animals in order of importance were: SO₂, PO₂, R_R, R_T, S_R, HCO₃, BE, TCO₂ and pH. An association between all variables grouped in each period was observed, where the thermoregulatory responses in the periods of 5 a.m. and 6 p.m. were closer than when compared to 1 p.m., showing a physiological return to the initial state. Therefore, the variation in thermoregulatory responses, acid-base and electrolytic equilibrium indicated that the goats have the ability to recover after a challenging environmental condition.

Keywords: Adaptation; Analysis; Blood gas; Canindé goats; Daily rhythmicity; Heat stress; Multivariate.

MeSH terms

Acid-Base Equilibrium*
Animals
Body Temperature Regulation / physiology*
Goats / physiology*
Heat-Shock Response / physiology*
Respiratory Rate
Water-Electrolyte Balance*