Evaluation of homeothermy, acid-base and electrolytic balance of black goats and ewes in an equatorial semi-arid environment

Josiel Ferreira; Robson Mateus Freitas Silveira; José Ernandes Rufino de Sousa; Angela Maria de Vasconcelos; Magda Maria Guilhermino; Débora Andréa Evangelista Façanha

doi:10.1016/j.jtherbio.2021.103027

Evaluation of homeothermy, acid-base and electrolytic balance of black goats and ewes in an equatorial semi-arid environment

J Therm Biol. 2021 Aug:100:103027. doi: 10.1016/j.jtherbio.2021.103027. Epub 2021 Jun 8.

Authors

Josiel Ferreira¹, Robson Mateus Freitas Silveira², José Ernandes Rufino de Sousa³, Angela Maria de Vasconcelos⁴, Magda Maria Guilhermino⁵, Débora Andréa Evangelista Façanha³

Affiliations

¹ Department of Animal Science, Federal University of the Semi-arid Region (UFERSA), 59625-900, Mossoró, Rio Grande do Norte, Brazil. Electronic address: jjosielborges@hotmail.com.
² Luiz de Queiroz College of Agriculture, University of São Paulo (USP), Department of Animal Science, Piracicaba, São Paulo 13.418-900, Brazil.
³ Department of Animal Science, Federal University of the Semi-arid Region (UFERSA), 59625-900, Mossoró, Rio Grande do Norte, Brazil.
⁴ Department of Animal Science, State University of Valley Acaraú (UVA), 62040370, Sobral, Ceará, Brazil.
⁵ Federal University of the Rio Grande do Norte (UFRN), 59078970, Rio Grande do Norte, Natal, Brazil.

PMID: 34503774
DOI: 10.1016/j.jtherbio.2021.103027

Abstract

The aim of this study was to investigate the influence of environmental conditions and species on thermoregulatory responses, acid-base and electrolyte balance of black goats and ewes in an equatorial semi-arid environment. Ten Canindé goats and seven Morada Nova ewes with black coat color, all multiparous, aged between 2 and 3 years, non-lactating, non-pregnant, and body weight (B_W) of 22.84 ± 4.17 kg for goats and 22.60 ± 3.18 kg for ewes were used in this study. Air temperature (A_T) and relative humidity (R_H) were measured. Respiratory rate (R_R), Rectal temperature (R_T), sweating rate (S_R), hydrogen potential (pH), partial pressure of carbon dioxide (PCO₂), venous oxygen pressure (PO₂), bicarbonate (HCO₃), base excess (BE), total carbon dioxide concentration (TCO₂), venous oxygen saturation (SO₂), sodium (Na⁺) and potassium (K⁺) were recorded. Animal species (caprine and ovine) and environmental conditions (Thermoneutral condition, T_C and Heat condition, H_C) were considered as fixed effects. Univariate and multivariate analysis techniques were used. Differences were observed between the two environmental conditions. Significant changes in all thermoregulatory responses for goats and ewes were observed according to the environmental condition effect. The general means of the species showed that only S_R was high in ewes (P < 0.05), following a reverse change when compared to goat S_R. For the environmental condition effect, only the blood pH of goats did not change under H_C (P < 0.05), while the B_E and TCO₂ did not change for ewes. The general means of PCO₂, HCO₃, BE, TCO₂ and SO₂ were higher in ewes compared to goats. For electrolytic balance, Na ⁺ demonstrated elevations in H_C. Brazilian black goats and ewes raised in an equatorial semi-arid environment tend to have particular homeothermy, acid-base and electrolytic balance which mostly depend on the environmental conditions they are raised. The results support the changes in physiological mechanisms between black goats and ewes; however, both are locally adapted.

Keywords: Adaption; Black hair; Blood gas; Canindé goats; Locally adapted animals; Morada Nova ewes.

MeSH terms

Acclimatization*
Animals
Body Temperature Regulation*
Female
Goats / physiology*
Hot Temperature
Humidity
Sheep / physiology*
Water-Electrolyte Balance*