Physiological variables and estimates of heat exchange in sheep kept at thermoneutral and thermal stress temperatures

• Published in: Small ruminant research 2024-08, Vol.237, p.107320, Article 107320
• Main Authors: Silva, Ricardo de Sousa, Furtado, Dermeval Araújo, Ribeiro, Neila Lidiany, Neto, José Pinheiro Lopes, Rodrigues, Raimundo Calixto Martins, Oliveira, Airton Gonçalves de, Silva, José Antônio Pires da Costa, Silva, Maycon Rodrigues da, Mascarenhas, Nágela Maria Henrique, Marques, Jordânio Inácio, Morais, Fabiana Tereza Leal de
• Format: Article
• Language: English
• Subjects: heat stress; heat transfer; Integument; latent heat; Ovis aries; Phenotypic acclimatization; respiratory rate; respiratory system; semiarid zones; sheep; temperature; Thermal insulation
• ISSN: 0921-4488; 1879-0941
• DOI: 10.1016/j.smallrumres.2024.107320

The objective of the research was to quantify the levels of heat stress, physiological variables and losses of sensible and latent heat in sheep native to the Brazilian semi-arid region, kept in a climatic chamber at thermoneutral temperatures and heat stress. The experimental design was completely randomized with five temperatures and 24 sheep, with an average age of 5.0±1.0 months and an average weight of 15.0±2.3 kg. According to the heat stress index (HSI) at temperatures from 20.0 to 28.0 °C the environment was classified as comfortable, at a temperature of 32.0 °C, the environment was classified as mild to moderate discomfort, and at a temperature of 36.0 °C, it was classified as alert. With the increase in temperature, the animals significantly (P