Relationship between thermal comfort indices and internal temperature of grazing lactating Holstein × Gyr cows in western Amazonia

Abstract

The relationship between the indices of thermal comfort and internal temperature in lactating cows was evaluated inRondônia, western Amazonia in a 2 × 2 crossover trial carried out with eight Girolando cows, ½ Holstein × ½ Gyr (n=4) and – Holstein × ¼ Gyr (n=4), grazing palisade grass supplemented with or without soybean oil concentrates. Data logger thermometers adapted to intravaginal devices (hormone free) were used to measure internal temperatures (IT) every 10 min over 48 h. Concomitantly, environmental parameters (air temperature, relative humidity, wind speed, and solar radiation) were collected for the estimation of the temperature-humidity index (THI), equivalent temperature index (ETI), and predicted respiratory rate (PRR). Supplementation with soybean oil did not affect the internal temperature of the cows. IT varied significantly between the genetic groups, with the highest mean observed at night in the – Holstein × ¼ Gyr cows, compared with that in the ½ Holstein × ½ Gyr cows (39.54 °C vs 39.06 °C, respectively). THI, ETI, and PRR were significantly and positively correlated with the IT of the Girolando cows; however, the PRR was not found to be adequate in indicating the night-time heat stress in cows.

Conhecimento local de agricultores familiares sobre árvores nativas em pastagens do Portal da Amazônia, MT

“…A arborização das pastagens tem sido proposta como um meio de fortalecer a sustentabilidade dos sistemas de produção a pasto, o que significa manter em longo prazo a produtividade e a persistência da forrageira, além de contribuir com aspectos ambientais como a formação de corredores ecológicos e incrementar a biodiversidade local (Martinez et al, 2014;Bernardi et al, 2016;Vergne et al, 2016;Carvalho et al, 2018). Estudos indicam contribuições positivas da arborização das pastagens para a melhoria das condições físicas, químicas e microbiológicas do solo e maior crescimento e qualidade das plantas forrageiras (Carvalho & Xavier, 2005;Pang et al, 2019).…”

Efeitos de espécies arbóreas nativas na qualidade e disponibilidade de forragens na Amazônia Mato-Grossense

“…Desta forma, todas as espécies se mostraram com potencial para uso em sistemas silvipastoris. Os dados corroboram com outros trabalhos que indicam importantes contribuições das árvores para manutenção da fertilidade do solo, incremento da biodiversidade local, formação de corredores ecológicos e melhoria da produção e qualidade da planta forrageira (PANG et al, 2019;CARVALHO et al, 2018;BERNARDI et al, 2016;VERGNE et al, 2016;MARTINEZ et al, 2014;CARVALHO et al, 2005).…”

Effect of Amazonian tree species on soil and pasture quality in silvopastoral systems

“…Silvopastoral systems are one of the possible solutions towards a more efficient production system, consisting of an intentional combination of various trees and livestock using different arrangements through time and space (Almeida et al 2013). These systems produce extensive benefits that vary according to local traits and designs, generally including the establishment of biological corridors (Harvey et al 2005;Vergne et al 2016), and improvements to the biological, chemical and physical structure of the soil (Nair 2007;Pinho et al 2012;Martinez et al 2014;), forage quality (Bernardi et al 2016), and thermal comfort of animals (West 2003;Carvalho et al 2018).…”