Thermal comfort indexes and physiological parameters of Santa Inês and crossbreed ewes in the semi-arid

Abstract

The objective of this study was evaluated the thermal comfort indexes and physiological parameters in Santa Inês and crossbreed ewes in Brazilian semiarid. The research was developed at experimental station Benjamin Maranhão, twenty non pregnant female sheep were used, 10 pure and 10 crossbreed (½ Dorper + ½ Santa Inês), averaging 26.7 ± 2.1 kg and with 150 days of age at the beginning of the study and confined in a covered sheepfold. A completely randomized design in a 2 x 2 factorial scheme (two genotypes and two shifts) with four treatments and five repetitions was used. The interior and exterior thermal comfort indexes were, most of the day, above the thermal comfort zone for sheep. The rectal temperature, superficial temperature, respiratory rate and cardiac rate was more elevated in the afternoon, and the Santa Inês animals showed in the mornings low rectal temperature values, as well as superficial temperature, respiratory and cardiac rate when compared to the crossbreed.

Ambience of Sheep Submitted to Different Breeding Environments and Global Temperatures

“…Engenharia Agrícola, Jaboticabal, v.38, n.6, p.829-834, nov./dec. 2018 Although the TA is an environmental factor frequently worked in isolation, for many species of animals, its effect depends on the level of atmospheric activity, with variation in TA in function of RH and wind speed (Oliveira et al, 2013, Furtado et al, 2017, Torres et al, 2017. From the thermal point of view, the inversely proportional behavior of the environmental elements is beneficial, favoring the heat transfer processes via latent, which contribute more effectively to the maintenance of thermoregulatory mechanisms of homeothermic animals, especially in high temperature conditions.…”

“…The thermal comfort zone (TCZ) for sheep is TA between 15 and 30°C and RH between 50 and 70% (Baêta & Souza, 2010;Eustáquio Filho et al, 2011). The amplitude of the TA and RH at certain times is above the TCZ, requiring to the animals to activate thermoregulatory mechanisms for thermal maintenance, facts observed by Oliveira et al (2013), Dantas et al (2015), Furtado et al (2017) and Torres et al (2017).…”

“…The black globe thermometer is used to determine the average radiant temperature, indicating the effects of radiant energy, temperature, relative humidity and air velocity, as a practical mode to quantify the radiant energy components of the environment (Furtado et al, 2017;Torres et al, 2017).…”

“…The globe temperature assists in the determination of the BGHI, but a black body has a greater absorptive capacity of the solar radiation (α= 0.97) (ABNT: 15220, 2005), which may result in BGHI values above the animal comfort condition; however, some physiological activities of the animals are sufficient to provide thermal equilibrium Engenharia Agrícola, Jaboticabal, v.38, n.6, p.829-834, nov./dec. 2018 (Dantas et al, 2015, Furtado et al, 2017, Torres et al, 2017. Therefore, the use of gray globe temperature in obtaining the BGHI can generate more coherent information about the animal conditions, considering the superficial characteristics that promote the thermal changes, such as the animals coat/skin coloration (Dantas et al, 2015), as well as the exposure conditions to thermal radiation, full sun or shaded environments (Oliveira et al, 2013).…”

Adaptability of sheep to three salinity levels in different environments

“…In sheep, Eustáquio Filho et al (2011) observed that temperature of 25 °C and relative air humidity of 65% maximized production and productivity in Santa Inês breed, and animals kept at temperatures above the thermal comfort zone (TCZ) might have difficulty eliminating the excessive load, consequently increasing the rectal and skin temperature (ST) and the respiratory and cardiac rate (Queiroz et al, 2015;Titto et al, 2016;Furtado et al, 2017;Seixas, Melo, Tanure, Peripoli, & McManus, 2017). Thermal stress causes several changes in animal physiology, including a reduction in feed efficiency and intake and disturbances in water, protein, energy, and mineral balance, limiting animal production and reproduction (Marai, El-Darawany, Fadiel, & Abdel-Hafez, 2007).…”