Adaptability of sheep to three salinity levels in different environments

Abstract

The objective of this study is to evaluate physiological parameters and the adaptability of Santa Inês sheep to two climatic conditions 25ºC (within the thermal comfort zone [TCZ) and 32ºC (above the TCZ) and three salinity levels (2.0, 4.0, and 8.0 dS m-1). The study was developed in a climatic chamber using 36 uncastrated male sheep. The experimental design was completely randomized with a 2 ´ 3 factorial scheme composed of two temperatures, three water salinity levels, and six repetitions. The physiological variables were not affected by the salinity levels. The rectal and skin temperature and the heart and respiratory rate were higher at 32 °C. However, the rectal temperature was within the normal range for the species. The consumption of water with different salt concentrations did not affect the adaptive responses of the animals and could be an alternative water source for sheep in regions where water has a high salinity level. The respiratory rate of sheep exposed to 32 °C increased to eliminate body heat, and exposure to 25 °C provided greater thermal comfort for the animals.

Goats in a comfortable and stressed environment consuming saline water: performance, digestibility, nitrogen balance, and urinary mineral concentrations

“…Thus, we observed that the decreased consumption of ethereal extract by goats subjected to a higher temperature can be related to the lower need for production and dissipation of body heat (Wolp et al, 2012). Animals kept in a high temperature environment need to eliminate latent body heat, such as respiration, peripheral vasodilation, and sweating (Furtado et al, 2020). Ribeiro et al (2018) mention that, regardless of breed, environmental variables trigger physiological and behavioral changes in goats to maintain their homeothermia.…”

“…One of the reasons for the increase in this excretion is that the animal organism does not store sodium and its reserves are limited, so excess sodium is quickly excreted in the urine. Potassium is closely related to sodium, and sodium intake in the body is negatively correlated with potassium excretion (Dewhurst et al, 1968), the lower the Na intake, the greater the K excretion. But this did not occur in the present study may be due to the amount of magnesium excreted being close to potassium.…”

“…Different studies indicate that nutrient intake and digestibility can be affected by several factors, such as species or breed of animals (Moura et al, 2016), frequency of intake, and chemical composition of the feed (Moura et al, 2016;Albuquerque et al, 2020), ambient temperature and water salinity levels (Cardoso et al, 2021). In addition, the results also indicate that goats show significant adaptability to saline water intake (Paiva et al, 2017;Furtado et al, 2020;Cardoso et al, 2021), but under penalty of high salt concentration in water can affect dry matter intake by small ruminants and modify mineral metabolism. Therefore, metabolic costs arising from excess salts ingested in drinking water can negatively contribute to the performance of animals and, consequently, for the efficiency of production systems.…”