Hormonal changes in female buffaloes under shading in tropical climate of Eastern Amazon, Brazil

Abstract

-The hormonal responses of 20 female buffaloes raised under the sun (SS group) or in the shade (CS group) in Belém, Pará, Brazil, were assessed. The CS group (n = 10) was kept in a silvopasture system featuring Racosperma mangium, whereas the SS group (n = 10) was kept in paddocks without shade featuring Brachiaria humidicola, drinking water, and mineral salt. The following parameters were measured for each treatment: dry-bulb temperature (AT), relative humidity (RH), and black-globe temperature in order to calculate the globe temperature and humidity index (GTHI). Blood sample collections to quantitatively determine levels of cortisol, triiodothyronine (T 3 ), and thyroxine (T 4 ) were performed every 14 days, at 13.00 h. Different seasons of the year were also assessed: rainy (January-April), transition (May-July), and less rainy (August-December). Analysis of variance revealed that AT and the index of global temperature and humidity (GTHI) differed between groups; specifically, higher values were found in the SS group, which shows how important silvopastoral systems are in buffalo farming in tropical climates. Relative humidity was significantly different across seasons and particularly high in the rainy season. The treatments influenced cortisol such that higher values were observed in the SS group. The highest mean cortisol levels were recorded during the rainy and less rainy seasons, whereas the highest T 3 and T 4 levels were recorded only during the rainy season. Triiodothyronine and thyroxine were negatively correlated with AT and GTHI and positively correlated with RH. Silvopastoral systems provide thermal comfort to buffaloes, and the less rainy season is more likely to cause heat stress.

Integrating links between tree coverage and cattle welfare in silvopastoral systems evaluation

“…Cortisol in cattle increases with heat (Faure et al 2004). In female water buffalos (Bubalus bubalis) kept in SPSs, lower cortisol levels are present (Silva et al 2014). Broilers have shown more fear-related behaviors when exposed to high temperatures (38 ± 1°C for 3 h) compared to those unexposed (Altan et al 2003), suggesting a relation between cortisol, high temperatures, and fear.…”

Effect of misting and wallowing cooling systems on milk yield, blood and physiological variables during heat stress in lactating Murrah buffalo

“…Neutrophilia and lecocytopnoea i.e. increased neutrophil/ lymphocyte ratio [ 41 , 42 ] was also observed in control animals which attributed to increased glucocorticoids [ 18 , 43 ] mediated alterations in the redistribution of lymphocytes from the blood to other body compartments [ 44 ] during heat stress. At the same time, glucocorticoids also increase an influx of neutrophils into the blood circulation from bone marrow and also reduce the migration of neutrophils from the blood to other compartments [ 45 ].…”

Influence of Temperature Humidity Index and Dietary Energy on Certain Stress Marker Profile of Murrah Buffalo Heifers

“…As in the present study energy content was not limiting or excess in high or low ME group to alter the body homeostasis and major changes in the hormone concentration. Although T 3 concentrations were indicative of energy balance and T 4 appears to be positively associated with energy consumption (Silva et al, 2014). Nowak et al, 2013 reported that serum thyroxin concentration was not affected by medium (0.69 UFL/kg DM) to low (0.61 UFL/kg DM) level energy density diet of dry Holstein cows (UFL is…”