Cortisol Concentrations in Hair, Blood and Milk of Holstein and Busha Cattle

Abstract

Cortisol levels were measured in hair, blood and milk in two different cattle breeds, kept under different breeding conditions and with different genetic merit for milk production. Cows and heifers of Holstein and Busha breeds were selected for the study. Cortisol concentration was determined by immunoassays. Cortisol accumulation was determined in proximal (close to the skin) and distal (far from the skin) segments of the hair shaft. The influence of hair colour and washing prior to extraction and analysis was also examined in order to establish additional factors that may have an impact on hair cortisol concentrations. Concentrations of cortisol determined in the proximal and distal segments of the shaft were significantly higher in Holstein than Busha cows and heifers (P<0.05 and P<0.01, respectively). In Holstein cows, no significant difference was found between concentrations in black and white hair. In hair washed with isopropanol, cortisol concentration was significantly lower compared to unwashed hair (P<0.01). Thus, cortisol concentration in hair varies with the technique of hair processing (washing), but not with colour in Holstein cows. Blood serum cortisol concentrations in Holstein cows and heifers were significantly higher than in Busha cows and heifers, (P<0.01 and P<0.05, respectively). Milk cortisol in Holstein cows was significantly higher than in Busha cows (P<0.05). The higher cortisol concentrations in Holstein cows are assumed to be the result of intensive breeding and physiological adaptation to high milk production.

Sheep wool cortisol as a retrospective measure of long-term HPA axis activity and its links to body mass

“…The majority of studies conducting segmental hair analysis found no difference between segments [7,9] or measured lower cortisol concentrations in segments more distal from the skin [8,18,22,66], potentially due to the 'wash-out effect' (see [15]) or diffusion from areas of high to low cortisol concentration [7]. Neither mechanism can explain the opposite effect, i.e.…”

“…Washing of hair samples was introduced to remove any glucocorticoids that may have been deposited externally on the hair through contact with sebum and sweat [7,25]. A number of studies have validated the washing process with regards to the optimum washing solvent (methanol, isopropanol) and the number of wash cycles [7,18,54]; however only one study on cattle, to date, has directly compared cortisol concentrations of washed and unwashed hair samples and found higher concentrations in unwashed samples, suggesting that washing does indeed remove external glucocorticoids [22]. Surprisingly, we found the opposite effect in the present study -cortisol concentrations were slightly but significantly higher in washed compared to unwashed wool samples (see Figure 3B).…”

“…In recent years, hair cortisol analysis has become a commonly used tool for the retrospective assessment of long-term HPA axis activity in numerous mammal species, including, for example, non-human primates [7,[8][9][10][11][12][13], humans [14,15,16], carnivores [17][18][19][20], ungulates [21,22], lagomorphs [23], rodents [24] (for reviews see e.g. [25,26]).…”

Preventing ectoparasite infestations reduces glucocorticoid concentrations in the hair of cows – short communication

“…The samples were stored at -20 °C until analysis. Prior to the measurement cortisol and corticosterone were extracted from the hair with methanol as described by Nedić et al (2017). Cortisol and corticosterone concentrations in the hair extracts were determined using commercial ELISA kits (Demeditec, Kiel-Walsee, Germany).…”

“…Cortisol and corticosterone concentrations in the hair extracts were determined using commercial ELISA kits (Demeditec, Kiel-Walsee, Germany). Partial validations of hair cortisol and corticosterone detection were performed (Nedić et al, 2017).…”