CAN PROLACTIN BE A MEASURABLE MARKER OF STRESS IN DROMEDARIES?

Prolactin, a hormone produced by the anterior pituitary gland, has a well documented role in milk production and several studies have suggested its role in general adaptation syndrome. As dromedaries (Camelus dromedarius) are important animals of arid region, an investigation was carried out in adult dromedaries to assess the role of serum prolactin as a measurable marker of stress. Serum levels of prolactin and cortisol were determined by radioimmunoassay in the healthy and affected dromedaries (those with nasal peg wounds, saddle gall, sand in the third compartment and drought affected). The mean values of serum prolactin (pmol/L) and cortisol (nmol/L) in healthy group were 748.20± 17.82 and 25.93±0.82, respectively. Affected group showed higher levels of serum prolactin and cortisol as compared to healthy group. The mean level of prolactin was 4.94 times higher and cortisol was 4.75 times higher in affected camels as compared to healthy ones. The mean values of different subgroups of affected animals differed significantly and in comparison to healthy male mean value for both serum prolactin (p<0.01) and cortisol (p<0.03). The camels with sand in their third compartments had highest serum levels of prolactin and cortisol. Increase in serum cortisol suggested that affected camels were stressed and simultaneously many fold rise in serum prolactin clearly suggested that it can be a measurable marker of stress in different affections in dromedaries.