Non-invasive monitoring of antioxidants and stress in captive Indian leopards

Captive Indian leopards are exposed to different kind of stresses part of which can be alleviated through supplementation of carotenoids. However, invasive monitoring of antioxidants is often pro-act as a stressor itself. Hence, use of non-invasive monitoring of antioxidants and stress would be desirable. However, before recommendation, such non-invasive procedures must be compared with conventional ones. Hence, this experiment was designed to compare the cortisol and total antioxidants (TAA) status measured either in serum or faecal samples.

Three diets were tested on twelve adult leopards (7 M and 5 F, BW ranging from 45-63 kg) in an experiment based on replicated Latin square design comprising of three treatments, three periods and three sequences and four animals in each sequence. The ratio of buffalo meat: chicken carcass was 100:0, 90:10 and 80:10 in groups CON, GI and GII, respectively.

Intake and absolute quantity of carotenoids absorbed increased (P<0.01) with increased level of chicken carcass; however, efficiency of absorption was lower (P<0.05) in GII as compared to other two groups. Faecal concentrations of cortisol decreased (P<0.0001) and TAA increased (P<0.0001) with increased level of carotenoids in the diet. Irrespective of the dietary treatments, concentration of cortisol was lower (P<0.0001) and TAA was higher in faecal as compared to serum samples. Regression analysis revealed positive relationship between serum and faecal sample assay with respect to both TAA and cortisol. Thus, faecal samples could be used to monitor cortisol and antioxidant status in Indian leopards. Assay of faecal samples indicated that replacement of buffalo meat with chicken at 20% in the diet improved the antioxidants and alleviated stress in captive leopards.