Effects of dietary chromium supplementation on glucose tolerance and primary antibody response against peste des petits ruminants in dwarf Bengal goats (Capra hircus)

Abstract

An experiment was conducted to exploit the immune-modulation effect of trivalent chromium (Cr) for augmenting immunity against peste des petits ruminants (PPR) in dwarf black Bengal goats (Capra hircus). The goats (n = 6 per treatment group) either received a basal diet devoid of supplemental Cr (control) or were supplemented with 0.5 mg Cr as chromic chloride (+Cr) for 60 days. Live weight gain and feed conversion efficiency improved (P < 0.05) in the +Cr dietary group. Supplemental Cr did not affect the total number of monocytes, eosinophils and basophils (P > 0.1) although total leukocytes increased (P < 0.05) and the ratio of neutrophils to lymphocytes narrowed down (P < 0.05) in the +Cr dietary group. The effect of Cr supplementation on variables of the intravenous glucose tolerance test (IVGTT) was inconclusive. Compared to the control group, the basal concentration of glucose (P < 0.05) and insulin (P < 0.001) was higher, clearance rate was slower (P < 0.05) and serum half-life was greater (P < 0.05) in the +Cr dietary group during the IVGTT. Over the duration of the experiment, serum concentration of insulin increased (P < 0.001) and that of cortisol decreased (P < 0.01) in the +Cr group, which also showed a relatively higher primary antibody (Ab) response against PPR on days 10 (P < 0.01) and 20 (P < 0.05) post-vaccination. In conclusion, the experiment indicated that supplementation of Cr as CrCl3, in the diet of non-stressed goats, may improve primary Ab response against PPR and help confer an augmented immunity to the disease besides promoting growth and feed conversion.