Chromium carbochelate dietary supplementation favored the glucocorticoid response during acute inflammation of Piaractus mesopotamicus

•Cr3+ supplementation resulted in the reduction of cortisolemia and glycemia.•Lymphocytes and thrombocytes in the exudate increased by Cr3+ supplementation.•Chromium carbochelate favored the glucocorticoid response during acute inflammation.

This study was performed to investigate the effect of food supplementation with chromium carbochelate on cortisolemia, glycemia and unspecific acute inflammation of pacus (Piaractus mesopotamicus) challenged by inactivated Aeromonas hydrophila in the swim bladder. 120 pacus (80.5 ± 11.3 g) were randomly distributed into 24 tanks (310 L, n = 5). After the adaptation period, the pacus were fed diets supplemented with 0 (control), 12, 18 and 36 mg of chromium carbochelate/kg of dry diet for 90 days (ad libitum). Fish fed diets containing 18 and 36 mg of Cr·kg− 1 resulted in a reduction of cortisolemia and glycemia, and in an increase in the inflammatory response, seen through the greater accumulation of lymphocytes and thrombocytes. These results together suggest that food supplementation with chromium carbochelate, at the concentrations of 18 and 36 mg·kg− 1 of feeds, brought homeostatic benefits to P. mesopotamicus. These benefits were translated, at least partially, as reductions in the consequences from inflammatory stress, with diminished cortisolemia and glycemia, which favored accumulation of lymphocytes and thrombocytes at the affected focus, as an increase in the immune response.