Effect of chromium picolinate supplementation before weaning on the hematological profile, behaviour and weaning stress in piglets

Weaning is one of the most critical periods in pig production, inducing profound physiological, metabolic, immunological and behavioural changes that may adversely affect piglet welfare and performance. The present study evaluated the effects of early chromium picolinate supplementation on hematological and biochemical blood parameters, differential leukocyte counts, behavioural responses and physiological adaptation to weaning stress. Thirty-two piglets originating from eight sows were allocated to a control group and an experimental group (16 animals each). Piglets in the experimental group received 200 μg chromium picolinate per animal per day, starting five days before weaning and continuing until the third day after weaning, whereas the control group received the basal diet only. Blood samples were collected before supplementation, on the day of weaning and at the end of the experimental period. Behavioural observations were performed during the first two days after weaning. Chromium picolinate supplementation did not significantly affect glucose concentration or the main hematological indicators (P>0.05). A significant additive effect was observed for eosinophils (P = 0.030), while the sampling period significantly affected glucose, leukocyte, erythrocyte, banded and segmented neutrophil, and lymphocyte values. During the first post-weaning day, supplemented piglets showed lower locomotor activity and longer resting and feeding times than controls. These findings suggest that supplementation initiated before weaning may support behavioural adaptation and help moderate selected stress-related changes without adversely affecting hematological homeostasis.