Physiological responses in weaned water buffalo calves with different separation strategies

The aim of the present study was to evaluate the effects of three distinct weaning strategies on physiological responses in water buffalo calves. Forty Murrah calves (20 males, 20 females) between 7-8 months of age (229.05 +/- 54 kg) were assigned to one of four groups with ten animals each: NW: non-weaned, AW: abruptly weaned on day 0, NFW: calves fitted with nose-flaps on day -7. At day 0 devices were removed and calves were separated permanently from their mothers, FENW: calves separated from their mothers by a fence-line on day -7. At day 0 calves were separated permanently from their mothers. All physiological indicators; heart rate (HR), respiratory rate (RR), skin surface temperature (SST), rectal temperature (RT), gas exchange, acid-base balance, hydric and mineral balance and energy metabolism were recorded at days -7, -6, -4, 0, 1 and 3. Results show that calves in FENW had higher HR, RR, RT and glucose values (P <0.05) between days -7 and -6 than the other groups, while the AW calves had higher HR, RR, RT, glucose and lactate values between days 0 and 1 (P < 0.05). No changes were found for the effect of group in relation to blood gases, acid-base balance, or hydric and mineral balance (P> 0.05). Study results demonstrate that abrupt weaning by a fence-line in the early postseparation stage generates changes in physiological and energy metabolism possibly associated with the moment of separation from their mothers. The changes found for effect of weaning strategies in the parameters measured could provide a reference for weaned buffalo calves on their physiology.