Resumption of ovarian function, the metabolic profile and body condition in Brahman cows (Bos indicus) is not affected by the combination of calf separation and progestogen treatment.

To evaluate the effect of different calf separation procedures after a progestogen treatment on the resumption of ovarian function, body condition and metabolic profile, 59 multiparous Brahman cows grazing on a mixed grass pasture were studied. No supplementation was given at any time. Body condition score (BCS), fat thickness (FAT) and blood metabolites were measured fortnightly from the beginning of the last trimester of gestation until 96days postpartum. At 30days postpartum all animals received a progesterone (P4)-releasing device (CIDR) which was withdrawn 9days later when prostaglandin F2α was applied. At this time, treatments TW (n=28), where calves were separated from their dams for 48h; RS (n=21), calves were allowed to suckle once a day for 1h; and continuous suckling (CS; n=10). Ovarian function was assessed by blood concentrations of progesterone on days -14, -9, 10, 13, 30 and 33 after CIDR removal. At the end of the experimental period, an average of 20% of the cows had not initiated estrous cycles. There were no changes of FAT or BCS during the last trimester of pregnancy in all cows (P>0.05). During the postpartum period cows of all groups lost (P<0.05) BCS and FAT with a nadir at 60-80days postpartum, regardless of treatment. At 10days after CIDR withdrawal the percentage of cows having ovulations was 75, 61 and 80 (P>0.05) for TW, RS and CS groups. Blood metabolites follow a similar pattern in the three groups. With the conditions of the present study, the method of calf separation after a progestogen treatment, does not affect the resumption of ovarian function or metabolic profile.