Abstract
<title>Abstract</title> <p>The blood and follicular fluid metabolic profiles and their correlation with the quality of aspirated oocytes were studied at different periods after parturition in primiparous F1 Holstein x Gir lactating cows. Follicular aspirations were performed on 29 F1 Holstein x Gir crossbred heifers on days 30 ± 2, 60 ± 2, and 100 ± 2 after parturition. On the same days as oocyte collection, blood and follicular fluid from the dominant follicle were collected for glucose, NEFA, BHBA, and urea assays. Oocyte recovery rates, in vitro maturation rates, and apoptosis rates were evaluated. The average glucose concentration on day 30 postpartum was higher in follicular fluid compared to blood plasma. Urea concentrations in plasma and follicular fluid did not differ between days 30, 60, and 100. For BHBA and NEFA, no difference was observed between the concentrations in follicular fluid and blood serum between days 30, 60, and 100 postpartum. There was no difference in the oocyte recovery rate between collection times; however, it was observed that collections performed on days 30 and 60 showed a lower percentage of viable oocytes. No difference was observed in TUNEL negativity between the analyzed times; however, it was evidenced that oocytes collected on day 30 postpartum showed a higher maturation rate compared to those collected on day 100. It is concluded that primiparous F1 Holstein x Gir cows, from 30 days postpartum onwards, have the capacity to enter reproductive routine, as they present oocytes of quality even in an earlier postpartum period.</p>