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INVOLUÇÃO UTERINA E ATIVIDADE OVARIANA NA VACA LEITEIRA APÓS O PARTO

1974; Embrapa Informação Tecnológica; Volume: 9; Issue: 7 Linguagem: Inglês

1678-3921

Paulo Graça Araújo, Gélio Nogueira Pizzelli, Mauro Ribeiro de Carvalho, Carlos Alberto Meneguelli,

Reproductive Physiology in Livestock

One hundred and sixty crossbred dairy cows were palpated every five days from 10 to 60 days postpartum to study postpartum uterine involution and ovarian activity. A complete involution was observed in 77.5% of the cows between 10 and 30 days postpartum. The mean interval from parturition to involution was 26.4 days, with a significant difference between primiparas (24.5 days) and pluriparas (28.3 days) cows. Season of the year and level of milk production did not affect the involution time. Fertility, measured by conception rate at first insemination and by the number of inseminations per conception, was not significantly influenced by the time of uterine involution. Ovarian activity was essentially absent up to 10 days postpartum. Yellow bodies or mature follicles were present in 49.3% of the cows palpated prior to 60 days postpartum. The intervals, parturition - first ovulation (29.9 days) and parturition-first estrus (53.3 days), measured to 60 and 100 days postpartum, respectively, was not affected by the season of year. However, the interval, parturition - conception, and the percentage of cows showing first postpartum estrus within a fixed interval were affected by season of year. A postpartum anestrus was observed in 35.8% of the cows. This period was significantly shorter for cow that calved in the summer than for those that calved in the winter.