Characteristics and functions of a minor FSH surge near the end of an interovulatory interval in Bos taurus heifers

Abstract The apparent function of a minor FSH surge based on temporality with follicular events was studied in 10 heifers with 2 follicular waves per interovulatory interval. Individual follicles were tracked from their emergence at 2 mm until their outcome was known, and a blood sample was collected for FSH and LH assay every 12 h from day −14 (day 0=ovulation) to day 4. A minor FSH surge occurred in each heifer (peak, day −4.6 ± 0.2). Concentration of LH increased ( P P P P