Fig. 5.

Duration and timing of the MSP relative to the day of ovulation (day 0) in ovulatory cycles. Asterisks indicate conception cycles; the shaded area indicates the fecund phase. Thick black bars indicate the MSP; thin black bars indicate swelling stage 3; white bars indicate sampling gaps. Female names and cycle numbers are shown on the y-axis. ⁽¹⁾Indicates that this cycle occurred during early lactation. All other cycles occurred > 24 months postparturition