The effect of ram exposure on uterine involution and luteal function during the postpartum period of hair sheep ewes in the tropics

摘要: St. Croix White hair sheep ewes lambing in July (n = 20) or November 26) were used to evaluate the effect of ram exposure on uterine involution and postpartum luteal function. Ewes exposed an epididymectomized (EXPOSED) beginning d 7 after (d 0) kept isolated from rams (CONTROL) through 63. The width each horn was measured using transrectal ultrasonography at 3.5-d intervals within 3 lambing. Jugular blood samples also collected these times, plasma harvested for progesterone (P 4 ) analysis. Days first estrus not different >.10) between EXPOSED that lambed (39.3 ± 3.1 vs 44.2 3.8 d, respectively). Cross-sectional area horns ( P > .10) CONTROL ewes, bearing one two lambs, July. had decreased November. Ram did hasten tropics. Luteal function, determined by concentrations, enhanced during but lack seasonality tropics does seem totally inhibit response exposure.