Effects of progesterone or estradiol on uterine tubal transport of ova in the cow.

An experiment was designed to determine the effect of progesterone (P) or estradiol benzoate (EB) on uterine tubal transport of ova in the cow. Intramuscular injections of P, EB, or corn oil (C) were administered to heifers 24 hours after the end of estrus. The heifers were euthanatized 60 hours after the end of estrus and the location of the ovum or zygote was determined. Venous serum levels of progesterone and estradiol-17beta were measured by radioimmunoassay. The mean uterine tube (UT) length was 23.9 cm. An ovum or zygote was recovered from 11 of 14 heifers. Serum levels of progesterone and estradiol-17beta were above normal bovine levels following the P and EB treatments, respectively. The mean UT ovum transport rates were 0.42, 0.21 and 0.23 cm/hour in the P, EB and C treatment groups, respectively. The UT ovum transport rate was increased (P<0.05) by the P treatment and EB treatment had no effect (P > 0.05) when compared with the C treatment.