NUMBERS OF SPERMATOZOA IN THE GENITAL TRACT AFTER ARTIFICIAL INSEMINATION OF PROGESTAGEN-TREATED EWES

Abstract

Summary. An experiment is described in which spermatozoa were recovered from genital tracts of ewes either at the first oestrus following progestagen synchronization or at a normal oestrus. Recoveries 1, 12, 24, 36 and 48 hr after the insemination of 500× 106 spermatozoa show that synchronization with intravaginal sponges impregnated with the synthetic progestagen 17α-acetoxy-9α-fluoro-11β-hydroxypregn-4-ene-3,20-dione (Cronolone, Searle) alters the numbers and distribution of spermatozoa throughout the female genital tract at the first oestrus after treatment. One hour after insemination the total numbers of spermatozoa recovered, and their distribution between the various regions of the tract, differed little between progestagen-treated and untreated ewes. Thereafter the numbers recovered from treated ewes were significantly fewer than from untreated, and their distribution differed. Significant differences appeared in the vagina at 12 hr and in the cervix and uterus at 24 hr and thereafter this difference was maintained. The pattern in the Fallopian tubes followed that of the uterus. At 24 hr the mean numbers of tubal spermatozoa recovered were: synchronized—900; non-synchronized—8200 (P< 0·001). Both transport and survival of spermatozoa may be deleteriously affected in the reproductive tract of the progestagen-treated ewe.