The passage of spermatozoa through the cervix of ovariectomized ewes treated with progesterone and oestrogen.

Thirty spayed ewes were used in a 2 x 3 split-plot factorial experiment (n = 5) in which oestrus was induced with 30 or 90 mug oestradiol benzoate (OB) following a period of progesterone priming. They were inseminated 36 hr after oestrogen and the numbers of spermatozoa in the caudal, mid- and cranial regions of the cervix (sub-plots) were estimated 1, 12 and 24 hr later. At each interval of time and for each region of the cervix, fewer spermatozoa were recovered from the ewes treated with 30 mug OB than from those treated with 90 mug (P less than 0-05).