The results of investigation of the reproductive function of sheep in different periods of year are presented. Ewes was added by clinical (vaginal) examination on 12−14, 21, 30 days after lambing, and also in 2−2,5 months and in an ancestral (non-breeding) period. Researches of the reproductive function in a post-partum period carried out by the estimation of character of secretion from a cervical channel. Material for preparation of vaginal smears was taken away simultaneously. The analysis of smears was carried out after an own method.

Dependence of fertilization in the future breeding season from character of postpartum secret on 11−14 days after lambing was revealed. Depending on character of postpartum secret ewes parted on five groups. The favorable sign on 12−14 days after lambing is a presence in the vagina of viscous mucus with the small admixtures of blood (group III). Fertilization for the ewes of group III in the future breeding season was the greatest − 91,7 % for the first two estrus. For sheep without noticeable secret (I) and with “cheesy chocolate” secretions (V) this index was 67,4 and 62,5 % accordingly.

Lowest fertilization in the first two estrus was for ewes with the turbid smeared mucus with the admixtures of blood and unpleasant smell (II) – 3,3 %; non-fertility − 66,7 %. The sheep which in two weeks after lambing had only remains of dark dry blood had an index of fertility in first heat − 16,6 %, in a second heat − 33,3 %, non-fertility − 50%. To our opinion, high percent of non-fertility in groups I and II caused premature closing of cervix uterus, hypofunction of cervix gland and hypotonia of uterus. Non-fertility in a group 5 could be caused by complicated subinvolution.

At the analysis of vaginal smears of barren ewes of group I every second zoon had 5-10% ‘bare’ nucleus and plenty of leucocytes.

By a citovaginal method on 11−14 days after lambing the physiology indexes of parts of sub-groups of functional epithelial cells were revealed: basal-parabasal (B) − 35−50 %, intermediate cells (M) − 25−35 %, cages of superficial cells (superficial non-keratenosic, S) − 15−30 %. The conditional charts of such correlation have the following kind: B > M > S, B ≥ M > S, sometimes B ≈ M ≈ S and B > M < S.

In three weeks after lambing amount of sheep with insignificant postpartum secret in the area of cervix substantially diminishes and averages 20-25 %. For Merino the amount of such ewes is always greater – to 35 %. On this time the part of sub-groups of functional epithelial cells in vaginal smear the following: basal-parabasal − 30−35 %, intermediate cells − 30−35 %, cages of superficial cells (superficial non-keratenosic) – 30−35 %. Thus marked moderate humidity of mucus shell of vagina in most inspected ewes. Conditional chart of distributing of parts of sub-groups of epithelial cells have the following kind: B ≈ M ≈ S. The amount of destroyed epithelial cells in this time remains high, that testifies to fragility cellular framework, and, to our opinion, is the sign of uncompleteness of involution.

In four weeks after lambing part of sub-groups of functional cages is followings: basal-parabasal epithelial cells − 40−60%, cages of intermediate cells − 18−25%, cages of superficial cells – 20−30%.

At the certain percent of sheep (especially it characteristically for meet-wool and Karakul sheep) through a month after lambing found out distributing of sub-groups of epithelial cells in a vaginal smears which was detected by us as such, that is characteristic for an estral (breeding) period: B < M > S and B < M < S. For cows it was found out the similar distributing on 21 days after calving, that before the display of first sexual heat. After our supervisions the amount of sheep with the foregoing distributing grows in a period from the end of March to the middle of May. Among the gimmers it was found out an estral type anymore as in 50%. To our opinion, it coincides with the spring period of fallowing in ruminant and physiological predefined time of offensive of puberty for young sheep.

After classification of Geyts and Sal'mon in human gynecology types of vaginal smear, what of us discovered in the first two weeks of postpartum period, are the sign of moderate degree of estrogenic insufficiency and weak degree of estrogenic stimulation. From 18−20 days after lambing part of sub-groups of epithelial cells can specify on the offensive of moderate estrogenic stimulation.

In 2−2,5 months after lambing marked dryness of mucus shell of vagina. From a cervical channel it was not found out physiology and pathological excretions by sight. In this period clinical research (external review and vaginal inspection) is not informing. The vaginal smears of sheep are impoverished; the amount of "empty" smears among the inspected sheep arrives at 35 %. Distributing of parts of sub-groups of functional cages in valuable smears specifies on the middle degree of estrogenic stimulation – B ≈ M ≈ S, B < M > S (B > S). Polynuclear neutrophils meet the amount of "+" (after our method) only in third of sheep. In this time the method of vaginal smear is informing enough in relation to the exposure of the hidden inflammatory processes.

In a so-called transitional period of anestral season part of intermediate epithelial cells grows gradually, the amount of superficial cells is synchronously increased here. The amount of destroyed epithelial cells goes down in 2-3 times, for separate sheep this element of smear quite absent. In a transitional anestral period found out the gradual increase of amount of ewes in the vaginal smears of which found out polynuclear neutrophils the amount of "+" and "++". It can testify to strengthening of local immunity before an impregnation. In a transitional period (end of July-August) the chart of distributing of parts of sub-groups of epithelial cells becomes characteristic for an estral (breeding) season.

Conclusions. 1. The best time for the application of vaginal review and application of method of vaginal smear for the exposure of postpartum complications there are 11−14 days after lambing.

2. Through a month after lambing it is set after distributing of sub-groups of functional epithelial cells, that certain part of ewes in flock of Ukrainian breeds of sheep selection partly proceeds in sexual activity without its clinical display. It specifies on possibility and expedience of carrying out of stimulation of the reproductive function in this period. It is thus necessary to take into account a breed, age of ewe and to control the completeness of uterus involution.

3. The found out the features of citological characteristic of vaginal smear in an anestrous specify on that duration of light part of days is a not basic stimulant factor for proceeding in sexual activity of sheep.

4. Consequently at the choice of time and scheme of stimulation of the reproductive function of sheep it is expedient to use the method of vaginal smear.

Кey words: ewe, reproductive function, seasonal, post-partum period, аnеstral season, vaginal examination, vaginal smear, epithelial cells.