[Study of the influence of some factors on conception and fertility rates in sheep in the anestrus period].

Experiments were carried out with a total of 520 sheep, two-breed crosses, during the anestrus period (January-May) in 1972 and 1973. Estrus was induced by means of hormonal preparations, such as implants (Silestrus), vaginal swabs (Veramix), pregnant mare sera (Rigaoux) as well as estradiol-valerianat. Both the test and the control groups of animals were divided into four lots to study: a. the effect of the interval following lambing and the season on the results of hormonal treatment; b. the conception and fertility rates in lactating ewes with weaned lambs in the anestrus period; c. the effect of hormonal treatment in young and adult ewes nursing single lambs or twins and d. the influence of the functional status on the results of hormonal treatment.