title: [Experiments to overcome lactation anestrus in dairy sheep].
abstract: An experiment was carried out with three groups of ewes (F1 crosses--Black face Plevenska X East Friesian) used for milk to overcome the lactation anestrus. Use was made of megestrol acetate and PMS during the mating season. The animals of the 1st (control) group were dried off one month prior to the service-period. Those of the IInd group were dried off at the beginning of the insemination period; and those of the IIIrd one were milked during the season and up to the third month of pregnancy. The two test groups of animals were subject to treatment with megestrol acetate and PMS. The conception rate at the first and second insemination of the ewes of the control group was 86.67 per cent, and for the test animals it was 81.25 per cent. Fertility was highest (175 per cent) with the ewes of the second group; it was 166.67 per cent with those of the second and third groups. The energy of growth with the lambs yielded by the test ewes during the sucking period (40 days) was high and almost the same as that with the lambs of the control group. The milking of ewes following impregnation up to the third month of pregnancy at complete-ration feeding did not produce any negative effects on conception and fertility. Neither did it affect adversely the yielding of milk during the following lactations.
mesh_terms: D000780:Anestrus / Q000187:drug effects; D000818:Animals; D003433:Crosses, Genetic; D004971:Estrus / Q000187:drug effects; D005260:Female; D006064:Gonadotropins, Equine / Q000494:pharmacology; D007774:Lactation / Q000187:drug effects; D008535:Megestrol / Q000031:analogs & derivatives / Q000494:pharmacology; D019290:Megestrol Acetate; D011247:Pregnancy; D012098:Reproduction / Q000187:drug effects; D012621:Seasons; D012756:Sheep / Q000502:physiology*; D013997:Time Factors
chemical_list: D006064:Gonadotropins, Equine; D008535:Megestrol; D019290:Megestrol Acetate
vernacular_title: Opiti za preodoliavane na laktatsionniia anestrus pri ovtse ot mlechno napravlenie.