Study of the influence of some factors on conception and fertility rates in sheep in the anestrus period
Kostov, L.
Veterinarno-Meditsinski Nauki 12(6): 8-13
1975
ISSN/ISBN: 0324-1068 PMID: 818784 Document Number: 511021
520 sheep were administered Silestrus implants, Veramix vaginal swabs, pregnant mare sera (Rigaoux), and estradiol-valeriant during the anestrous period in order to induce estrus in 1972 and 1973. The effects of the hormonal preparations were studied in 4 groups: the effect of the interval following lambing and the season on the results of the treatment, the conception and fertility rates in lactating ewes in the anestrous period, the effect of the preparations on young and adult ewes nursing lambs, and the influence of the functional status on the results of the treatment. Silestrus implants ( in a dose of 800 IU) substantially raised the conception rate in the January-May period. The most favorable period for applying hormones after lambing was found to be between the 25th-30th day. Higher conception and fertility rates were achieved in nonlactating (82.6 and 140%) and lactating ewes (74.1 and 125%) than in nursing ewes (70 and 125%).