The study was conducted on twelve normally calved, suckled, lactating Murrah buffaloes, aged 57.9±3.2 months from 1st to 3rd parity. The animals varied from 12 to 30 days postpartum at the start of experiment and suckling was restricted to twice daily (before milking). The objective of the study was to monitor ovarian follicular changes during early postpartum in Murrah buffaloes using a real time Bmode ultrasonography. Only 3 out of 12 animals showed cyclicity during observation period. Large follicles (8 to 10 mm) were detected for the 1st time at 24.4±1.99 days, whereas 10 mm follicles were first noticed at 26.0±1.41 days. The duration of growth of dominant follicle (9.3±0.48 days) was higher than duration of its regression (7.1±0.40 days), thereby indicating that the rate of regression is faster (0.73±0.03 mm/d) as compared to rate of growth (0.64±0.02 mm/d). The duration of growth of corpus luteum formed after 1st ovulation was very short (8.67±1.44 days). The largest diameter attained by first postpartum ovulatory follicle was 13.0±1.10 mm and the calving to first postpartum ovulation interval was 52.67±8.02 days in the present study. It is concluded that very few (25%) buffaloes experience ovulations in early postpartum period (within 2 months postpartum). Low number of buffaloes displayed spontaneous resumption of postpartum cyclicity although ovaries of all the animals exhibited follicular activity.

The aim of the present study was to test the efficiency of estrous induction in the premature, metestrous and anestrous bitches. The estrus was induced with prostaglandin F2 alpha, estradiol-17 beta, pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (HCG) in the treatment A, and with PMSG and HCG in the treatment B. Day 0 was the first day of estrone injection in the treatment A and the day of PMSG injection in the treatment B. Twenty three of the twenty six bitches laparotomized under general anesthesia between 11 and 18 days after onset of behavioral estrus, whereas three bitches were not laparotomized and remained until parturition. Ovarian responses were evaluated with the total number of corpora lutea or ovulation sites. The uterine horns were flushed with phosphate-buffered saline added heat treated canine serum (10 %), the flushing media was collected into watch glass and the ova were examined under stereomicroscope. Standing estrus was observed on the day 17.7 +- 1.5 after injection of estrone in the treatment A, but ovarian responses were not detectable. Standing estrus was observed on the day 12.2 +- 0.2 after injection of PMSG in the treatment B and 14 of 17 bitches showed ovarian responses. Ova were recovered in 9 of the 14 bitches. Ovarian responses were observed in one of the three premature bitches, two of the three metestrous bitches and all of the 11 anestrous bitches. The average number of the ova collected from 9 bitchs were 12.2 +- 1.4. Three bitches in the treatment B exhibited behavioural estrus and all of them were mated with fertile male dog, resulting the pregnancy in only one bitch. The pregnant bitch gave the birth of two pups

Determination of the optimum parameters of cattle embryos production in vitro from high-producing cows after their slaughter on a meat-packing plant was realized in the conditions of the Republic of Belarus. Oocyte cumulus complexes of cows of black-motley breed and the conditions of their maturing were used as the object of experimental research. Oocyte cumulus complex were allocated with dissection of ovaries tissue placed into Hanks culture medium. The search and morphological estimation of quality of received oocyte cumulus complexes were realized by microscopic research. Then, the oocytes were placed into a culture medium for cell maturing in СО2-incubator at 38,5 deg C with the maximum humidity (98%), with presence of 5% СО2 under a layer of mineral oil for 24 hours. Matured oocytes were impregnated with the frozen-thawed sperm after capacitation. Oogenesis efficiency of production of pre-implantation germs in vitro was determined in accordance with the level of embryonic fission and production of viable germs. Use cumulus cells monolayer made it possible to increase the quantity of ripened oocytes on 5,2-5,7%, level of embryonic fission - on 14,0-14,6% and production of embryos - on 13,8-12,5% depending on a way of its production in comparison with groups of the cells which were cultivated without a monolayer. Thus, the research has shown the exploitability of use of cellular reproductive technologies in selection and breeding activities in cattle breeding. Their application in combination with embryo transplantation could make it possible to use the reproductive potential of high-priced oocyte donors more effectively for the genetic improvement of animal population efficiency