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.

First lactation milk yield per day of lactation length of 379 Sahiwal cows, collected from cattle breeding farm, Chak Ganjaria, Lucknow were utilized for the present study. The optimum number of progeny size to achieve the accuracy attained by different methods of sire evaluation (Daughter's average (DA), contemporary comparison (CC), Least-squares (LS), Simple Regressed Least-squares (SRLS) and Best linear unbiased prediction (BLUP» ranged from 47.615 (CC) to 161.069 (BLUP). Similar results were also obtained in the ratio ofoptimum progeny size estimated by different methods with that of actual progeny size per sire available ranging from 5.270 (CC) to 17.828 (BLUP). Present findings revealed that BLUP method showed highest increase in accuracy of 207.72% among all the methods studied.

In the conditions of the Republic of Belarus there was realized a comparative estimation of efficiency of the increased level of phosphorus, calcium, copper, zinc, cobalt, iodine and vitamins A and D in comparison with regulations of the All-Union Academy of Agricultural Sciences of the Soviet Union (1985) and the Russian Academy of Agricultural Sciences (2003) for pregnant cows in a dry period at summer feeding. Also, there was studied the digestibility of nutritive substances of forages in cow diets, as well as the evaluation of their after-effect on revelation of dairy productivity indexes in the subsequent two months of lactation, biochemical blood indexes and payment of forage byproducts. As a result of application of moderately increasing levels of macro- and trace elements, vitamin D, and phosphorus in particular on 10,0% in comparison with 15,0% and existing level in rations of pregnant cows there was stated a slight decreasing of pregnancy duration of animals on 0,10 day. Also, there was marked an increasing of milk yield of milk with 4% fat content on 1,64% and 4,48%, the growth and development of calves in the prophylactic period on 4,18 and 4,61%,; and the was an improvement of organic substance digestibility on 1,52 and 1,78%. Besides, there was revealed more moderate number of leukocytes and content of crude protein.

Perfect norms of floor area and feeding front are determined for replacement heifers on free stall management. These norms promote creation of more comfortable conditions of management, increase of average daily live weight gains at 9,1%, hemoglobin content – at 4,8%, erythrocyte quantity – at 6,3%

Balancing of mixed feeds for replacement gilts considering the metabolically energy level and essential available amino acids amount increases growth speed of animals at 9,6% (P less than 0,05) compared to mixed feeds prepared in correspondence with detailed norms of feeding; it also decreases terms of animals pedigree usage from 277 to 223 days