[Comparative studies of hormonal methods for affecting the reproductive functions of cows being raised by different technics].

Studied was the effect of two raising technologies in the industrial rearing of cows (tied and loose housing) along with the effect of the use of hormonal-and-stimulating therapy on their reproductive functions. It was found that the duration of the service period with the two technologies without using hormones was considerably long (respectively 124.3 +/- 7.8 up to 133.0 +/- 5.1 days, and 138.5 +/- 8.1 up to 144.0 +/- 3.3 days). The rate of conception at first insemination with tie-up housing varied from 20.23 to 56.67 per cent, and the total conception--from 74.41 to 86.67, whereas the fertilization of a cow required 2.35 to 2.77 doses of semen. At loose box housing the conception rate varied from 25.13 to 47.69 per cent and 75.15 to 84.61 per cent, and the used doses of semen were 2.40 to 2.69. Treatment with gravohormon between the 40th to 60th day following calving raised the total conception and the conception at first insemination--54.70 and 94.70 per cent at loose box housing, and 62.65 and 95.18 per cent at tie-up housing. Combined hormonal treatment with gravohormon and oroestron within the interval of the 100th-160th day following calving with the two technologies led to the very high clinical manifestation of the estrus, however, it did not raise the conception rate. Treatment with estrumate between the 100th and the 160th day after calving produced a higher effect with regard to conception as against the combined treatment with gravohormon and oroestron. The stimulating hormonal therapy had a higher effect on the conception at first insemination with the technology of tie-up housing.