[Effect of dietetic and ethological factors on reproduction in cows]

The application of dietetic and ethologic factors on three cow farms led to the improvement of the reproduction parameters. Basic dietetic factors were the correction of the energy--protein ratio, and the percent of the crude protein in the diet. In so far as the ethologic factors were concerned greatest attention was paid to the organization of work on the farms, the strict observance of the daily regime, and the principle of the herd hierarchy. The "independence period", i.e. the period between the time of calving and the time of the following first estrus dropped by 16, 8 and 10 days, respectively. The conception rate at first insemination rose by 25, 25 and 14.9 per cent, and the impregnation rate up to the 60th day--by 9, 13 and 3 per cent, respectively. Milk productivity increased by 1000 1 for the first two farms and by 300 1 for the third one. The number of calves obtained per 100 cows rose by 13, 14 and 2, respectively.