Vliv věku při prvním otelení na užitkovost dojnic

Breeding cattle is the most demanding sector in agricultural production. Primarily it is demanding in the economic aspect. Factors influencing the economy are proper reproduction and high milk yield quantity, we include these factors among the main breeding objectives. This thesis deals with the analysis of fertility of dairy cows and milk production of holstein cattle herd. The aim of this thesis was the analysis of data on reproduction and milk yield quantity of dairy cows. The following indicators of dairy cows were recorded: milk yield quantity, the age at first calving, parity, calving interval, service period and sex of unborn calves. 295 dairy cows with finished lactation were observed. The influences of the lactation on the milk yield quantity was statistically significant between the first to the second lactation, the first to the third lactation and the first to the fourth lactation. There is not statistically significant difference between the second to the third and the third to the fourth lactation. The influence of the lactation is not statistically significant to longitude set periods and to calving interval. The longest service period 137,10 days was on the fourth and the following lactation. The longest calving interval 406,35days was on the third lactation. The lowest service period 71,1 days was identified in the dairy cows with the yield of over 10 000 kilograms of milk. The dairy cows with milk yield quantity to 6000 kilograms of milk had the shortest calving interval 343 days. The dairy cows which were first calved at the age of 800 to 900 days had the highest yield quantity 8786,58 of milk. For sexes born calf on dairy cow milk yield quantity was a statistically significant difference in milk yield quantity between dairy cows that gave birth to the bull or heifer (p