The aim of this thesis is to evaluate chosen influences on the extent of reproduction of randomly chosen milk cows that are bred in the same conditions. The chosen influences such as breed, age of the first calving, time of year of calving and level of yield were observed within breeds of Czech Fleckvieh and Holstein cattle. Evaluation was carried out in ZOD "Podhradí" Choustník company, specifically in Budislav farm. 191 cows were chosen for the basic sample. 95 of them were Holstein cattle and 96 were Czech mottled cattle. Chosen influences were evaluated according to data gained from the set of milk yield inspections. A statistically significant difference was observed between Czech ticks and Holstein cows in the length of service period per second and first lactation where Holstein cows have a second lactation period longer than 44 days (P <0.001). Evaluation of first calving age did not show any influence on the level of reproduction neither within Czech Fleckvieh nor within Holstein cattle. During the annual evaluation, it emerged that Holstein cows calved in spring and winter have significantly bigger insemination interval compared to cows that were calved during summer or autumn. This fact was also proven by correlation analysis. This analysis also confirmed the relation between annual period and insemination interval Rxy=0,21(P<0,05). The correlation analysis also proved the relation between annual period and service period as well as interim of Czech Fleckvieh cattle Rxy= 0,327 (P<0,01). Statistically significant influence was not proven within Holstein cattle. Correlation analysis only pointed out the relation between yield and service period Rxy=0,213 (P<0,05). Unlike Holstein cattle, gradual increase of service period figures and interim depending on yield was noticed. Breeding cows milking more that 7,5 thousand kg of milk per lactation had service period of 132 days (P<0,01) and interim 407 days (P<0,01). Economical losses caused by prolonged interim during monitored herd of cattle reached 400.490 CZK in year of 2016.