The aim of this thesi is the evaluation of selected impacts of elimination and longevity of Holstein and Czech spotted dairy cows on the Ing. Bohuslav Vacka´s farm in Vrchotovy Janovice according to the reason of this elimination, the age at the first calving, milk production of the first milk lactation, lifetime milk lactation and the number of milk lactation during the lifetime. I also evaluated functional longevity (from the first calving to retirement) and the longevity of life (from the birth to retirement) of retired dairy cows and the relationship between age at the first calving, milk production of the first lactation and lifetime milk production. In monitoring were included 359 pieces of cows eliminated during five years, from 1 January 2010 to 31 December 2014. From these, 217 pieces of Holstein cows and 142 pieces of Czech spotted cows. Both breeds were stalled in the same barn with the same nutrition. At the monitored group were eliminated altogether 31.22% of dairy cows. Holstein cows were excluded very often from other medical reasons (28.57%) and the Czech spotted cows for fertility disorders (45.77%). Higher milk productivity and higher average number of lactations for the life reached eliminated Holstein cows in comparison with the Czech spotted cows. Longer lifetime longevity reached Holstein cows (63 months) than Czech spotted cows (53.6 months) and among them was found highly significant difference at a significance level of p 0,001. Higher longevity and lifetime milk production in kg of milk reached Holstein cows calved in 25 to 26 months and Czech spotted cows calved within 27 to 28 months. The relationship between age at the first calving and lifetime milk production at Holstein (r = 0.018) and Czech spotted cows (r = 0.0434) proved to be an insignificant dependence and the relationship between milk production at the first lactation and lifetime milk production at Holstein (r = 0.3317) and Czech spotted cows (r = 0.4436) proved to be as a highly significant correlation (p 0.001).

The aim of the work was to elaborate a literary review of the characteristics, reproductive properties of Holstein cattle and influences affecting the reproduction of cattle. Another objective of the work was to evaluate the selected influences on their reproduction in a group of selected dairy cows from the monitored cattle herd. The data were processed and sorted by genotype, level of milk performance, parity, length of dry period, length of insemination interval, difficulty of calving, age of the first calving and synchronization of estrous (Ovsynch). In evaluating the effect of the genotype on reproductive parameters, there were no statistically significant differences between purebred Holstein cows (H100) and crosses (H50-88C). In addition, the effect of milk yield on lactation on reproductive performance was evaluated. The results showed that with increasing performance, the values of reproduction indicators (insemination index, insemination interval and period service) have increased. The statistically lowest insemination index (1.70) and insemination interval (96 days) were detected in cows with a yield up to 8,000 kg. The service period (122 days) was conclusively the lowest in a cow group with a yield of 8,001 to 10,000 kg lactating milk. In contrast, the highest conclusive values of the insemination index, interval and period service were detected in a group of dairy cows with a yield above 12,001 kg of milk. It is further evident from the results that the values of the pregnancy rate after the first insemination increased with the increasing level of milk performance. The lowest value (27.14%) was detected in the group with the highest milk yield (over 12,001 kg of milk). There were no significant differences between the different groups of dairy cows in the evaluation of the influence of parity on the reproduction indicators. Furthermore, the influence of length of dry period was evaluated. The average dry period in the monitored herd was 69 days. The pregnancy rate after the first insemination was better for the group with a dry period over 61 days (40.38%). On the other hand, periods of service and days open values were lower in dairy cows with a dry period less than 60 days (119 and 394 days respectively). The length of uterine involution was also monitored by the length of insemination interval. Most cows in the monitored group of dairy cows (25.29%) were first inseminated 66th - 87th day after calving. No statistically significant differences were detected in the assessment of the age of the 1st calving and the severity of births on reproductive parameters. The use of controlled reproduction methods (Ovsynch) was also monitored and applied only in the case of reproductive disorders of dairy cows. In the monitored period, Ovsynch was used in only 10 dairy cows and the average service period was 140 days.

This thesis deals with the evaluation of selected influences on the milk production and fertility of dairy cows in a herd of Holstein cattle. The cattle husbandry sector, in recent years, has been facing a worsening of the indicators of reproduction and longevity in dairy cows. It is primarily the requirement of constantly increasing the milk yield of dairy cows that has had an adverse impact on these indicators. The worsening of these indicators can result in a reduction of the cost-effectiveness of the production of milk and meat. The evaluation of influences on milk production and fertility in a herd of Holstein cattle was carried out at the AGRODAM Hořepník s.r.o. company. The selected influences included milk yield quantity, parity, age at first calving, calving interval, insemination index, and conception rate after first insemination. Two hundred and two Holstein dairy cows were included in the monitoring. Data on milk yield and reproduction were obtained from milk yield records and zootechnical records. The results showed that milk production of the monitored group of dairy cows was at a high level (10,025 kg of milk). The highest milk yield in kilograms of milk during first lactation was achieved by dairy cows that calved at the age of 27 to 29 months (9,335 kg of milk). According to the milk yield during the first lactation, the highest milk yield during three lactations was by dairy cows that had a milk yield exceeding 10,000 kg of milk during the first lactation (35,515 kg). When utilizing the DOUBLE OVSYNCH synchronization protocol, the average calving interval was 412 days, and a higher conception rate after first insemination (43%) was found as compared to the nationwide average in the Czech Republic (34.2%). The average number of culled dairy cows was 32%; from this the highest proportion of culled dairy cows was for other medical reasons (31%). Due to low milk yields, 25% of the dairy cows were culled.