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Faktory ovlivňující reprodukční ukazatele dojnic ve vybraném chovu
ZERZÁNKOVÁ, Veronika
This thesis provides an overview of the literature on reproduction attributes of the Holstein Friesian cattle and its influence on the cattle reproductive indices. One of the goals was to evaluate the influence of selected factors on the reproduction indices for a pre-selected group of dairy cattles. The data has been processed and sorted by the lactation production levels, daily production, order of lactation and the age of the first calving. The data about the used bulls has been processed as well. Another goal of the thesis was acquisition of the data about excluded cows. For the excluded cows, the age, order of lactation, reason for exclusion and life-long production have been recorded. The data for the thesis have been obtained from the production control records and database of breeds in the selected Holstein cattle breeding. The dairy cattles, which got in calf during the years 2017 and 2018 have been evaluated. In particular, for 2017 and 2018, the evaluation was carried out on 190 and 229 dairy cattles respectively, which makes the total of 419 evaluated cows. For those dairy cows, the insemination index data, insemination interval, gestation after first insemination, service period and gestation period has been recovered from the zootechnical register. The evaluation of excluded dairy cows contained 339 dairy cows, which have been excluded during years 2017 and 2018. For the evaluation of the used bulls, the total count and description of how the bull for insemination have been selected is provided. Evaluation the influence of level of lactation production on the reproduction indices has shown a significant (p0,05) statistical relation between production levels and duration of the service period. It has also been proven that this has an influence on the insemination index levels. The lowest values (p0,05) of service period and insemination index have been detected for dairy cattles with production up to 6 999 kg. On the other hand, the highest values of service period and insemination index have been recorded for the dairy cattles with production up to 9 000 kg (p0,05). The influence of daily dairy production levels on the reproduction indices have been evaluated as well. It can be clearly seen from the results that as the daily dairy production increases, the service period increases as well. The lowest values (p0,05) of the service period was recorded for breeds, who had the daily production levels up to 24.99 kg. Opposed to that, the highest values of service period have been recorded for dairy cattles with average daily milk production over 30 kg. The evaluation of order of lactation on the reproduction indices did not show any significant statistical results (p0,05). Furthermore, during the evaluation of first calving, no statistically significant differences have been shown (p0,05). Last reproduction index we have evaluated was gestation after the first insemination. The groups were divided by the production levels, daily milk production, order of lactation and age of the first calving. For each group, the percentage of cattles that got in calf after first insemination has been computed. On average, this value was 36.28%.
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