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Performance and reproduction of Holstein cattle
KAMENÍKOVÁ, Jana
The aim of thesis was to analyze the milk efficiency and fertility of dairy cows of Holstein cattle breeding under intensive conditions. The examinations were made in the agricultural company ZDV Krchleby, a.s. during the year of 2007 to 2009. In total, 147 dairy cows were used for observation including 35 Holstein dairy cows (100% H, R 100%), in a group called - H1, 70 Holstein cows crossed with Czech spotted cattle (H 75 - 87%, R 75 - 87%) in group - H3 and 42 Holstein cows crossed with Czech spotted cattle (H 50 - 74%, R 50 - 74%), in group - H4. Furthermore, the basic data set was divided according to lactation into four groups: 1st lactation, 2nd lactations, 3rd lactations, 4th and more lactations. The main indicators for evaluation of the milk efficiency were the: milk quantity (kg), amount of fat in the milk (%), production of the fat in the milk (kg), amount of protein in the milk (%), production of protein in the milk (kg), content of lactose in the milk (%), persistency of lactation and lactation duration (in days). In terms of fertility, the following factors were evaluated: the cow?s age at first birth (in days), insemination interval (in days), service period (in days) and the periods between births (in days). The cows in the first group milked on average of 8945.03 kg of milk, the amount of fat was 3.66%, the content of protein was 3.32%. Cows in the second group milked an average amount of 8186.55 kg of milk, the content of fat was 3.77%, the amount of protein was 3.33%. The third group milked an average amount of the milk 8649.05 kg, the content of fat was 3.58% and the amount of protein was 3.26%. Differences between these groups were not statistically significant. From the reproductive indicators, statistically, the only most significant difference was the time in between births. The longest period in between births was measured in the first group - 576.22 days, in the second group - 487.38 days and in the third group - 480.95 days.
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