The aim of the thesis was to evaluate fertility and milk performance in dairy cows, predominantly Holstein cattle, due to technology used in the view of welfare animals. Monitoring was carried out on the farm AGROSPOL, Malý Bor a.s. from 2008 to 2010. Dairy cows were kept in the same technological conditions, with the same level of nutrition and treatment. Monitoring included 662 dairy cows of Bohemian Spotted Cattle (C), Holstein cattle (H1) and high proportion of crossbreeds of these cows (H2). Fertility was evaluated due to indicators of reproduction (first calving age, insemination interval, service period, interim) and in terms of milk performance there were measured indicators of milk production (lactation length, milk production, protein production, fat content, protein and lactose content). Statistically, significant differences were found in the length of insemination interval, service period length (P ? 0,01) and interim length (P ? 0,05). Dairy cows (C) reached markedly shorter period of the following indicators: insemination interval 70,6 days, service period 98,6 days and interim 395,9 days. There was not found a significant difference in length of these indicators among the groups of Holstein dairy cows. Lactation order did not influence the length of reproduction indicators. The influence of bull-father in terms of reproductive indicators was not proved. Comparison of milk production and protein production in dairy cows due to lactation order proved that cows in the first lactation had a lower yield of milk (8737,1 kg) than dairy cows in the following lactations (9669,3 ? 10209,3 kg), as well as protein production (kg). Dairy cows ?C? gave 9115,3 kg of milk in 305 days, dairy cows ?H1? 9664,1 kg and cows ?H2? 9511,0 kg of milk. These differences were not evaluated as statistically conclusive, as well as differences in content of milk elements among genotypes in fixed lactation norms. The influence of the individuality of a bull in milk and protein production was not proved. Significant differences were found in percentage of fat content (P ? 0,05), protein and lactose content (P ? 0,01) in milk of cow-daughters after particular bulls.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:50688 |
| Date | January 2011 |
| Creators | POTUŽÁKOVÁ, Jitka |
| Source Sets | Czech ETDs |
| Language | Czech |
| Detected Language | English |
| Type | info:eu-repo/semantics/masterThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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