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Výskyt ketóz ve vybraném chovu dojených krav v letech 2020-2022
ŠTĚCHOVÁ, Petra
Ketosis is a disorder of energy metabolism characterised by reduced milk yield, inappetence and weight loss. Ketosis also affects milk composition. The aim of this thesis was to evaluate the incidence of ketosis in a selected dairy cow herd. The incidence of ketosis was evaluated in lactating Holstein cows over a period of three years (2020-2022) in the dairy farm in Žákava. Ketosis was detected on the basis of beta-hydroxybutyrate (BHB) content in the blood of the cows using the FreeStyle Optium NEO device. A BHB value of 1.0 mmol/l or higher was considered as an individual affected by ketosis. A total of 1740 dairy cows were included in the study. Ketosis ocurred at a relatively stable level of 20 %. There were fluctuations in the frequency of ketosis across seasons, as well as fluctuations in the average blood BHB content. The effect of the treatment procedure and the effect of prevention on the incidence of ketosis were also investigated. The treatment success rate was 80.41 % for the study period. Treatment with monopropylene glycol and prodigestane was largely successful. Intravenous glucose administration had a slightly lower success rate. Preventive measures had a positive effect on both the frequency of ketosis and the average blood BHB content. In addition, the presence of ketones bodies in milk, the relation of ketone bodies in blood to ketone bodies in milk and the effect of elevated blood BHB on milk composition were determined according to performance monitoring protocols. Both acetone and BHB contents were increased in milk from sick cows. The levels of ketone bodies in milk are positively correlated with the level of BHB in blood. Increased blood BHB content results in a change of content of individual milk components. The highest difference was found in the fat content, an increase of 4,89 %. Further, the citric acid content increased with the BHB content of the blood and the protein, lactose, non-fat dry matter and urea content decrease.
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