Title:A Keto-TestTM szemikvantitatív tejvizsgálattal megállapított szubklinikai ketosis prevalenciája hazai tejelő tehénállományokban
SUMMARY The authors examined 491 Holstein Friesian dairy cows in the early phase of lactation in order to survey on the prevalence of subclinical ketosis (SK) manifested in ketolactia in Hungarian large-scale dairy herds between September 2013 and February 2014. The tests were conducted during the first 35 days of lactation. The examinations regarding the concentration of beta-hydroxi-butirate (BHB) of the milk were conducted on-site, from whole milk samples at room-temperature, using a colorimetric semi-quantitative test (Keto-TestTM). Different severity of SK (≥ 100 µmol/l milk BHB) was diagnosed in 38% of the examined animals. SK prevalence showed a significant variance in the 8 examined herd (25–57%). The probability of SK with increasing number of lactations showed a non-significantly rising tendency. The milk production of the previous lactation and the size of the herd did not show significant relationship with the odds of SK. In the case of cows suffering from various diseases the concurrent presence of SK could be diagnosed with high prevalence (> 50% on average).