Abstract
Ketosis can exist in both clinicla and subclinical forms. Detection of the subclinical form of ketosis by the use of a nitroprusside based test powder gas been shown to be a relatively simple and reliable procedure. Howere, very liffle is known about the indcidence or prevalence of the subclinical ketosis in Korea. In the present study, samples of urine taken from 288 dairy cows in Chonnam area were examined to demonstrate the presence of ketone bodies, using ross test. All the cows were within 4 weeks either before or after parturition. The gerd size was from 10 to more than 100 cows, and the cows did not show any clinical signs of ketosis. Of the 288 cows, 85 (29.5%) were positive to Ross test; of the positive cases 42.4% were +, 44.7% were ++, and the remaining 12.9% were +++. The prevalence increased from 3rd parity, peaked at 6th parity and thereafter decreased. The prevalence was higher after parturition than before parturition, with the highest occurrence during the 2nd week after calving. The prevalence was higher during winter. Also cows kept indoor throughout the year showed higher occurrence of the subclinical ketosis. The subclinical ketosis did not affect the specific gravity of the urine; however, increasing amount of ketone bodies in the urine decreased the pH of urine.