Summary An enteric disease affected 16 ruminating calves. The disease was characterized by a nonspecific, mild to severe diarrhea and wasting. Two calves died during the course of disease. C. hyointestinalis was isolated from 12 to 14 calves. The antibody titers of affected calves to C. hyointestinalis varied from 1 : 20 to 1 : 160. The disease was successfully treated with chloramphenicol. Zusammenfassung Bovine Diarrhoe im Zusammenhang mit Campylobacter hyointestinalis 16 wiederkäuende Kälber erkrankten an einer Enteritis, die durch unspezifische, milde bis schwere Durchfälle gekennzeichnet war. Zwei Kälber starben. In 12 von 14 Fällen konnte Campylobacter hyointestinalis aus dem Kot isoliert werden. Die Antikörpertiter der erkrankten Tiere gegen Campylobacter hyointestinalis lagen zwischen 1 : 20 und 1 : 160. Die Enteritis konnte erfolgreich mit Chloramphenicol bekämpft werden.

In this study, fractional excretions (Fe) of sodium (Na), potassium (K), chloride (Cl), calcium (Ca), magnesium (Mg) and phosphorus (PO 4 ) were examined with the aim to demonstrate interactions between fractional excretions of these electrolytes within each period and relate them to electrolyte metabolism in clinically normal cows at different stages of lactation and dry period. The material of this study consisted of 20 clinically healthy Holstein-Friesian cows of the same age and milk yield. Blood and urine samples were collected on 190-200th, 240-250th and 270-280th days of pregnancy and on days 1-7th, 35-45th and 75-85th after calving, altogether 6 times. An increase was observed in Fe Ca and Fe Mg during the transition from the lactation to the dry period (p < 0.05), and a decrease in Fe Ca (p < 0.05), Fe Mg (p < 0.01) in the 2nd month of the dry period. Fe PO4 and Fe Mg , respectively, increased on levels of p < 0.01 and p < 0.05, while Fe Ca decreased on a level of p < 0.05 after gestation compared to the level before gestation. Fe Na and Fe K showed a decrease of p < 0.001 and p < 0.01, respectively, between the 1st and 2nd months of the dry period, while after gestation this value showed an increase in Fe Na (p < 0.05) and Fe K (p < 0.01). Fe Cl increased significantly (p < 0.05) only from postpartum to the 1st month of lactation. There was a strong positive correlation between Fe Na and Fe Cl in all of the periods. It was concluded that there were significant changes in the Fe of Na, K, Cl, Ca, PO 4 and Mg before parturition and during lactation; these changes could have an important role in assessing renal function and electrolyte balance.Key words: Cow, fractional excretion, electrolytes, lactation, dry period Metabolic diseases associated with electrolyte disturbances in cattle, such as parturient paresis (hypocalcaemia), grass tetany (hypomagnesaemia), and displaced abomasum (alkalosis, hypochloraemia and hypokalaemia), develop predominantly before calving or in early lactation and have significant economic impact (Fleming et al