Effects of Oral Supplementation of Potassium Chloride in Hypokalemic Dairy Cows by Use of a Bolus Formulation on Metabolism, Abomasal Position and Vaginal Discharge Characteristics ; Auswirkungen der oralen Verabreichung von Kaliumchlorid an hypokaliämische Milchkühe mittels eines Bolus auf Stoffwechsel, Position des Labmagens und Beschaffenheit des Vaginalsekretes

Dairy cows that revealed moderate hypokalemia (plasma potassium levels between ≥ 2.8 and < 3.5 mmol/l) when admitted to the animal hospital were by chance assigned either to a treatment group (Group 1a: 19 cows) or to a control group (Group 1b: 17 cows), while all animals with severe hypokalemia (plasma potassium levels < 2.8 mmol/l; Group 2: 11 cows) were treated with potassium for ethical reasons, as they showed severe derailment of potassium homeostasis indicative for a severely impaired general condition. The study animals had been referred to the Ruminant and Swine Clinic, Department of Veterinary Medicine, Freie Universität Berlin for various diseases including abomasal displacement to the left (LDA), ketosis, metritis and mastitis occurring as single entities or in combination. Cows enrolled in the treatment groups (1a and 2) were orally administered potassium in a bolus formulation by use of a balling gun while animals allotted to Group 1b remained untreated and served as controls. The bolus formulation contained approximately 85-91 g potassium chloride and 15-16 g magnesium oxide. Blood samples were obtained for blood gas analysis and the determination of plasma levels of potassium, sodium, glucose, ionized calcium before and at 1, 2, 3, 12, 36, 60 and 84 hours following bolus or sham administration (Group 1b controls), respectively. ß-hydroxybutyrate, aspartate transaminase (AST), alkaline phosphatase (AP), non-esterified fatty acids (NEFA), albumin, bilirubin, total calcium, total magnesium, creatinine and blood urea nitrogen (BUN) were determined at admission and at dismissal (84 hours). A clinical examination following a standard examination protocol was performed each morning by the same person during the observational period of five calendar days and at dismissal. Ultrasonography was performed in regular intervals of up to 12 hours following admittance. In animals that were referred to the clinic for suspected LDA, ultrasonographic assessment was performed in order to find out whether ...