Controlled studies of various treatments for neonatal calf diarrhoea in calves of known immunoglobulin levels.

The effects of whole blood transfusion (trial 1), balanced fluid replacement therapy (trial 2) and fluids plus antibiotics (trial 3) on spontaneously occurring neonatal calf diarrhoea were studied under controlled experimental situations using calves of known immunological status as determined by their zinc sulphate turbidity (ZST) levels. Market Ayrshire or Ayrshire cross Friesian calves were chosen with ZST values between 5 and 15 units. Significant differences were not found in survival, weight gains or days of diarrhoea between treatment and control groups in any of the three trials. In the control groups of trials 2 and 3 ZST units were significantly higher in survivors than in those calves that died. The experimental design used provided a controlled and practical method of testing various treatment programmes with calves of known immunoglobulin levels. The different therapies and the importance of defining the immune status of experimental animals are discussed.