Relationships between acid-base balance, serum composition and colostrum absorption in newborn calves

Twenty-seven newborn Holstein bull calves were bottle-fed 2 litres of pooled colostrum which had been stored at −20 °C. Blood gas analysis before feeding showed a partially compensated respiratory acidosis in most of the calves, although they all appeared to be clinically normal. Mean venous blood pH was 7·346, carbon dioxide tension ( Pco 2) was 57·5 mmHg (7·6 kPa), bicarbonate was 30·6 mmol/l and base excess was 3·82 mmol/l. Mean serum IgG 1 increased to 8·1 g/l after feeding colostrum. Several significant positive correlations were observed between post-absorptive serum protein, IgG 1, IgM, γ-glutamyltransferase (γGT) and d-xylose. Calves with either low serum albumin, high serum CK or low serum γGT before feeding tended to have less absorption of colostral protein. It was concluded that reduced absorption of IgG 1 from colostrum is associated with hypercapnia in apparently healthy newborn calves.