Increase in branched-chain amino acids due to acidemia in neonatal calves with diarrhoea.

The aim of this study was to investigate the relationships between acid-base status and plasma branched-chain amino acids (BCAA) concentration in calves with diarrhoea for intravenous nutrition, especially with amino acid solution in calves with diarrhoea. Thirty-four Holstein calves aged 11.0±5.9 days old were enrolled in this study. In 10 of 34 calves exhibiting clinical signs of diarrhoea, severe dehydration and acidemia were observed (severe group: pH: 7.04±0.11, base excess (BE): -17.4±4.5) based on blood gas analysis. In 7 of 34 calves exhibiting clinical signs of diarrhoea, mild dehydration and acidemia were observed (mild group: pH: 7.29±0.06, BE: 0.0±5.2). The other 17 calves did not exhibit dehydration or acidemia (pH: 7.41±0.02, BE: 11.2±3.5) based on clinical signs and blood gas analysis. The plasma concentration of BCAA was significantly higher in the severe group than in the other groups. In addition, the blood pH and plasma concentrations of BCAA (r=-0.41, P<0.05) were significantly and negatively correlated. As calves with metabolic acidosis have increased plasma BCAA concentrations due to hypermetabolic states of proteolysis, amino acid solutions containing low concentrations of BCAA may be useful to gradually correct the negative nitrogen balance.