Volatile fatty acids in adult and young ruminants: an evaluation of a gas chromatographic method.

A gas chromatographic method was evaluated for the quantification of volatile fatty acids in blood plasma from ruminants. Amounts of .002 mg acetic acid and .001 mg of propionic and butyric acid could be quantified. Diurnal variation in acetate and propionate was found when blood samples were taken during 1 d from five cows. Jugular blood samples were taken from the five cows 8 wk before parturition to 10 wk after parturition and from three of their calves to 32 wk of age. Acetate decreased in cows at the weeks around parturition. Calves had very low acetate during the first 10 wk of life, but the concentration subsequently increased to that in adult ruminants. Propionate concentration was below .17 mM and butyrate concentration below .08 mM in all samples. It was concluded that this method was suitable for analyzing volatile fatty acids in blood plasma from ruminants, which is of importance in the study of metabolic diseases.