Etiology of acetonemia in Norwegian cattle. 2. Effect of butyric acid, valeric acid, and putrescine.

A feeding experiment was performed on 16 cows in order to test the effect of naturally occurring substances in silage on forage intake, ketonemia, and milk yield. The cows were divided into a control group and three experimental groups. The cows in the three experimental groups were fed 100 g/d of putrescine, 200 g/d of valeric acid, or 200 g/d of butyric acid through a ruminal tube for 3 d. Butyric acid increased plasma acetoacetate; the effect was largest in high yielding cows. Putrescine influenced both milk yield and forage intake and may possibly be a contributory factor, alone or combined with other amines, for the development of ketonemia. Valeric acid did not influence feed intake or plasma acetoacetate concentration. A rapid method for acetoacetate analysis also is described.