Absorption of steam volatile fatty acids from the reticulo-rumen of anaesthetised calves

Abstract

Abstract Absorption of volatile fatty acids (VFA) from the rumen of calves 3 to 5 days old was investigated to determine if the ability to assimilate the acids is inherent in the rumen epithelium. The effects of advancing age and diet on VFA transport were examined in calves 6 weeks old fed either solely on milk or on milk and pasture. Absorption was measured by changes in the veno–arterial VFA concentration difference of the rumen after the introduction of test solutions into the fasted, emptied, and rinsed forestomach of anaesthetised animals. Significant increases in the veno–arterial VFA concentration difference of the rumen (P <0.01) were noted in the three groups of calves after the introduction of the acids into the rumen. These increases were similar in the three groups of animals. No differences in VFA assimilation rates were detected between the two groups of older calves. Endogenous sources of circulating VFA and rapid removal of assimilated acids from the peripheral circulation were indicated.