The application of 13C-labelled short chain fatty acids to measure acetate and propionate production rates in the large intestines. Studies in a pig model.

Abstract

The production rates of acetate and propionate were measured in the large intestine of pigs by applying the single injection technique of (1-13C)acetate and (1-13C)propionate. Both acids were injected individually through the caecal cannula and for both acids the experiments were performed during two diets with different crude fibre contents. For acetate the increase of dietary crude fibre from 5.1 to 18.3% of dry matter resulted in an increase of mean production rate from 27.4 to 56.2 mmol/h. The mean propionate production rate was raised from 3.6 to 7.0 mmol/h when the dietary crude fibre was increased from 4.4 to 24.3%. From both experimental series the contribution of hindgut fermentation to energy maintenance requirement were estimated to be in a range between 7 and 40% depending on the body weight of the animals and the percentage of dietary crude fibre.