Volatile Fatty Acids Produced by A Sheep Fed Pure Cellulose as Sole Carbohydrate in its Diet

Abstract

The quantities of volatile fatty acids (VF A) formed from cellulose in the rumen, and their relation to the amount of cellulose digested, have not previously been determined in vivo. We have recently maintained a sheep on a diet of pure cellulose (500 g), gluten (50 g), and inorganic salts (6-20 g) for a period of several months, and have measured VFA production in the rumen along with the extent of digestion of the cellulose in the animal. A characteristic of the digestion was the formation of large proportions (34--42%) of propionic acid, in contrast to the proportions found in the rumen of sheep at pasture, or fed on dry roughages - where propionic acid, though variable, usually constitutes only about 20% of the total VFA. The findings are summarized in Table 1.