Estimates of contributions of VFA [volatile fatty acids] produced in different segments of digestive tract of various species to energy requirements of whole body

Range Table - link % of energy requirements
Organism Mammals
Reference Bergman EN, Energy contributions of volatile fatty acids from the gastrointestinal tract in various species. Physiol Rev. 1990 Apr70(2):567-90. p.575 table 3PubMed ID2181501
Primary Source See refs beneath table
Comments "Table 3 summarizes estimates obtained in various species for the contribution of VFA to the energy requirements of the whole body. Considerable variation is present, and errors undoubtedly have arisen because of methodology or assumptions by the authors. In general, in vitro incubation techniques tend to underestimate VFA production, and in vivo techniques tend to be the most reliable. Also in most cases only the cecum or the large colon was used for calculation. Despite these uncertainties, however, considerable energy must be available from the VFA produced in the lower gut: values from 5 to 30% were obtained, and these are in keeping with the differences in diet and digestive tract morphology. All values were, of course, lower than that obtained from the rumen. The highest figures of 30% were obtained from rabbits and ponies: this is expected, since they are entirely herbivorous and are hindgut fermenters. Pigs and humans seemed roughly comparable, and this also is expected in view of their similarities in digestive tract morphology. The value of 6-10% for humans (Table 3) was calculated on the basis of a typical British diet where 50-60 g of carbohydrate (15 g fiber and 35-50 g sugar and starch) are fermented per day (ref 209 (beneath table))."
Entered by Uri M
ID 111256