THE PRODUCTION OF ORGANIC ACIDS IN THE PIG: I. THE EFFECT OF DIET ON THE PROPORTIONS OF VOLATILE FATTY ACIDS IN PIG FECES

Experiments were conducted to determine the effect of diet, level of feeding and age and/or weight on the proportions of volatile fatty acids (VFA) in the feces of pigs. Cellulose was added to the control ration fed in one experiment and dried whey or bran to that fed in another experiment. When the level of intake of the cellulose-supplemented ration was reduced, the digestibility of crude fiber in the ration increased. The proportion of fecal acetic acid also increased, but the difference observed did not reach statistical significance at P = 0.05. Differences in the proportion of acetic, butyric and valeric acid due to cellulose supplementation of the control ration were statistically significant (P < 0.05). The whey and the bran-supplemented rations gave statistically significant differences (P < 0.05 or P < 0.01) for the proportions of fecal valeric, propionic or acetic acid. The proportions of fecal VFA appeared to be relatively unaffected by the age and/or weight of pigs from weaning to market weight.