Effect Of Volatile Fatty Acids Research Articles

Growth factors for Selenomonas ruminantium.

THE effect of volatile fatty acids as growth factors for rumen bacteria is well known, but in most cases so far reported the branched-chain fatty acids, sometimes in combination with straight chain acids, have been found to be most effective. In a recent paper, Bryant and Robinson1 mentioned that their results showed the importance of acetate in the nutrition of many species of bovine rumen bacteria. However, their strains of S. ruminantium varied in the response to volatile fatty acids, a mixture of such acids other than acetate, propionate and n-butyrate baing stimulatory or essential, while acetate was stimulatory to two strains, but only in the absence of casein hydrolysate. Hobson and Mann2 earlier reported that acetate stimulated the growth of isolates of sheep rumen S. ruminantium and some further observations are described in this communication.

Effect of Volatile Fatty Acids, Sodium and Potassium Bicarbonate in Purified Diets for Ruminants.

Effect of Volatile Fatty Acids, Sodium and Potassium Bicarbonate in Purified Diets for Ruminants.

Studies on the In Vitro Rumen Procedure: Improved Inoculum Preparation and the Effects of Volatile Fatty Acids on Cellulose Digestion

Studies on the In Vitro Rumen Procedure: Improved Inoculum Preparation and the Effects of Volatile Fatty Acids on Cellulose Digestion

Effect of volatile fatty acids, lactic acid and ammonia on rumen pH in sheep

Data are presented on pH, volatile fatty acid, lactic acid, and ammonia nitrogen levels in the rumen of sheep being hand-fed on a wide range of diets. It is concluded that the rumen pH rarely falls outside the range 5.0-7.5 on diets on which lactic acid never accumulates in the rumen after feeding. On such diets rumen pH is closely related to the volatile fatty acid level. Evidence is presented which indicates that the pH-volatile fatty acid relationship on different diets may be considerably modified by variations in salivary secretion and in the accumulation of ammonia nitrogen in the rumen after feeding. The contribution of ammonia nitrogen to the total buffering capacity of the rumen is discussed. Lactic acid only accumulated in the rumen on diets containing high levels of soluble carbohydrate or starch. Lactic acid levels above 20 mM were always associated with pH levels below 3.0, but although levels higher than 80 mM were often recorded, lumen pH levels never fell below 4.33. On these diets rumen pH was closely related to the level of volatile fatty acid or lactic acid or both in the rumen.