Absorption of Volatile Fatty Acids, Tritiated Water and Antipyrine From the Abomasum of Goats

Abstract

In conscious goats the abomasum was isolated temporarily from the rest of the gastro-intestinal tract by means of balloons, or a double by-pass or a snare around the pylorus. Abomasal contents, rumen fluid or a saline solution were given into the abomasum. Altogether forty experiments were done on four goats.The absorption of acetic acid, propionic acid, butyric acid, tritiated water (HTO) and antipyrine (AP) from the abomasum was measured. For comparison of the absorption rates, the data were given as clearance of the abomasal fluid and as water (liffusion.At a mean abomasal fluid volume of 606 ± 201 ml., 513 ± 169 ml. water diffused out of the abomasum through the abomasal mucosa per hour. The antipyrine clearance was 214 ± 84 ml./hr. The volatile fatty acids (VFA) were absorbed considerably faster at acid than at neutral pH values; at pH 5-2 -5-6 the VFA clearance was only 320 ml./hr.: at pH 3-5-4-0, however, it increased to 1130 ml./hr.The olive oil: water partition coefficients for acetic, propionic and butyric acid were measured in the pH range of 3-5 -6-2. With decreasing pH values the degree of dissociation of the acids decreases and the lipid solubility increases considerably.The permeability of the abomasal and ruminal mucosa for VFA also increases at lower pH values, but not as much as the olive oil: water partition coefficients of the acids.Absorption of VFA, HTO and AP from the abomasum is discussed in relation to the absorption of these substances from the rumen and the human stomach.

Effect of exogenous butyrate on the gastrointestinal tract of sheep. I. Structure and function of the rumen, omasum, and abomasum1

“…Greater epithelium thickness in the pyloric region of the abomasum of BUT animals is in line with the previously reported trophic effect of butyrate on the stomach tissue mass in monogastric animals (Kotunia et al, 2004;Mazzoni et al, 2008). It was also shown that butyrate is absorbed from the abomasum (Engelhardt et al, 1968;Williams et al, 1968). When absorbed, butyrate is most likely completely oxidized by the abomasal epithelium (Guilloteau et al, 2009;Guilloteau et al, 2010a).…”

Digestion, Absorption and Transport of Lipids in Ruminant Animals

“…16 ' 32,47 Nonetheless, the abomasum has the capacity to absorb short-chain fatty acids and Ash 15 and subsequent investigators have shown that, of the short-chain fatty acids which reach the abomasum, a high proportion is absorbed there. 72,151,301 Furthermore, many of the absorptive characteristics of the system operating within the rumen, e.g. The latter workers also demonstrated that, despite the low concentrations of short-chain fatty acids that were found in the abomasum, the absorption occurring there was quanti tatively significant and could supply up to 10% of the basal metabolic requirements of the animal.…”

“…Badawy et al, 11 using insoluble ash as an inert marker, estimated that in the sheep, 74% of the shortchain fatty acids present in the abomasal contents were absorbed, while Engelhardt et al, 12 using the surgically isolated abomasum of the goat, gave a figure of 90%. 72 Indeed, it was suggested by these authors that the low concentrations of the short-chain fatty acids in the abomasal contents were due more to the rapid absorption occurring there than to prior absorption from the omasum.…”

Disappearance and passage of propionic acid from the rumen of the beef steer.

“…Ruminally produced propionic acid must be absorbed across the epithelium in order to enter the animal. Previous reports indicate that 76 to 95% of ruminally produced propionic acid is absorbed in the rumen; however, those studies were conducted with sheep (Gray, 1947;Weston and Hogan, 1968;Williams et al, 1968) or in animals whose normal rumen conditions were not maintained (Masson and Phillipson, 1951;von Engelhardt et al, 1968). The capacity of the rumen to remove propionate at elevated levels of production characteristic of today's high producing ruminants remains unknown.…”