A technique for the collection of reticular effluent of sheep

Two sheep were equipped with rumen and omasal fistulae. A teflon tube with 1 mm outer diameter (OD) was permanently fixed between the abomasal fistula and the reticulo-omasal orifice. The effluent sampling tube was introduced through the abomasal cannula, through the omasal canal into the reticulo-omasal orifice by aid of the teflon tube. The technique allowed direct collection of reticular effluent from sheep. Intermittent flow of reticular effluent was observed. The moments of flow coincided with the end of the second phase of reticular contractions. From the flow pattern it was concluded that the motility of the reticulo-omasal orifice was not affected by the sampling procedure. From the similarities in the pH values, DM contents, and total protozoal counts in the effluent and in the reticular samples, it was concluded that representative samples of effluent could be obtained by the method. One animal was used for sampling for a period of eight months and then again 2 1/2 years later. A fraction of 97 to 98% of the DM present in the reticular effluent and in the reticular samples passed a sieve with 1 mm pore size. From the analyses of reticular content and reticular effluent it was concluded that the reticulo-omasal orifice does not have a significant discriminating function for the selective passage of particles and protozoa into the omasum.