An omaso-abomasal cannula used to assess efflux from the omasum of sheep.

An omaso-abomasal cannulation technique was developed for sheep to assess efflux from the omasum. The procedure enabled the collection of the total omasal effluent and avoided transection of the innervation and circulation of this region of the gut. Eating was associated with an increase in flow of the fluid and dry matter fractions of digesta passing from the omasum but efflux was unaffected by rumination. There were few protozoa and flagellated organisms in the omasal effluent relative to the numbers in ruminal fluid. The preparation was used over 3 months of study.