A note on the flow of endogenous protein to the omasum and abomasum of steers

Three steers cannulated in the rumen and abomasum were given a diet of wheat straw, chopped and soaked in sodium hydroxide and then washed to pH less than 8. The straw was sprayed with sucrose, urea and minerals. The diet was free of digestible protein and given at 1·7 to 4·1 kg/day. Microbial protein flowing to the omasum was measured by 15N. By difference, the flow of endogenous protein nitrogen to the omasum was found to be 2·2 g/kg dry-matter intake. The flow of endogenous protein nitrogen to the abomasum was 3·3 to 9·4 g/kg dry-matter intake, and it decreased with increasing food intake.