Influence of urease inhibitors on urea hydrolysis in ruminants

The data from the 1965 Livestock Feeders’ Day Bulletin indicate that ammonia production from animals fed urea rations was higher than that from nonurea rations. For the bacteria to “capture” more ammonia from urea rations and utilize it, several experiments were designed to test the effect of a variety of chemicals that theoretically would inhibit urea hydrolysis per se. These were initially screened by an artificial rumen technique. The chemicals exhibiting inhibition were then tested inside fistulated steers to stimulate practical feeding conditions. At the same time several products were fed to sheep for digestibility data. A preliminary report of the data follows.