Ammonia Anabolism in Ruminants

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Abstract
Ruminal concentration of ammonia [alpha]-ketoglutaric acid glutamic acid glutamine were determined in 2 feeding periods (alfalfa pellet only alfalfa pellet + urea) by using fistulated Corriedal sheep. By the addition of urea the ammonia concentration exhibited significant increases. Glutamic acid decreased in contrast to glutamine in concentration but the differences between the rations were not significant in either case. In the urea ration period [alpha]-ketoglutaric acid decreased but the differences were not significant. By the addition of urea plasma glutamine amino nitrogen increased significantly while plasma ammonia did not increase. Nicotinamide adenine dinucleotide (NAD)-linked glutamic acid dehydrogenase (GAD) activity was demonstrated not only in the rumen mucosa but also in the mucosa of reticu-lum omasum. The NAD-linked GAD activity was also demonstrated both in the rumen protozoa bacteria. Glutamine was hydrolyzed by the rumen mucosal homogenate to liberate ammonia. The cell free preparation of the rumen protozoa rich fraction or bacteria also produced ammonia from glutamine. At a high rumen ammonia concentration ammonia was incorporated into glutamic acid by reduction of [alpha] -ketoglutaric acid furthermore a part of the glutamic acid entered into the circulation through the rumen wall after it was converted to glutamine. These synthetic reactions should be carried out in the stomach mucosa the rumen microorganisms.