Protein Metabolism in Swamp Buffalo

Abstract

The food for ruminants; forages and fibrous roughages, consist mainly of |3-linked polysaccharides such as cellulose, which cannot be broken down by mammalian digestive enzymes. Ruminant have therefore evolved a special system of digestion that involves microbial fermentation of food prior to its exposure to their own digestive enzymes. The rumen microbes can use simple compounds such as ammonia and to make their cells which in turn provide the animal with most of its protein need. The purines from the rumen microbes are metabolised and excreted in the urine as their end products: hypoxanthine, xanthine, uric acid and allantoin. That is why the research work has been carried out actively for the past 20-30 years into the urinary excretion of these purine metabolites, with an objective to use the excretion of these metabolites as a parameter to quantitatively estimate the supply of rumen microbial protein to the ruminant. Recently several studies in the field have concluded that buffaloes have much lower (and more variable) urinary excretion of purine derivatives (PD) per unit DOMI than cattle (Chen and 0rskov, 2004), but the mechanisms were not fully understood.