Measurements of Purine Derivatives and Creatinine in Spot Urine Samples of Chinese Yellow Cattle

Abstract

An experiment was conducted using 18 Chinese Yellow Cattle located in 5 farms to study how supplementation of fermentable energy to low quality straw-based rations would improve rumen microbial protein synthesis. Within each farm, the animals were fed on five diets. Diets 1–2 were typical rice straw + by-products used by farmers and were low in fermentable energy content; Diets 3–5 were more balanced, containing a higher content of fermentable energy. Purine derivatives (PD) and creatinine in spot urine samples were measured. The results showed that the PD to creatinine ratio was significantly higher with Diets 3–5 than with Diets 1–2. Organic matter digestibility and thus organic matter intake was also higher with Diets 3–5 compared to Diets 1–2. The results indicted that the efficiency of microbial protein synthesis could be improved by balancing the diet.