Estimation of Microbial Protein Supply in Ruminants Using Urinary Purine Derivatives

The Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture has a long history of coordinating isotope aided research projects for improving animal productivity in developing countries. These projects have focused on enhancing the efficiency of animal production through better use of locally available feed resources and those that do not compete with human food. As a part of these efforts, the Joint Division has been actively involved in developing and simplifying approaches for measuring microbial protein supply to ruminant livestock. The contribution of microbial protein in meeting the overall requirement for protein in ruminants is significant, but understanding the contribution of microbial protein to the nutrition of ruminant livestock has been hampered by the lack of simple and accurate methods for measuring microbial protein production in vivo. A Consultants' Meeting was held in 1995 in Vienna to explore the feasibility of using nuclear and related techniques to develop and validate new approaches for measuring microbial protein supply in ruminant animals. Based on the available information, the consultants considered that the purine derivative excretion method, which is non-invasive and both simple to use and inexpensive compared with other available methods, had the potential for use in developing countries. However, development of models for various animal species and breeds and their validation were required before this technique could be advocated for use.

Contenu
Development, Standardization and Validation of Nuclear Based Technologies for Estimating Microbial Protein Supply in Ruminant Livestock for Improving Productivity.- The Use of Urinary Excretion of Purine Metabolites as an Index of Microbial Protein Supply In Ruminants.- Some Aspects of Recovery of [14C]-Allantoin in the Urine of Sheep.- Effect of Physiological Status on Endogenous Excretion of Purine Derivatives in Cattle.- An Overview on the Use of Urinary Purine Derivatives Excretion as a Method for Estimation of Rumen Microbial Protein Production in Swamp Buffaloes and Zebu Cattle.- Purine Derivative Excretion and Recovery of 14C-Uric Acid in Urine of Ongole Cattle Given Different Levels of Feed Intake.- Glomerular Filtration Rate and Renal Recovery of [14C]-Allantoin in Bali and Zebu Cattle of Indonesia.- Flow of Nucleic Acids from the Rumen and Recovery of Purine Derivatives in the Urine of Cattle and Buffaloes.- Comparison of Purine Derivatives and Creatinine in Plasma and Urine Between Local Cattle and Buffaloes in Vietnam.- Evaluation of the Use of Purine Derivatives:Creatinine Ratio in Spot Urine Samples as an Index of Microbial Protein Supply in Yerli Kara Crossbred Cattle.- Urinary Excretion of Purine Derivatives as an Indicator of Microbial Protein Supply in Sri Lankan Local Zebu Cattle and Crossbred Milking Cows.- The Effect of Different Levels of Feed Intake on the Urinary Excretion of Purine Derivatives in Chinese Yellow Cattle.- Measurements of Purine Derivatives and Creatinine in Spot Urine Samples of Chinese Yellow Cattle.- Estimation of Microbial Protein Supply of Lactating Dairy Cows under Smallholder Farms in North-East Thailand Using Urinary Purine Derivative Technique.- Purine Derivatives/Creatinine Ratio as an Index of Microbial Protein Synthesisin Lactating Holstein Cows.- Urinary Excretion of Purine Derivatives and Its Utilization as an Index of Microbial Protein Synthesis in the Fore-Stomach of the Camel.- The Effect of Plane of Nutrition on the Urinary Purine Derivative Excretion in Sheep and Goats.- Measurement of Purine Derivatives and Creatinine in Urine by Hplc.- Prediction of Purine Derivatives, Creatinine and Total Nitrogen Concentrations in Urine by Ft-Near-Infrared Reflectance Spectroscopy (Ft-Nir).- Measurement and Application of Purine Derivatives:Creatinine Ratio in Spot Urine Samples of Ruminants.- Research on Urinary Excretion of Purine Derivatives in Ruminants: Past, Present and Future.- List of Participants.