Integration of Ruminal Volatile Fatty Acid Production Methods, Ruminal Fluid Sampling Techniques, and Mathematical Modeling

98 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1999.A series of technical studies were performed to develop simpler methods of measuring the rate of ruminal volatile fatty acid (VFA) production and a practical but effective way of sampling ruminal fluid. In experiment 1, an in vitro technique (procedure and mathematical approach) were developed to estimate ruminal VFA production in vivo. This method provides a practical approach to measure the ruminal fermentation of different diets and their impact on the profile of nutrients available for production under non-steady state conditions. In experiment 2, a device was developed which allowed time-integrated samples of ruminal fluid to be collected without repeated entry into the rumen. This method simplified the collection of ruminal fluid and produced samples representative of overall ruminal fermentation, providing a promising alternative to conventional sampling techniques. This method may prove useful in investigating factors affecting the dynamics of ruminal fermentation and may also help in the identification of variables associated with various metabolic diseases. In experiment 3, a technique for measuring the rate of ruminal VFA production (under steady state conditions) in large ruminants using a stable isotope was developed. This allowed the rate of ruminal VFA production to be measured without the health and safety concerns associated with radioactive isotopic studies. This method provides a promising alternative to conventional radioactive isotope dilution techniques and may prove useful in studying the factors affecting ruminal fermentation.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD