Development of a methodology for quantifying methane production from ruminal fermentation of bovine

• Grant number: 10/15670-3
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date until: March 01, 2011
• End date until: February 28, 2014
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: Paulo Henrique Mazza Rodrigues
• Grantee: Lerner Arévalo Pinedo
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Techniques for measuring methane emissions by ruminants have already been described, but aiming at quantifying total emission from animals. This variable is appropriate for inventories in which data of total production of methane by ruminants in a given country are published. Nevertheless, the simple quantification of methane may not provide a comprehensive approach to efficiency of ruminal fermentation. From a nutritional point of view, it is desirable to quantify not only the production of gas per unit of time but also short-chain fatty acids (SCFA) acetic, propionic and butyric acids, the main end products of ruminal fermentation. The study of the relationship between these two variables may bring new information about understanding the process of rumen fermentation as well as its efficiency. Hence, the goal of this project is to develop a technique for quantifying methane production from ruminal fermentation of bovine in relation to SCFA and to evaluate it under different conditions. The technique consists in quantifying all the methane produced per millilitre of rumen fluid kept in glass bottles over a certain period of time. Time of fermentation will be controlled by ceasing fermentation through changes in medium pH. Total gas production will be measured by means of a bubble flow meter whereas methane and SCFA concentration by gas chromatography. Three experiments will be carried out with the purpose of developing the technique: 1) Effect of time of incubation of rumen fluid and type of diet, 2) Effect of the preparation of the bottle and 3) Effect of the substrate on methane production.Key words: Metodology, methane, ruminal fermentation, ruminants. Another three additional experiments will be performed to employ the new developed technique aiming at verifying: 4) Effect of genetic group and type of diet, 5) Effect of energy source and 6) Effect of feed additives on methane production.Keywords: Rumen fermentation, methane, short chain fatty acids, ruminants. (AU)