Study of enteric methane production under the perspective of new variables of rumen fermentation

• Grant number: 11/11165-5
• Support Opportunities: Regular Research Grants
• Duration: November 01, 2011 - October 31, 2013
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: Paulo Henrique Mazza Rodrigues
• Grantee: Paulo Henrique Mazza Rodrigues
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated researchers: Alexandre Berndt ; João José Assumpção de Abreu Demarchi ; Rosa Toyoko Shiraishi Frighetto

Abstract

In times of concerning regarding to global warming by greenhouse gases (GHG), the stratification of responsibilities of each economic sector in relation to emission of GHG is urgent. As a natural source of methane emission, livestock, specially cattle, is part of this accountability. Aiming at quantifying daily litres of methane emitted by ruminants, Animal Scientists worldwide pursuit the development of techniques that can be used to this end. National inventories of methane emissions are published periodically based on these tecniques. However, the mere quantification of daily methane emission by cattle does not provide a comprehensive approach about effciciency of ruminal fermentation. In this way, it is desirable quantifying not only methane production by unity of time but also short chain fatty acids (SCFA) acetic, propionic and butyric, the main products of ruminal fermentation. Therefore, the relationship between production of SCFA and methane on a determined period of time may bring new information about understanding the process of ruminal fermentation as well as its efficiency. Hence, the goal of this project is to develop a methodology for quantifying methane production from bovine ruminal fermentation in relation to SCFA and to evaluate this rate on different conditions. Quantification of total gas production per millilitre of rumen fluid kept in glass bottles over a certain period of time will be carried out. Time of fermentation will be controlled by ceasing fermentation through a rapid drop in medium pH. Total gas production will be measured by pressure meter system whereas concentration of methane and SCFA by gas chromatography. Thus, we propose four experiments: effect of type of energetic source, effect of mitigating feed additives, effect of time and type of diet as well as effect of genetic group on ruminal methanogenesis. (AU)