Effect of replace sources of nitrogen (soybean meal or urea) by encapsulated nitrate with or without elemental sulfur on ruminal fermentation and enteric methane emission in feedlot cattle

Abstract

Environmental pressures come acting emphatically with respect to livestock production system as a whole, particularly with respect to effect of greenhouse gas emissions from ruminants. Thus, it is necessary the establishment of strategies to optimize the fermentation process, improvements in productivity and maximizing the profitability of production, all these factors will improve the producing of way more efficient. The use of nitrate in cattle diets its a potential strategy, because it is promising replacement of urea as a form of non-protein nitrogen, and, as well, be a partial replacement of true protein source from diet, such as the soybean meal. In the rumen, nitrate is reduced to ammonia, and to this reduction are necessary for reduction of equivalents (H2), thus, this component works as a hydrogen sink in the rumen. The reduced availability of H2 rumen implies in reduction of substrate for methanogenic bacteria, lower production of methane, and lower lost of energy intake by ruminants. Therefore, would possibly better the efficiency of nutrients utilization from diet by cattle. The inclusion of sulfur in the diets with nitrate is also given as a strategy in the H2 usage process, because the sulfur reduction in the rumen consuming H2 and also contribute to microbial synthesis of sulfur amino acids, enhancing microbial efficiency. To accomplish this, we will use the database of intake, digestibility, fecal and urinary excretion of nitrogen, methane emission, efficiency of microbial synthesis, blood methaemoglobin and ruminal parameters evaluations from the dissertation (FAPESP-2016/01562-0). The internship will be developed on the Ohio Agricultural Research and Development Center, located in Wooster, Ohio - United States. The candidate will present the data of dissertation to Professor Chanhee Lee and will have the opportunity to discuss them, in order to improve it them. The trainee will have experience with other methods of analysis and evaluation of results, along with a research group that is led by a researcher with extensive experience in the subject addressed in the project. During the BEPE period the trainee will follow meetings and scientific events with the research group, having the opportunity to present and disseminate their data of your project conducted in Brazil. The period abroad will also allow the student relates with other researchers working in training research center, including reviewers' researchers of international high impact journals. (AU)