Ruminal fluid metabolomics associated with diet and environmental impact of Nellore cattle

Abstract

The prodution of beef cattle in Brazil has allowed the country to occupy a prominent position in the world meat trade, and enabled a growth in number of feedlot animals in the national territory. Despite this knowledge, the cost of feed represents the largest monetary investment at a feedlot. Thus, agro-industrial by-products, along with feed efficiency, greenhouse gas emissions and water footprint can be an effective alternatives for the nutrition and selection of beef cattle. In this context, the present project proposes to study the metabolites of ruminal fluid and feces from beef cattle that have received different diets, in order to understand how feed influence the rumen metabolism and the phenotypic characteristics related to environmental impact. Therefore, the ruminal fluid and feces samples from 50 Nellore cattle (Bos indicus), uncastrated male, submitted to different nutritional interventions (conventional and by-product based) will be collected. Different extraction methods will be used for polar and non-polar metabolites, in order to standardize processing methodology for both Nuclear Magnetic Resonance Spectroscopy (1H NMR) and Gas Chromatography coupled to Mass Spectrometry (CG-MS). The data obtained will be analyzed by means of uni and multivariate statistics for the identification of differentially expressed metabolites. Next, the potential metabolic pathways will be evaluated to understand the mechanisms involved in the emission of methane and water footprint size, as well as its relation with the composition of the microbiota. Thus, the present project will use new technologies in the identification of biomarkers, which may prove useful in animal breeding experiments in beef cattle to contribute to the national agribusiness, the agro-industry and scientific knowledge.