Lipidomics of bovine skeletal muscle as biomarkers for meat quality and feed efficiency

Abstract

As Brazilian beef exports grow, the conquest of new markets is becoming more dependent on the quality of the meat of these animals. The intramuscular lipid deposition in cattle determines the superior quality of the product, mainly due to the influence on the flavor and juiciness of the meat. Negative correlations between the amount of fat deposition and the efficiency of feed usage are also described. In a recent integrative analysis of the expression of miRNA-mRNA (Thematic project Fapesp 12/23638-8) in a population of Nellore animals, the group observed bta-let-7f and bta-let-7a-5p as expressed miRNAs in association with different degrees of intramuscular fat deposition; which indicates the possible involvement of miRNAs in the development of adipose tissue. Thus, this study aims to evaluate the profile of lipids in the skeletal muscle of beef cattle that received different diets (conventional and by-products) to understand how food affects lipid metabolism and which are the underlying effects on the functional genome. For this purpose, samples of skeletal muscle from 52 Nellore animals (Bos indicus) will be used, submitted to different nutritional interventions (conventional and by-product). Different lipid extraction methods will be used to standardize the technique to assess the metabolism of these compounds as a meat quality standard by mass spectrometry coupled with liquid or gas chromatography. For data validation, cell culture of muscle and/or adipose cells will be performed, with Western blot and qPCR, with specific markers correlated with the lipidome findings. The data obtained will be analyzed using univariate and multivariate statistics to identify differentially expressed lipids. Subsequently, pathways related to the correlation of lipids with the production profiles of the animal and its microbiome will be evaluated. Thus, in this proposal, we hope to obtain and validate the lipid profile in the muscle tissue of Nellore cattle, contributing with information for the construction of the lipidome of these animals and relating these information to animal production, strengthening the Brazilian agriculture, in addition to the need to reduce production costs and environmental impacts. (AU)