Investigation of the metabolic differences in Nelore steers with varying rates of fat deposition during the rearing phase.

• Grant number: 24/14956-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2024
• End date: September 30, 2025
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Production
• Principal Investigator: Nara Regina Brandão Cônsolo
• Grantee: Giovana Rego Barros Massa
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 20/08845-3 - The metabolomic approach to improve Nellore beef tenderness: a concept of metabotype and biomarkers, AP.JP

Abstract

Beef cattle farming in Brazil is a crucial activity for the country's economy, standing out with the largest commercial herd in the world, mainly consisting of zebu breeds like Nelore. Although this breed is adapted to tropical climates, it has lower growth rates compared to taurine breeds, and its meat presents greater challenges in terms of quality, especially regarding tenderness. With the increasing demand for higher quality meat, it is essential to refine the selection of economically important traits, particularly concerning fat deposition and muscle growth during the rearing phase. In addition, metabolomics, an omics science that is constantly evolving, integrated with techniques such as carcass ultrasound, offers an innovative perspective to better understand the metabolism of these animals, leading to improvements in meat production and quality. Thus, this proposal aims to evaluate the metabolism of Nelore steers during the rearing phase, focusing on the precocity of fat deposition in the carcass by identifying and quantifying metabolites in the serum of steers with different rates of fat deposition in the Longissimus thoracis and Biceps femoris muscles, as well as assessing the metabolomic pathways correlated to these variables. For this purpose, during the rearing phase, 100 Nelore steers will be evaluated, receiving a daily protein/energy concentrate supplementation of 0.3% of body weight (BW) and being monitored by carcass ultrasound every 60 days. Additionally, weight gain will be monitored with weighings every 28 days until they reach approximately 370 kg, at which point they will be divided into groups based on fat deposition. Blood samples will be collected for metabolomic analysis by nuclear magnetic resonance (NMR), and spectral images will be processed using the Chenomx NMR Suite 7.5 software. Metabolites will be identified using the Profiler and Library Manager in the same software, which contains 304 different metabolites, and the concentration data of each metabolite in each sample will be exported from the Chenomx software into an "xlsx" spreadsheet, where they will be analyzed using univariate and multivariate strategies executed on the MetaboAnalyst 6.0 platform to identify the relationship between metabolomics and metabolomic pathways correlated with the precocity in subcutaneous adipose tissue deposition in beef cattle during the rearing phase.