Fatty acid profiles abundances characterization in skeletal intramuscular fat related to dietary changes in early-weaned Nellore calves.

• Grant number: 24/15821-4
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: December 01, 2024
• End date: March 31, 2025
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Genetics and Improvement of Domestic Animals
• Principal Investigator: Guilherme Luis Pereira
• Grantee: Rebeca Soares Nogueira
• Supervisor: Christina Ramires Ferreira
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Institution abroad: Purdue University, United States
• Associated to the scholarship: 24/06960-0 - Identification of genes relates to diferences in fatty acid profiles in skeletal muscle between Nelore cattle weaned in a convencional and early way in the north of the Pantanal., BP.IC

Abstract

Due to the importance of the Nelore breed in Brazilian beef cattle farming, research involving genetic modification and improvement in meat quality has been increasingly developed in the country. Early weaning has been shown, among other nutritional management, to be a genetic selection technique, considering that it allows a reduction in the period between births. In addition, early weaning and supplementation with concentrated diets during the breeding phase, an extremely important phase in the animal's development, can lead to considerable changes in metabolism, which are intrinsically connected to the parameters determining meat quality such as lipid concentration and composition. Techniques such as Lipid exploratory analysis are commonly performed using liquid chromatography. However, these methods give limited lipid structural information, typically only information on the general lipid class or fatty acyl residues. Advances in instrumentation and ionization methodologies in mass spectrometry (MS) allow FAs and glycerophospholipids to be detected as intact ionized molecules. MS can therefore be used to study the lipid composition of a broad range of samples of the complex composition containing limited amounts of lipids. The MRM method that uses the MS/MS approach (not LC-MS/MS), developed by Purdue University researchers is a simplified method of lipidomics that doesn't need the use of chromatography, the step used to separate molecules in the common form of lipidomics. The profiling through lipidomics has been explored in animal production and meat quality to elucidate the direct effects of diet in the muscular lipid profile and indirectly of meat quality traits, such as color and softness of the meat. In this context, the objective is to use MRM technique to search for fatty acids differentially abundant among muscle samples from early and conventionally weaned Nellore young bulls. For this, muscular biopsies samples from 40 young bulls (915d) were collected 24h before slaughter, of which 20 early weaned (120 days) and 20 conventional weaned (205 days), respectively. The lipids samples will be extracted from each meat sample using Bligh and Dyer method, and will be submitted to the MRM method. The total of MRMs entries will be normalized considering ion intensities and the relative intensity data using auto scaling and transforming procedures to normality. Statistical analysis will be performed using the PLS-DA approach to select the most important lipid on discrimination groups (EW and CW). After, lipid ontology enrichment of target discriminant lipids profiles will be conducted using LION webtool. In this way, it will be possible to identify different lipid and fatty acid profiles that were differentially abundant among treatments, which could in part be the result of metabolic modulation caused by changes in environment and diet during the cow-calf phase. This experiment will bring unprecedented results in this study topic for the Nelore cattle breed. Ultimately, the student will gain expertise in advanced metabolite analysis techniques utilizing mass spectrometry and will acquire skills in the application of statistical tools and functional databases for lipidome research.