Understanding beef cattle metabolism: i) metabolomics approach and biological meaning; ii) calves metabolism and health through nutritional strategies

• Grant number: 25/02956-1
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: July 01, 2025
• End date: December 31, 2025
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Production
• Principal Investigator: Nara Regina Brandão Cônsolo
• Grantee: Lauro César Ferreira Beltrão
• Supervisor: Vinicius Silva Machado
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Texas Tech University (TTU), United States
• Associated to the scholarship: 24/08812-9 - Correlation between serum metabolites and growth characteristics, musculature, and precocity in Nellore cattle., BP.MS

Abstract

Weight gain is the most important economic variable in beef farms, serving as a key indicator that the production system is being managed correctly and will be profitable for the producer. Beef cattle farming in Brazil is one of the most prominent agricultural activities and plays a crucial role in the national economy. Zebu breeds (Bos indicus), originating from India, possess the necessary traits to adapt to the production systems employed in Brazil. Due to their remarkable ability to thrive and produce in tropical conditions, Zebu cattle account for more than 80% of the national herd. A fundamental step in meeting the growing global demand for beef is the development of specific management strategies for Bos indicus cattle in tropical and subtropical environments. Animal selection for growth can alter metabolic rates and metabolite concentrations, influencing traits such as body maturity, muscle fiber type and/or morphology, and carcass fat deposition. Metabolomics emerges as a powerful technique that enables the identification and quantification of thousands of low-molecular-weight metabolites, which serve as intermediates or final products of metabolism. This study aims to correlate serum metabolites with growth, muscularity, and precocity traits in Nellore cattle. A total of 95 post-weaning Nellore calves will be used, maintained in paddocks with Urochloa brizantha pasture and supplemented with a protein-energy supplement at 0.5% of their body weight. The animals will be weighed monthly for diet adjustment, and these weights will be used to generate the growth curve. Additionally, carcass ultrasound evaluations will be performed every two months using an Aloka SSD500 device equipped with a 3.5 MHz, 178 mm linear transducer coupled with an acoustic guide. The ultrasound analysis will assess the Longissimus muscle area, the subcutaneous fat thickness over the Longissimus muscle between the 12th and 13th ribs, the subcutaneous fat thickness over the Biceps femoris muscle, and rump depth. After the growing phase, these animals will proceed to the finishing phase, where the diet will be formulated based on a roughage-to-concentrate ratio of 70:30. Every 28 days and on the day before slaughter, body weight (BW), average daily gain (ADG), and feed efficiency (FE) will be evaluated. Carcass ultrasound will also be performed on the same days as the weigh-ins to assess the growth curve of muscle and adipose tissues. Additionally, blood samples will be collected during the pre-slaughter handling for serum metabolomic analysis. The serum metabolomic profile will be determined using an NMR spectrometer (Bruker Corporation, Ettlingen, Germany) at Embrapa Instrumentation, located in São Carlos, SP, Brazil. After obtaining the spectra, metabolites will be quantified using the Chenomix NMR Suite Professional 10.1v software (Chenomx Inc., Edmonton, Canada). The resulting data will be exported to an Excel spreadsheet for subsequent analysis.