Differential protein expression of Longissimus thoracis skeletal muscle of Nellore cattle submitted to early weaning

• Grant number: 23/00511-7
• Support Opportunities: Scholarships abroad - Research
• Start date: June 05, 2023
• End date: September 09, 2023
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Genetics and Improvement of Domestic Animals
• Principal Investigator: Guilherme Luis Pereira
• Grantee: Guilherme Luis Pereira
• Host Investigator: Andre Martinho de Almeida
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Institution abroad: Universidade de Lisboa, Portugal

Abstract

The Nellore breed is of great importance in national beef cattle agroindustry since it is extremely adapted to the prevailing tropical climate conditions. Compared to taurine breeds, in general, Nellore cattle have low production rates, such as low feeding and reproductive efficiency, and lower quality meat. The quest to increase technical and economic efficiency in meat production in Brazil has led to the adoption of some strategies to improve efficiency. Among these, early weaning is an important management strategy that consists of weaning calves from 60 years of age and has helped to improve the reproductive efficiency of females. In addition, this type of management has a great impact on metabolism, especially muscle and lipid, of calves weaned early, which can lead to an improvement in the quality of the carcass and meat. However, information on the effect of this strategy in Zebu cattle is inconsistent. In this sense, with the aim of studying the effect of early weaning on the performance and quality of beef, 40 Nelore calves will be used, where 20 will be weaned early (at 120 days) and 20 conventionally (at 205 days ). For this, muscle tissue samples will be collected through biopsy at two different times: at 205 days of age of the calves, and immediately after slaughter at 740 days of age. At this last moment, samples will also be obtained for analysis of meat quality in the meat laboratory of FMVZ-Unesp, Botucatu-SP, through the evaluation of shear force, intramuscular fat content, meat color (L*, a* , b*, Chroma and hue), water retention capacity (loss of water due to thawing, cooking, pressure), lipid oxidation and sensory analysis of the meat. After that, samples of Longissimus thoracis skeletal muscle collected by biopsy will be sent to the Instituto Superior de Agronomia da Universidade de Lisboa, Lisbon-PT, where the proteome analysis will be performed for the two collection moments and for the two groups based on label free proteomic shotgun approach via nano-LC-MS/MS. Finally, using multivariate statistics, data from the proteome and meat quality parameters previously obtained will be analyzed in an integrated way, aiming to improve the understanding of marbling deposition mechanisms and, also, the prospect of possible biomarkers for this traits. (AU)