Effect of vitamin A restriction in finisher diets of F1 Angus animals with positive DEP for marbling on muscle gene and proteomic expression and the mechanisms involved in muscle fat deposition

Abstract

Given the importance of increasing the degree of marbling of the meat to meet the quality standard for the consumer and add value to the product, there is the possibility of using the restriction of vitamin A in the diet as a tool in the modulation of fat deposition in the carcass of animals. However, the mechanisms involved in the positive interaction between vitamin A restriction and the degree of marbling in the diet of cattle remain poorly defined. The aim of this project is to evaluate the effect of vitamin A restriction in the diet of feedlot cattle on gene expression and muscle proteomics and the mechanisms involved in muscle fat deposition. Forty-two F1 steers (Angus x Nellore), half-brother with positive DEP for marbling will be used, which will be divided into 2 treatments: 1) high content of vitamin A (3170 IU/kg dry matter (DM)); 2) low vitamin A content (1170 IU/kg DM). The diet will consist of 85% concentrate and 15% roughage. The animals will receive the diet in a confinement system, lasting 180 days. Carcass characteristics and meat quality will be evaluated. As well as gene (RNA-seq) and protein (proteomic) expression in muscle tissue. (AU)