Evaluation of growth and beef quality traits in lineages and representative Nelore sires, using ultrasound, video image and NIRS measurements.

Abstract

The objective of this study is to evaluate the differences of growth, carcass composition and beef quality traits among lineages and representative Nellore sires, using new technologies to collect data and estimate of genetic and phenotypic parameters. Data on growth, carcass and meat quality traits of 2.500 Nellore steers and bulls, grown in pastures and feed for finishing and included in genetic evaluation programs will be analyzed. Individual information on live ultrasound carcass measurements and frame will, also, be collected. After slaughter, carcass, beef quality traits and video image analisys (AVI) of muscle Longissimus will be obtained for estimation of beef quality attributes like color, marbling and pH. Evaluations with Near Infrared Technology (NIRS) will be made to quantify tenderness and lipid in Longissimus muscle. Laboratory analysis of tenderness and total lipids will be made to compare with AVI and NIRS data. Heritability and genetic and phenotypic correlations and genetic values will be estimated for all traits analyzed in this study. This research will provide precious information to development of auxiliary tools for genetic improvement of growth, carcass and meat quality traits in Nellore herds, and provide important information about variability and genetic value of founders and representative sires of this breed. (AU)