Study of relationship among expected progeny differences (EPD) with productive and meat quality traits of Nelore cattle

Abstract

Among the technologies that have been used to increase the efficiency of meat production chain, genetic selection of breeding animal, through breeding programs, is a tool of great importance. In this sense, growth and reproductive characteristics have been prioritized, but little emphasis has been given on the correlation of these characteristics with the quality of meat, especially in Nellore cattle. Thus, this work will be performed to assess the relationship of different characteristics used as selection criteria in beef cattle on physiological characteristics, performance, carcass and meat quality of feedlot finished Nellore cattle. They will be confined 192 non-castrated males, which have results of genetic evaluation for traits related to growth (weight gain and weight at 18 months), sexual precocity (scrotal circumference and / or early pregnancy probability) and muscularity (visual assessment of muscularity or loin eye area). During the feedlot phase (about 120 days), the animals will be evaluated for performance (weight gain, feed intake and feed efficiency) and carcass characteristics by ultrasound, besides of termorregulation traits by infrared termography. In addition, blood samples will be collected for evaluation of plasma metabolites. At the end of the experiment, the animals will be slaughtered and evaluation of the retail yield, bones and trimmings. Longissimus muscle samples will be collected for evaluation of gene expression related to calpain and calpastatin, and also morphometric muscle profile. Samples will be colleted for evaluation of instrumental and sensory characteristics related to meat quality. We expect that these results could provide important information for the productive chain of Brazilian beef, helping them to (re)direct their production systems to increase system profitability and quality of meat. (AU)