It iswell knownwhat genetic and nutritional factors affect growth and meat quality, but there is less information
related to interactive importance of them during the productive process. These systems are mainly based on
rangelands affecting animal growth in early stages of life thus producing smaller cattle and reduced retail yield
comparing with well grown calves. During the last ten years, Uruguayan livestock production systems have
been intensified using improved pastures, concentrates and better genetic. The main breeds in Uruguay are
Hereford, Angus and their crosses. These British breeds are under genetic evaluation programs which consider
carcass trait parameters. It is important for beef industry to knowif interactions between genotype and nutrition
during growth and fattening phases are influencing production, efficiency, carcass weight and meat quality
attributes. The aim of this article is to present information obtained under different feeding strategies during
the post weaning and fattening and their influence on those attributes.