Abstract
Brazil has the largest commercial cattle herd in the world and is the largest exporter of beef, even filling this important economic position, the beef cattle industry is being pressured to show increases in productive efficiency. The carcass and meat traits are very important because they are the ones that determine the price and access to new markets. Beef traits such as tenderness, fat thickness, intramuscular fat and ribeye area are determinants of carcass quality and meat. Currently, there is a continuing and growing concern among the population and public health agencies regarding the excessive consumption of fat, especially animal fats, as well as the type of fat or fatty acid profile of the meat, and its impact on consumer health. The genetic improvement for carcass characteristics, meat and fatty acid profile has not been practiced because of measurement difficulties and be costly. This objective of this project was to study the genetic associations between meat fatty acid profile with carcass and meat traits in Nellore cattle. Data from meat tenderness, fat thickness, intramuscular fat, ribeye area and meat fatty acid profile of approximately 2,000 animals of Nellore breed finished on feedlot, aged next two years, from farms that integrate three breeding programs, will be utilized. The models to be used for the estimation of (co)variance components and genetic parameters will include the random effects of additive direct genetic, maternal genetic effect and maternal permanent environment (only for weaning weight), the fixed effects of contemporary group and other effects fixed, depending on the traits. The importance of effects such as age and / or weight of the animal, as well as number of days in the feedlot will be tested. The (co)variance components will be estimated using the restricted maximum likelihood method. This project provides an opportunity to study the meat fatty acid profile of Nellore cattle and their association with meat tenderness, fat thickness, intramuscular fat and ribeye area.
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