Metanalysis for carcass traits of cattle from different genetic groups

The meta-analysis methodology was applied in this stud), to evaluate factors that affect the carcass quality components in beef cattle (rib eye area - AOL and fat thickness - EGC, measured between the 12(th) and the 13(th) ribs) and to compare them in different genetic groups. Data from 215 measures of AOL and 209 measures of EGC, from 65,174 animals, extracted from 36 papers published between 1985 and 2000 were used. The Restricted Maximum Likelihood Method and an animal model that considered AOL and EGC as junctions of the fixed effects of country from where the data come from; animal category; feed system; measure methodology: Bos indicus. british and continental Bos taurus gene contribution,- age and weight at measure, were used. The observed averages for AOL and e EGC were 63.5cm(2) and 4.2mm, respectively. The animals were in average 552.22 days old at the measure of the characteristics and had 468.47kg of live weight. The use of meta-analysis permitted to get generalized conclusions about AOL anti EGC: animals rose in the EUA presented values significantly superior for AOL and EGC when compared with those rose in Australia and Brazil; castrated and the entire males presented bigger AOL measures (do not differing among them) compared to females, and females presented bigger EGC. The feed system, con fined and do not confined, were superior to the greasing system. The Continental Bos taurus genotypes presented bigger AOL values, British Bos taurus presented bigger EGC values, and Bos indicus presented intermediate values. The measures taken in the carcass (pos mortis) and by ultra son (in vivo) were not different. The increase in the characteristics decreased with the age and live weight increase.