Avaliação meta-analítica de sistemas de produção no ganho de peso e peso de carcaça de ovinos de corte

Abstract

A meta-analytical study was carried out in order to evaluate the performance and characteristics of ovine carcass in function of the finishing system. Articles published in indexed journals were selected that presented results of experiments comparing production variables of finished ovine in different production systems. The parameters used for the selection of the articles were: comparison of systems by pasture, pasture supplemented and in confinement; cutting ovine; finishing phase; weight gain responses and warm and cold carcass weights. For a better quality of the data, only articles published in journals classified by the National and International Periodicals Classification System (Qualis) of the Coordination for the Improvement of Higher Level Personnel (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES), equal to or above B1, were selected. The database used for the meta-analysis consisted of 38 scientific papers from twelve countries, published between 2000 and 2015, totaling 1589 animals, from pure and cross-breeding genetic groups. The meta-analysis was performed for the characteristics of average daily weight gain, warm carcass weight and cold carcass weight. The publication bias was evaluated visually and statistically to observe if there are any publication vices, that is, if the bibliographic search was not in-depth, and the presence of discrepant observations through the funnel plot and the order correlation asymmetry tests adjusted from Begg and regression from Egger. The studies were included in a quantitative analysis when sufficient data were provided to estimate the average and standardized differences between the production systems and their 95% confidence intervals. There was no heterogeneity of variance between the studies, nor significant differences between finishing systems, in addition to absence of publication bias. However, further studies are needed to better elucidate and prove the results of this meta-analysis.