Análise multivariada das características de carcaças de bovinos da mesorregião do Norte de Minas Gerais

Abstract

The objective was to group and characterize bovine carcasses according to their sexual status. Data based on the slaughtering romaneio with information of 15,002 carcases of ringed cattle from 32 municipalities of the North of Minas Gerais were used. The variables analyzed were: warm carcass weight, carcass conformation, subcutaneous fat score, sexual condition, number of incisor teeth and presence of lesions caused by vaccines. Cluster analysis was used to group the animals, which took into account all variables analyzed. The number of clusters were not specify prior to the analysis, the Statistica program used automatic methods, based on cross validation, to choose a better clusters solution. The number of animals affected by lesions caused by vaccines was verified on line H of inspection in the slaughterhouse. It was also used the dissimilarity measure through the Euclidean distance coefficient to calculate the degree of similarity between the clusters and also the unit circle for the study of the influence of the active variables on the variable lesions caused by vaccines (supplementary variable). Four clusters were formed according to the analysis. Females were grouped in all clusters. The castrated appear in three clusters, the discard cows in two. Non-castrated males appear in only one group, indicating that they are less similar to each other. Age (DIP), subcutaneous fat score and carcass weight influenced the highest number of lesions caused by vaccines. The sexual condition of cattle is not, in itself, only responsible for standardizing the carcass characteristics of the different sex classes. Carcasses from older cattle, with higher slaughter weight and higher subcutaneous fat scores have a greater number of lesions caused by vaccines due to the longer stay in the production system.