Associação entre produção de leite, duração da lactação, primeiro intervalo de parto e intervalo de parto com a morfometria de búfalas mestiças da raça Murrah por meio de análise multivariada

Abstract

The inclusion of body measurements of buffaloes as a selection criterion aiming at the improvement of production and reproduction can be a very promising method, since some reports in the literature have shown that some morphometric traits are related to animal’s potential. Although, there are few researches with this type of approaches, it is believed that the study of body measurements of buffaloes jointly, can be used to predict the animal’s potential and fitness to commercial exploitation. The multivariate techniques allow to analyze jointly several traits. Among them, we can be listed the Principal Component Analysis (PCA) and the Canonical Correlation Analysis (CCA). The PCA consists of reducing the dimensionality of the data and eliminating redundant information, allowing to identify the variables that contribute most to the expression of the total variance without the loss of originality of the data. The CCA aims to develop a linear combination in each of the sets of variables studied, such that the correlation between these two sets will be maximized. The objective of this study was to study the association between a set of body morphometric measures with milk production (MP), length lactation (LL), first calving interval (FCI) and calving interval (CI) of 99 Murrah crossbreed female buffaloes aiming to provide aids to selection’s process. In this study, the PCA results allowed six principal components were maintained, which they accounted for 94.69% of the data total variance. In the ACC among the body morphometric traits with the set of the productive and reproductive traits, the first canonical function was significant (P <0.05), presenting a moderate association between the groups of traits studied (0.56), indicating that both groups are considered dependent. Thus, these techniques can be used to study the relationship between morphometric measures and productive and reproductive potential of the animals, aiming to contribute to the selection of biotypes that meet the demands of production systems.