Canonical correlations among chemical, physical and morphological characteristics of Xaraés palisadegrass under rotational grazing

Abstract

In forage evaluation experiments, the assessment of adaptive and productive characteristics of genotypes is generally prioritized over qualitative responses such as nutritive value and voluntary intake. Methods that are capable of characterizing forage quality through the physical resistance to degradation have been proposed, including grinding resistance and shearing resistance. Canonical correlations establish a multivariate approach associating multiple variables depicting inter-relations studies between groups of dependent and independent variables. The objective of this research was to assess the degree of association among groups of quality-related responses of grazed Xaraés palisadegrass forage using canonical correlations among morphological, chemical and physical characteristics of forage samples. Only the first canonical pair was significant in the correlation between the morphological and physical variables. Between morphological and chemical variables, none of the canonical pairs were significant. In the canonical correlation between physical and chemical variables, the only significant canonical pair was the first, where forage with lower shearing resistance of leaves and stems, had higher concentration of crude protein in leaves and whole forage, lower concentration of neutral detergent fiber in leaves and whole forage, and higher digestibility of leaves and stems. The study of canonical correlations allowed to explain the relation between groups of qualitative variables of grazed Xaraés palisadegrass, and is highly significant between morphological and physical variables, and between physical than chemical variables.