Seasonal variations and biplot analysis of feed quality parameters, minerals, and gas-methane production in common shrub species

Abstract

In various parts of the world, shrubs are used as a source of feed for ruminants. Ligneous species play a significant role in animal feeding, especially during the summer, autumn and winter months. In this study, seasonal variations in feed quality parameters of 15 different shrub species were investigated. Shrub leaf samples were collected on the 15th of each month. In each season, samples of three months were equally mixed (Spring -Summer -Autumn -Winter). All species had sufficient levels of feed quality parameters for grazing animals. ADF, NDF, condensed tannin, crude oil and crude ash contents increased, crude protein, gas and methane production, metabolic energy and organic matter digestibility decreased with the progress of the seasons from spring through winter. Biplot analysis is a multivariate analytical technique that visualises the relationships among genotype traits. GT biplot analysis allowed reliable identification of the relationships between the investigated traits and the selection of superior species for selected feed quality parameters. The findings indicate that ligneous species can effectively substitute herbaceous ones and fulfill most nutritional requirements of grazing animals across summer, autumn, and winter.