Erythrina variegata quality in the Cauto Valley, Cuba

Abstract

This experiment has examined the effects of age of regrowth (60, 120 or 180 days) and season (dry or rainy period) on the nutritional quality of roughage from Erythrina variegata harvested in the Cauto Valley, Cuba. A randomized block design with three replicates was used. Proximate and mineral composition, in vitro and in situ dry matter digestibility were evaluated, in addition to the secondary metabolites (tannins, phenols, verbascose, stachyose, raffinose, flavonoids, triterpenes and steroids) at different ages of regrowth, in both seasons of the year. There was a significant interaction between treatments for most of the nutritional components or digestibility coefficients analyzed, although the pattern followed with age of regrowth was similar in both seasons. The gas production increased with the age of regrowth and the higher value was obtained during the dry season, while the lag phase was longer in the rainy season. The results of this study show the marked effect of climatic factors on the nutritive quality of E. variegata. In general, as maturity was increased the concentrations of secondary metabolites also increased, but only condensed tannins were close to the limits for which ruminal fermentations can be affected. All these aspects should be considered in this species when it is used in animal feeding.