Yield, chemical Composition and In Vitro Ruminal Fermentation of the Leaves of Leucaena Leucocephala, Gliricidia Sepium and Trichanthera Gigantea as Influenced by Harvesting Frequency

This study was designed to evaluate the effect of cutting frequency (6-, 8-, and 12-week intervals) on biomass yield, chemical composition, and in vitro ruminal organic matter digestibility (IVOMD) of Gliricidia sepium, Leucaena leucocephala, and Trichanthera gigantea leaves. Leaves were harvested from trees growing in three different locations in Trinidad; University Field Station (UFS) at Valsayn, Sugar Cane Feeds Centre (SFC) at Longdenville and Centeno Livestock Station (CLS), at Centeno. Three species; (G. sepium, L. leucocephala, and T. gigantea) were compared at UFS while – two species (Gliricidia sepium and T. gigantea) were compared at CLS. At SFC, only L. leucocephala was evaluated. At UFS, biomass yield for leaves harvested at 12-week cutting interval was highest (P < 0.05) for G. sepium (16,440 kg/ha) and lowest for L. leucocephala (4,821 kg/ha). At CLS, however, biomass yield was highest for T. gigantea at 12-weeks (3,844 kg/ha). At SFC, there was a decline (P < 0.05) in crude protein (CP) content of L. leucocephala leaves as cutting intervals increased. In vitro organic matter digestibility (IVOMD) was highest in G. sepium leaves (710 g/kg DM) and lowest in T. gigantea leaves (340 g/kg DM). Crude protein (CP) content and IVOMD were highest in leaves harvested at 6-week cutting interval. Crude protein content and fibre levels (ADF, NDF, ADL) were highest in the leaves of L. leucocephala at UFS and SFC. Soluble condensed tannins (SCT) were highest in L. leucocephala leaves. It was concluded that cutting interval had no effect on IVOMD. However, biomass yield increased with increasing cutting interval.