Utilization of Some Edge-Row Plants as Forage in Nigeria

Abstract

In Nigeria, pasture is routinely available such that it is abundant in the rainy season and very scare in the dry season. Browse trees are not seasonal and a number of the browse trees are acceptable by cattle, sheep and goats as supplements to the scanty pasture in the off-season. It is against this background that the present study was carried out to assess the nutritive value of some relatively unexploited browse plants including neem (Azadirachta indica), almond (Terminalia catappa), mango (Mangifera indica) and bitter leaf (Vernonia amygdalina). Chemical composition of the forages was determined for CP, NDF, ADF and ADL. Presence of secondary metabolites including tannin, saponin and steroids was determined qualitatively. Residue obtained from qualitatively determined secondary metabolites (extracted) and that of whole samples (unextracted) were further subjected to in vitro gas production at 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22 and 24 h incubation periods to elicit extent of degradability. Results indicate that CP, NDF, ADF and ADL ranged from 10.5-21.8, 34.5-38.5, 21.0-26.3 and 6.5-15.5% respectively. Saponin was present in mango tree while all samples showed presence of condensed tannin and steroids. Extracted residue enhanced degradability as total gas production, metabolizable energy, organic matter digestibility and methane production were more than those of the whole browse samples. It is concluded that browse trees have nutritive value and the presence of secondary metabolites in them are assets for the reduction of methane capable of increasing environmental pollution.