Chemical composition and nutritional value of leaves and pods of Leucaena leucocephala, Prosopis laevigata and Acacia farnesiana in a xerophilous shrubland

Abstract

The objective of this study was to determine the nutritional value of three leguminous trees heavily selected by goats in a xerophilous shrubland. Chemical composition and in vitro dry matter disappearance (IVDMD) of leaves and pods from leucaena (Leucaena leucocephala), mesquite (Prosopis laevigata), and huisache (Acacia farnesiana) is presented. Crude protein (CP) ranged from 17.3\% for leaves of huisache to 21.9\% for leucaena. The neutral detergent fiber (NDF) content ranged from 39.0 to 40.3 with no difference among fodder threes. Across tree species, mean IVDMD was 61.6\% for pods and 52.2\% for leaves. IVDMD for leaves was highest (p < 0.01) for leucaena (54.9\%) and lowest for huisache (47.3\%). Condensed tannins in an acetonic extract were highest for leaves of huisache (45.3 mg CE/g DM) and lowest for mesquite (25.9 mg CE/g DM). Pods and leaves of huisache presented the highest number of secondary metabolites, mainly related to hydroxybenzoic acid and flavonols; leucaena and mesquite presented mainly flavonols and anthocyanins. It was concluded that leaves and pods of leucaena, mesquite, and huisache constitute valuable forages for ruminant livestock due to their low fiber, high CP levels, moderate in vitro fermentation characteristics and high mineral content.