Chemical composition of some Iberian Mediterranean leguminous shrubs potentially useful for forage in seasonally dry areas

Abstract

The chemical composition of herbage produced by legume shrubs was determined to appraise their potential value for forage. Six species were assessed for seasonal variation in the proportion of leaves, and ash content, neutral detergent fibre (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), and crude protein (CP) concentrations. Hippocrepis balearica, Medicago citrina, Medicago strasseri, and Medicago arborea showed an average ADF content <25% and an average crude protein content >18%. The chemical composition of Medicago strasseri was very close to that of Medicago arborea throughout the year. In winter and summer, Medicago citrina showed lower ADF and ADL content than Medicago arborea. Therefore, Medicago citrina could be useful as a summer or a winter forage. Hippocrepis balearica showed higher crude protein content in summer and lower ADF content in winter than Medicago arborea, but significantly higher ADL contents (9.7% to 12.5% versus 7.1% to 9.4%). Therefore, Hippocrepis balearica could be a good option as a winter and summer forage, although further studies are necessary to elucidate the possible detrimental effect of lignin in forage digestibility. Coronilla juncea and Cytisus arboreus showed an average ADF content >30% and an average crude protein content <15%. Coronilla juncea showed good chemical composition in winter (28.7% ADF, 9.0% ADL, and 12.6% crude protein) making this species potentially useful as a winter forage.