Chemical composition, phenolic content and in vitro gas production contants of forage of psyllid-resistant Leucaena species grown in Zimbabwe

Abstract

Leaves from Leucaena species L. esculenta, L. diversifolia, L. pallida, L. pulverulenta, L. salvadorensis, L. shannonii, L. trichodes and the interspecific hybrid L. Leucocephala x L. diversifolia that are resistant to the psyllid Heteropsylla cubana were harvested at the end of the rainy season (April) and the dry season (November) from two sites. The leaves were either sun or oven ( 50ºC) dried and subsequently analysed for concentrations of dry matter (DM), organic matter (OM), crude protein (CP), neutral and acid detergent fibres (NDF and ADF), lignin, extractable proanthocyanidins (PAs), soluble phenolics (SPs) and protein precipitating potential (PPP). In vitro gas production was measured over 72 hours. Season of harvest and method of drying had no significant (P>0.05) effect on the variables measured. Species significantly affected concentrations of CP, lignin, PAs, SPs and PPP. Cluster analysis based on content of fibre or content of polyphenolics or total gas produced identified L. shannonii, L. salvadorensis, L. esculenta and the intraspecific hybrid L. leucocephala x L. diversifolia as potentially good quality forages.



Key Words: Gas production, Heteropsylla cubana, leucaena, nutritive value, phenolic, tannin


(African Crop Science Journal: 2000 8(1): 63-76)