In a preliminary study on the nutritional value of seven multipurpose trees (MPTs), currently showing potential use in agroforestry systems in Zimbabwe, crude protein values ranged from 189 g kg1 DM in Flemingia macrophylla to 292 g kg1 DM in Acacia angustissima. Acid detergent fibre (ADF) content was low especially in Sesbania sesban (99 g kg1 DM), while ADF contents in Flemingia macrophylla (277 g kg1 DM) and Cajanus cajan (255 g kg1 DM) were the highest. The MPTs had ash contents ranging from 58 g kg1 DM in Flemingia macrophylla and Cajanus cajan to 95 g kg1 DM in Sesbania sesban. MPTs with detectable amounts of condensed tannins were Calliandra calothyrsus (17.9 g kg1 DM), A. angustissima (10.3 g kg1 DM) and Flemingia macrophylla (3.4 g kg1 DM). These MPTs were poorly degraded in the rumen compared to the other four species. The presence of condensed tannins could lower their potential as ruminant feeds.
Tag: leaves
Nutrient intake and utilisation by goats fed dried leaves of the shrub legumes Acacia angustissima, Calliandra calothyrsus and Leucaena leucocephala as supplements to native pasture hay
Thirty-six indigenous goats were used to determine the potential of sun-dried leaves of the shrub legumes Acacia angustissima, Calliandra calothyrsus and Leucaena leucocephala as supplements to native pasture hay (NPH). The dried leaves were included at the rates of 80, 160 and 320 g/head/day. Cottonseed meal fed at the same levels, and NPH fed alone were included as controls. Among the browses, C. calothyrsus had the lowest N content of 19.0 g/kg dry matter (DM) and A. angustissima the highest of 35.0 g/kg DM. The leaves from the legumes had significantly less N and higher cell wall, neutral detergent insoluble N (NDIN) and acid detergent insoluble N (ADIN) contents than cottonseed meal. The values of NDIN as a fraction of total N were 19, 456, 526 and 816 g/kg for cottonseed meal, L. leucocephala, A. angustissima and C. calothyrsus, respectively.Proanthocyanidin contents were 33, 196 and 134 g/kg DM for A. angustissima, C. calothyrsus and L. leucocephala, respectively. Type of supplement did not affect (P>0.05) NPH, total and digestible DM intakes although NPH intake was depressed (P<0.05) at the highest level of supplementation compared to the first two levels. Animals fed legumes excreted significantly more (P<0.001) faecal N (g/kg N intake) than animals consuming cottonseed meal. The reverse was observed for urine N. Among the legumes, C. calothyrsus had significantly higher (P<0.001) N in faeces (958 g/kg N intake) than A. angustissima (630) and L. leucocephala (615). Significant (P<0.05) correlation coefficients were obtained between proanthocyanidins (PAs) intake and faecal N, NDIN and ADIN (0.535, 0.501 and 0.786, respectively). Regressing digestible N on N intake indicated that A. angustissima and C. calothyrsus tannins had significant effects on the digestion of dietary N. The animal responses were discussed in relation to PAs content. It was concluded that both the type and level of PAs were important determinants of the animal responses.