FORAGE VALUE OF NATIVE AND INTRODUCED BROWSE SPECIES IN TANZANIA

The nutritional value of Leucaena leucocephala (Lam.) de Wit was compared with that of 3 browse species native to western Tanzania: Antidesma venosum Mey. & Tul., Margaritaria discoides Baill., and Phyllanthus reticulatus Lodd. Foliage samples were collected monthly throughout the dry season from replicated sites on 3 different soil types and analyzed for crude protein, total ash, and in vitro dry matter digestibility. The crude protein content of L. leucocephala (17.60-29.69%) was higher (P<.05) than that of the native species (8.51-16.33%) throughout the study. Phyllanthus reticulatus had the highest crude protein of the native species. Abscised leaves had only half the crude protein of green leaves of the same species. All species showed a significant increase in crude protein when new leaves appeared. L. leucocephala had as much or more ash (6.96-9.77%) than the native species. Margaritaria discoides was more (P<.05) digestible (56.75-74.06%) than all other species on all dates but one. The in vitro dry matter digestibility of green and abscised leaves of the same species did not differ (P<.05) until July when green leaves of M. discoides, were more digestible. Soil type affected the in vitro dry matter digestibility of all species except A. venosum (P<.05), but did not affect crude protein values. Both the native species and L. leucocephala can contribute significantly to meeting animal nutrient demands in the dry season.