Nutritive value of some tropical grasses used by traditional small farms in the highlands of Burundi.

The objective was to estimate--according to the French feeding system--the nutritive value of three tropical grasses (Eragrostis olivacea, Setaria sphacelata and Tripsacum laxum) used in traditional small farms of Burundi. Dry matter (DM) yield was monitored on anti-erosive hedges or on small fields in 60 small farms for eight consecutive years. DM intake and digestibility values were measured on seven steers or seven male sheep. Degradability values were determined on three sheep. S. sphacelata exhibited higher DM yield (t ha(-1)), energy (UF, kg(-1) DM) and protein (PDI, g kg(-1) DM) values (17.3, 0.73 and 68, respectively) than T. laxum (9.11, 0.64 and 47) and E. olivacea (not determined, 0.46 and 42). The UF and PDI intakes of these grass species were able to meet only 51% to 92% of the energy and 59% to 133% of the protein requirements for maintenance of the experimental animals.