Navas-Camacho et al., 1993. Livest. Res. Rural Dev., 5 (2)

Multi-purpose trees, as components of production systems in the tropics, play an important role in soil conservation and provision of shade, as well as being an important alternative as a source of protein-rich forage source. They are also more drought-resistant than grasses. The present experiment aimed at evaluating the effect on rumen function of supplementing sheep with three levels (0, 100 and 300g/d) of dry leaves of a tree legume (Enterolobium cyclocarpum), which is naturally consumed by ruminants when branches are accessible to them. The main results of the experiment were the following: It appears that dietary and maybe bacterial amino acid absorption at the small intestine was increased by supplementation with leaves of E. cyclocarpum, as indicated by the positive correlation between wool growth rate and intake of E. cyclocarpum. Supplementation with low levels (100 g/d; approximately 10% of total dry matter intake) of E. cyclocarpum, increased voluntary feed intake, digestible matter intake and nitrogen balance by increasing nitrogen digestibility. However, the high level of supplementation (300 g/d; approximately 34% DMI) reduced digestible dry matter intake, which, could be an important limitation to its inclusion in the diet at high levels. The population of rumen fungi was increased by supplementation with low and high levels of leaves of Enterolobium cyclocarpum. Rumen ciliate protozoa were increased by the inclusion of low levels in the diet (10% of DMI), but strongly decreased in sheep receiving high levels of supplementation (34% of DM). Rumen bacteria showed no response to supplementation. The presence of saponins in leaves of Enterolobium cyclocarpum may have contributed to the reduction in protozoa numbers in the rumen fluid, particularly Holotrich protozoa.