In vitro gas production and dry matter degradation of four browse leaves using cattle, sheep and goat inocula

Abstract

The effects of rumen inoculum from Bunaji cattle, West African Dwarf (WAD) sheep and WAD goat on the in vitro gas production and dry matter (DM) degradation of Moringa oleifera, Millettia griffoniana, Enterolobium cyclocarpum and Gmelina arborea leaves were compared in an in vitro study using incubation periods ranging from 0 – 48 h. Oven-dried samples of the leaves were incubated in three replicates with each inoculum source and incubations run at two consecutive times to make six replicates per treatment for estimation of the kinetics of gas production using non-linear equation. Leave samples were analyzed for crude protein (CP), lignin (ADL), acid (ADF) and neutral (NDF) detergent fibres. Concentrations of CP (165 – 247 g.kg-1 DM), NDF (413 – 538 g.kg-1 DM) and ADF (300 – 346 g.kg-1 DM) differed among species. Inoculum sources varied (P < 0.05) in volume of gas production at 12 and 24 h along the incubation but not at later incubation times of 36 and 48 h. Gas production between cattle, sheep and goat were correlated (r = 0.98; P < 0.001). Kinetics of gas production differed (P < 0.05) among inoculum sources with cattle inoculum showing a shorter (P < 0.05) lag time and higher (P < 0.05) rate of fermentation. Gas production also varied (P < 0.05) among browse species with M. oleifera recording the highest volume of production. M. oleifera and E. cyclocarpum were higher (P < 0.05) in dry matter degradation than M. griffoniana and G. arborea irrespective of inoculum source. Results indicated that in vitro gas production and dry matter degradation of the forages varied due to browse species and not inoculum source. Rumen fluid from cattle, sheep and goats could therefore, serve as inoculum source for the screening of these forages for ruminants.