Effect of different processing methods on chemical composition and <i>in vitro</i> gas production of some browse plants for ruminant feeding

Abstract

Chemical composition and in vitro gas production parameters of four differently processed browse plants (Gmelina arborea, Leucaena leucocephala, Mangifera indica and Moringa oleifera) was investigated. The leaves of each plant were subjected to three processing methods; sun-drying, air-drying and fermentation. Chemical composition and in vitro gas production analyses were carried out. Results showed that processing methods had significant effect (p < 0.05) on all the parameters considered under chemical composition. Air dried and sun dried browse plants had higher (p < 0.05) dry matter content (89.68 and 89.75% respectively). Highest crude protein was recorded in air-dried browse plants (26.20%). Moringa oleifera recorded higher (p < 0.05) crude protein, ether extract and ash contents (35.60%, 14.17% and 13.50% respectively). Fermented browse plants had the lowest amount of tannin and saponin. Air-dried browse plants had higher gas production throughout the incubation period. Among the browse plants, the highest gas production (p < 0.05) was obtained in Moringa oleifera. Air and sun-dried browse plants recorded higher values for OMD (51.39%; 44.80%) and SCFA (0.46mmol; 0.35mmol). Air drying was the best method for maintaining nutrient content of forages while fermentation was the best for reducing anti-nutritional factors.

Keywords: Processing methods, chemical composition, in vitro gas production, browse plants