Effect of Processing on Nutrients and Rumen Microbial Characteristics of WAD Sheep Fed Gmelina arborea Leaf Based Diets

Abstract

Low pasture quality and quantity adversely affect the performance of ruminants in the tropics. This necessitated the search for other feed resources that could augment the deficit, particularly, in the dry season. However, some of these feed resources contain phytochemicals which if not properly processed could be detrimental to ruminants. This study was carried out to determine the effects of processing on nutrients, phytochemicals and microbial characteristics of WAD sheep fed processed Gmelina arborea leaf based diets. Gmelina arborea leaves (GAL) were harvested and used as fresh, chopped, sun-dried, air-dried and boiled-dried. Nutrients and phytochemicals were determined from samples. Rations were comprised in the following proportions; T1 (50% Penniseum purpureurn: 50% fresh Gmelina arborea leaves), T2 (40% Penniseum purpureurn: 60% chopped Gmelina arborea leaves), T3 (40% Penniseum purpureurn: 60% air dried Gmelina arborea leaves), T4 (40% Penniseum purpureurn : 60% sun dried Gmelina arborea leaves), T5 (40% Penniseum purpureurn : 60% boil dried Gmelina arborea leaves). Forty WAD sheep (6-8 months) were randomly assigned to one of the rations with eight sheep per group in a completely randomized design. Ninety days post-feeding, rumen liquor was collected for microbial assay using standard procedure. The CP and calcium were increased in T1 and T2 compared to others except for NFE which was reduced. Tannin and saponin increased in T1 and T2 but reduced in T5. Streptococcus spp was absent in T5 compared to T1 and T2. Lower total bacteria count was observed in T5 compared to other treatments. Boiled-drying reduced the crude protein and phytochemicals contents of Gmelina arborea leaves with reduction in total bacteria count in the rumen.