Rumen fermentation characteristics of west African dwarf goats fed enzyme supplemented total mixed ration in the dry season

Abstract

The study was conducted to investigate the effect of exogenous enzyme additive on rumen environment parameters of West African Dwarf (WAD) goats fed total mixed ration (TMR) for a period of 70 days. Four experimental diets were formulated with enzyme included at 0.0, 0.2, 0.4 and 0.6 g/kg dry matter to constitute treatments 1,2, 3 and 4 respectively. Sixteen growing WAD goats were subjected to the four dietary treatments in a completely randomized design. Rumen fluid was collected from the goats before the commencement and at the end of the feeding trial. Data were collected on rumen pH, ammonia nitrogen, volatile fatty acids (VFAs) production and microbial population. Enzyme additive significantly (p<0.05) affect the total VFAs, propionic acid and butyric acid production with the highest values (86.23, 26.17, 14.87 Mm/100ml) for the three respectively obtained at T4(0.6g/kg). The bacteria count was significantly highest (5.20 × 10⁶cfu/ml) at T3 although not statistically different from what was obtained at T4. A total of 5 bacteria (Bacteroides, Clostridium, Fusobacterium, Streptococcus and Peptococcus spp.), 1 fungus (Aspergillus spp.) and 2 protozoa (Holotrich spp. and Trichuris spp.) species were isolated from the rumen at the end of the study. It was therefore concluded that exogenous enzyme containing cellulase, xylanase and beta glucanase can be included in a TMR for WAD goats at 0.4g/kg for increased bacteria count and total VFAs production.

Keywords: Exogenous enzyme, Total mixed ration, Goats, Rumen fluid, Microbial population