Effect of Tree Leaves on Rumen Fermentation, Microbial Count and Blood Urea Nitrogen of West African Dwarf Goats

Abstract

This experiment was carried out to assess the effect of Azadirachta indica, Newbouldia laevis and Spondias mombin leaves on rumen fermentation, microbial count and blood urea nitrogen (BUN) of West African Dwarf (WAD) goats. Sixteen WAD bucks (11.6 ? 0.9 kg in body weight) were allocated to 4 treatments: 1) Control and 2) 40 g/day of Azadirachta indica, 3) 40 g/day of Newbouldia laevis and 4) 40 g/day of Spondias mombin leaves arranged in a completely randomised design. The ground leaves were included in concentrate diets served on dry matter basis at 2% of body weight while Panicum maximum was fed ad libitum. The control diet had no tree leaves. Data were collected on chemical composition, rumen fermentation and microbial ecology, and BUN. Saponin was highest (P < 0.05) in S. mombin (8.14%) while A. indica and N. laevis had 5.78% and 1.56%, respectively. Rumen ammonia nitrogen was least (P < 0.05) in goats fed A. indica (8.35 mg/dL) while the highest (P < 0.05) total volatile fatty acid (TVFA) was obtained from goats fed S. mombin with 125.51 mM. Goats fed N. laevis yielded the highest (P < 0.05) acetate with 70.65 mol/100 mol while propionate production was highest (P < 0.05) in the rumen of goats fed S. mombin (27.15 mol/100 mol). Viable bacteria count was lowest (P < 0.05) in rumen of goats fed A. indica (3.95?1012 cfu/ml) while the least (P < 0.05) protozoa population was obtained from the rumen of bucks fed S. mombin (4.18?109 cfu/ml). All goats in the treatments containing tree leaves had higher (P < 0.05) and a rapid increase in BUN between 0 and 6 h post feeding when compared with the Control. It is concluded that feeding ground leaves of S. mombin to goats increases rumen total volatile fatty acid and propionate production and reduces the protozoa population.

Keywords

• saponin
• rumen
• volatile fatty acids
• microbial
• goats