Abstract: An In vitro gas production study was conducted to determine the effect of age and soil treatments on fermentation characteristics of Sorghum almum, Commelina benghalensis and Vicia villosa Roth. The soil treatments were: T1-not fertilized and T2 received DAP fertilizer. Forage samples used were obtained from herbage materials harvested at 6, 8, 10, 12 and 14 weeks of growth. Dry samples (65 C for 24 h, 200 mg DM) of the harvested materials, were incubated in glass syringes with rumen fluid obtained from 2 Friesian steers fitted with permanent fistula. The gas volumes were recorded at 0, 4, 6, 12, 24, 36, 48, 72, 96 and 120 h and the data fitted to the model P = a + b (1–e-ct) after correction with blanks using in vitro gas fit-curve program. Forage chemical analyses were done according to standard procedures. The resulting data was analyzed using SAS. Results showed that nutrient composition of this forage, varied with both age at harvest and treatment. The overall means of the fermentation fractions (b) and (a + b) in T2 were higher than in T1 (p< 0.01) across the 3 forages. Strong correlation was observed between chemical composition and gas production. Pattern of gas production was strongly influenced by both treatment and age at harvest. It was therefore, concluded that, age at harvest, negatively affected rumen fermentation of these forages. Application of fertilizer improved in vitro gas production, suggesting enhanced fermentation.
Lanyasunya , T.P. Wang , H. Rong , E.A. Mukisira , S.A. Abdulrazak and N.K. Kibitok , 2007. Effect of Maturity and Fertilizer Application on in vitro Gas Production Characteristics of Sorghum almum, Commelina benghalensis and Vicia villosa Roth . Journal of Animal and Veterinary Advances, 6: 943-949.