On-Farm Preference by West African Dwarf Goats and In Vitro Digestibility of Centrosema, Pueraria, Napier Grass and Guinea Grass Forages

Abstract

Forage from legumes (Centosema molle; Pueraria phaseoloides) and grasses (Pennisetum purpureum; Panicum maximum) were studied for proximate composition, acceptability, preference, and in vitro gas production characteristics using eight West African dwarf (WAD) goats. Dry matter ranged (P < 0.05) from 19.2 g/100 g in P. purpureum and P. maximum to 31.0 g/100 g in C. molle. Crude protein (CP) ranged (P < 0.05) from 12.3% in P. maximum to 18.8% in P. phaseoloides. Neutral detergent fibre (71.3 ± 1.94 g/100 g DM) was similar (P > 0.05) amongst the forages. The number of visits and bites per minute and dry matter intake (DMI) varied (P < 0.05) from the least for C. molle to the highest for P. maximum. Number of visits and bites by goats had positive correlation (r = 0.79; P = 0.05). Mean Coefficient of preference (COP) was 0.93 ± 0.048 while, P. maximum recorded 1.19 COP with a preference ranking of: P. maximum > P. phaseoloides > P. purpureum > C. molle. Gas production from P. phaseoloides was consistently highest at 3, 6, 9, 12, 15, 18, 21 and 24 hours incubation periods. Similarly, P. phaseoloides produced the highest volume of methane (17.0 mL) with the least (12.0 mL) from P. maximum and C. molle. The potential gas production varied from 81.2 mL/200 g DM for C. molle to 560.8 mL/200 g DM for P. maximum while, gas production rate was similar (P > 0.05) amongst the forages. It was concluded that the CP contents of the forages were adequate since they were above the recommended 8% needed to provide the required ammonia for optimum rumen microbial activity.