VOLUNTARY INTAKE AND DIGESTIBILITY BY SHEEP AND GOATS OF WHOLE-PLANT, LEAF AND STEM FRACTIONS OF PENNISETUM-PURPUREUM SCHUM

Napier grass (Pennisetum purpureum Schum.) was cut after 6 weeks of regrowth, oven dried at 65-degrees-C for 48 h after field drying for 3 days. Herbage was hand separated into whole-plane (WP), leaf (LF) and stem (ST) fractions. Each of the three diets was offered to four West African Dwarf (WAD) sheep and four WAD goats to measure voluntary dry matter (DM) intake and apparent DM, crude protein and crude fibre digestibility coefficients. Sheep and goats consumed more (P < 0.05) LF than WP and ST. Daily DM intake by sheep fed WP (46 g kg-1 W0.75; W = live weight) was significantly higher (P < 0.05) than ST (30 g kg-1 W0.75), but intake by goats fed WP (32 g kg-1 W0.75) and ST (28 g kg-1 W0.75) was not. Sheep consumed significantly more (P < 0.05) LF (67 vs. 54 g kg-1 W0.75 d-1; d = day) and WP (46 vs. 32 g kg-1 W0.75 d-1) than goats. Differences in apparent DM digestibility for sheep (73%) and goats (76%) were not significant (P > 0.05). However, goats digested crude protein (66 vs. 61%) and crude fibre (80 vs. 76%) more efficiently (P < 0.05) than sheep. Overall DM digestibility coefficient of ST (78%) was significantly higher (P < 0.05) than that of LF (73%) and WP (73%).