Effects of stage of maturity on chemical composition and apparent digestibility of buffel grass and gamba grass

SUMMARY Well established pastures of buffel grass (Cenchrus ciliaris var. Biloela) and gamba grass (Andropogon gayanus var. bisquamulatus) were slashed early in the rainy season. The subsequent regrowths when 4, 6 and 8 weeks old, were examined for proximate composition and digestibility, and the voluntary intake of forage assessed using the West African Owarf sheep. For both grasses, dry matter (OM) and crude fibre (CF) contents increased, whereas crude protein (CP), ether extract, ash and P decreased with advancing maturity; calculated nitrogen free extral.:t was maximal at 6 weeks of regrowth. At 4 weeks, buffel grass with 63.2 per cent total digestible nutrients (TON) and 6.22 per cent digestible crude protein (OCP) and gamba grass with 63.2 per cent TON and 6.13 per cent OCP were of good quality. At 8 weeks, TON contents decreased by about 14 and 12 per cent while OCP decreased by 50 and 40 per cent of the values at 4 weeks for buffel grass and gamba grass, respectively. The voluntary intake of both TON and ocr were 140 and 130 per cent of maintenance requirements at 4 weeks of regrowth for buffel grass and gamba grass, respectively. At 8 weeks, TON intake was adequate for maintenance requirement. It would thus appear that these grasses should be harvested or grazed between 4 and 6 weeks of regrowth.