Factors affecting in situ dry matter degradability of tropical forage:: III.: Sample particle size

Samples of 1, 3 and 5mm of cameroon (Pennisetum purpureum Schum) and jaragua (Hyparrehnia rufa Ness) were incubated in nylon bags for 6, 24 and 96 hours in rumen of three fistulated steers in order to observe if particle particle size interferes on the parameter estimates of the dry matter degradation model in terms of incubation time t (DM deg=A-B.e(-ct)). The animals were daily fed with coast-cross hay (Cynodon dactylon x Cynodon nlemfuensis) ad libitum, concentrate (2.4kg) and mineral mixture (25g). It was observed that the cameroon kept its parameters independently, of particle size whereas the jaragua increased its degradation rare (parameter C) with lower particle size.