The digestibility and voluntary intake of six varieties of Panicum

Abstract

The digestibility and voluntary intake of P. coloratum CV. Kabulabula, P. coloratum var. Makarikariense CV. Burnett and C.P.I. 13372, P. maximum var. trichoglume CV. Petrie Green Panic, P. maximum cv. Coloniao guinea grass and Hamil were measured with sheep in metabolism pens. Each grass was cut eight to ten times at different growth stages and times of the year. Varieties differed (P<0.01) in their dry matter and organic matter digestibility but the maximum mean difference between varieties was only 2.8 and 3.4 per cent respectively. There were large differences in voluntary intake between grasses. P. maximum cv. Hamil had a voluntary intake 50 and 27 per cent greater than P. coloratum cv. Kabulabula when both had p dry matter digestibility of 50 and 60 per cent respectively. Voluntary intake of digestible organic matter of P. maximum CV. Hamil was 26 per cent higher than that of P. coloratum CV. Kabulabula. The higher intake of P. maximm occurred despite its having higher silicon percentages than P. coloratum. It was concluded that because of the biased relation between intake and digestibility selection of grasses on the basis of digestibility determinations alone could be a misleading guide to their nutritional value.