Early-and-late-heading varieties of Chloris gayana and Setaria sphacelata were evaluated to allow the selection of superior germplasm. Chemical constituents did not differ (P0.05) between species or varieties within species except for cellulose and hemicellulose contents which showed differences within (P0.05) but not between early- and late-heading varieties. In vitro digestibility values were significant between dates of cutting (P0.01) but not between (P0.05) varieties. In the in vivo trials significant differences (P0.05) were observed in metabolisable energy (ME) and digestible crude protein (DCP) intakes and the resulting growth rates of sheep (P0.05). Mean DM intake ranged from 29.1 to 53.2 g/kg W 0.75/day or from 1.1 percent to 2.1 percent of body weight (BW) in Nasiwa setaria and Boma Rhodes, respectively. Mean DM digestibility varied from 59.6 percent for Elmba to 63.4 percent for Mbarara Rhodes. DCP and ME intakes of the four Rhodes grass varieties met requirements for maintenance and growth whereas the two Setarias did not. Mean DCP and ME intake ranged from 14.2g to 37.6 g/day/kg W 0.75 and from 4.1 MJ to 9.2 MJ/day for Nasiwa Setaria and Boma Rhodes, respectively. Mean daily gain of sheep ranged from 146 g to 244.5 g/day when fed Elmba Rhodes or Boma Rhodes. The early-heading varieties were superior to their respective standard late-heading one.