Abstract 444

Addison,-KB; Cameron,-DG; Blight,-GW

Queensland Dep. of Primary Industries, Brian Pastures Res. Sta., Gayndah, Qld. 4625, Australia.

Tropical-Grasslands. 1984, 18: 3, 113-120; 24 ref.

Hereford steers grazing native speargrass pasture with dominant Bothriochloa bladhii were fed 680 g cottonseed meal, 318 g cottonseed meal + 318 g sorghum meal + 44 g biuret or 597 g sorghum meal + 83 g biuret/head day, providing supplements of equal N content, during May-Nov. 1969 and March-May 1970. Between Nov. and March all animals grazed unsupplemented green panic pastures. Cottonseed meal was the superior supplement during both periods, with liveweight gains of 60.9 and 29.2 kg/head, resp., compared with 10.5 and 14.5 kg/head, resp., for unsupplemented animals. Sorghum meal plus biuret produced liveweight gains of 29.8 and 19.6 kg/head, resp., over the 2 seasons. Sorghum meal plus biuret was not an effective substitute for half the N in cottonseed meal, and produced gains of 37.5 and 26.4 kg/head when fed with cottonseed meal. In a second trial, weaner steers receiving supplements balanced for energy content were fed 680 g cottonseed meal, 650 g sorghum meal or 650 g sorghum meal + 113 g biuret. Cottonseed meal remained the most effective supplement with liveweight gain of 18 kg compared with -10.0 kg/head for sorghum meal, -1.4 kg for sorghum meal + biuret and -16.5 for no supplement.