Abstract 114

Sollenberger,-LE; Jones,-CS, Jr.

Department of Agronomy, University of Florida, Gainesville, FL 32611, USA.

Tropical-Grasslands. 1989, 23: 3, 129-134; 15 ref.

In an experiment in 1984-86 on a site 20 km NE of Gainesville, beef production was compared on established dwarf Pennisetum purpureum cv. Mott and Paspalum notatum cv. Pensacola pastures given N fertilizer each year. Av. daily liveweight gain (ADG) over the 3 seasons was 0.97 kg for Mott and 0.38 kg for Pensacola. Av. stocking rate on both grasses was approx. 4 yearling steers/ha, and total beef production/ha averaged 483 kg for Mott and 318 kg for Pensacola. Differences in ADG between grasses was primarily due to higher digestibility and protein in Mott herbage than in Pensacola. Differences in ADG and nutritive value between grasses were particularly pronounced during the late summer to early autumn period, a time when ADG on Pensacola was very low. Estimated annual DM accumulation on Mott and Pensacola pastures averaged 8.2 and 7.1 t/ha, resp., over the 3 years. Mott persisted well under good grazing management but its principal limitation was the need to propagate it vegetatively.