Eastern gamagrass management for pasture in the Mid-Atlantic region: i. animal performance and pasture productivity
Eastern gamagrass [Tripsacum dactyloides (L.) L.] (EG) is a native, warm-season perennial grass with potential as pasture for the eastern United States, but its value has not been well studied. The objective of this 4-yr experiment was to estimate forage mass (FM) for EG that maximizes steer (Bos taurus) performance and pasture productivity. Five treatments (three continuously and two rotationally stocked) were compared with a continuously stocked ‘Coastal’ bermudagrass [Cynodon dactylon (L.) Pers.] control. The three continuously stocked treatments had mean FM (10-cm stubble) levels of 559 kg ha–1 (Short), 1103 kg ha–1 (Medium), and 1932 kg ha–1 (Tall). Rotational treatments consisted of two subdivisions with steers moved on a 10 to 14 d interval (FM = 1348 kg ha–1) and10 subdivisions with steers moved every 3 to 4 d with a 27 to 36 d regrowth interval (FM = 2061 kg ha–1). The average daily gain (ADG) from the Medium continuously stocked treatment was greatest at 0.90 kg (P = 0.02) and produced similar annual gain per hectare (735 vs. 749 kg ha–1; P = 0.08) as Short. Rotational pastures had greater FM than continuously stocked (1705 vs. 1198 kg ha–1; P = 0.03), but the least ADG (0.67 vs. 0.79 kg; P = < 0.01). Bermudagrass produced less ADG than EG (0.57 vs. 0.79 kg; P < 0.01), but gain per hectare was similar (662 kg ha–1) and stocking rate was greater (10.0 vs. 6.7 head ha–1; P < 0.01). Eastern gamagrass has potential as a special purpose pasture for the region when greater ADG is the goal.