ARS | Publication request: Eastern Gamagrass Management for Pastures in the Mid-Atlantic Region: I. Animal Performance and Pasture Productivity

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 10, 2009
Publication Date: January 25, 2010
Citation: Burns, J.C., Fisher, D.S. 2010. Eastern Gamagrass Management for Pastures in the Mid-Atlantic Region: I. Animal Performance and Pasture Productivity. Agronomy Journal. 102:171-178

Interpretive Summary: Eastern gamagrass can be readily established in 15-cm rows with a desirable plant density and cover suitable for pasture. Steers readily consumed EG whether stocked continuously or rotationally. If continuously stocked, a pasture canopy height of 36 to 46 cm resulted in greatest steer gains (0.90 kg d-1) and carried 6.1 steers ha-1 producing 735 kg ha-1 of weight gain. Increasing the canopy height > 51 cm was not beneficial. Rotational stocking, regardless of using two or 10 subdivisions, did not alter steer gains which averaged 0.67 kg d-1 and carried 6.8 steers ha-1 producing 612 kg ha-1 of weight gain. In contrast, continuous stocking of the Coastal bermudagrass control resulted in less gain per steer (0.57 kg d-1) and carried more steers ha-1 (10.0) but produced similar weight gain ha-1 (692 kg ha-1). The survival of well managed EG pasture and the favorable daily performance of grazing steers indicates the EG can contribute to animal production systems in the Mid-Atlantic Region. The role of EG appears to be as a special purpose warm-season perennial grass pasture when greater daily animal performance is the objective, as opposed to simply maintaining the brood-cow herd.

Technical Abstract: Eastern gamagrass [Tripsacum dactyloides (L.) L.] is a native, warm-season perennial grass with potential as pasture for the eastern USA, but its value has not been well studied. The objective of this 4-yr experiment was to estimate forage mass (FM) for eastern gamagrass (EG) that maximizes steer 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 10-14 d interval (FM = 1348 kg ha-1) and10-subdivisions with steers moved every 3-4 d with a 27-36 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.