Steer Performance from Two Perennial Pennisetum Species, Switchgrass, and a Fescue—‘Coastal’ Bermudagrass System1
- J. C. Burns,
- R. D. Mochrie and
- D. H. Timothy2
Subtropical perennial grasses make important contributions to productive, season-long grazing systems in the USA. The perennial bermudagrasses, particularly ‘Coastal’ bermudagrass [Cynodon dactylon (L.) Pers.], are extremely productive, but high fiber allows only poor to moderate animal performance. Steer average daily gains (ADG) and productivity estimates of the subtropical perennials flaccidgrass (Pennisetum flaccidurn Griseb.), P. orientale Rich., and switchgrass (Panicum virgatum L.) were obtained. Sequential grazing of tall fescue (Festuca arundinacea Schreb.) and Coastal as a system (F + C) served as the standard for comparison. The grazing experiment with yearling steers was conducted on a Typic Hapludult soil for 3 years. Calendar days grazed, ADG (kg) and steers ha−1, respectively, from initiation of grazing until Coastal was stocked (period 1) averaged 53, 0.93, and 15.1 for tall fescue; 20, 1.35 and 11.1 for flaccidgrass and 40,1.07, and 8.9 for switchgrass. Number of steers ha−1 was greatest on tall fescue and ADG lowest (P ≤ 0.06). Flaccidgrass supported significantly more animals than switchgrass. Summer (period 2) results (avg. 98 days) for AM; and steers ha−1, respectively, were 0.43 and 25.1 for Coastal; 0.78 and 9.1 for flaccidgrass (P. orientale was similar), and 0.92 and 7.9 for switchgrass. Steer ADG was lowest and steers ha−1 highest on Coastal, while the other grasses were similar for both. Tall fescue made little contribution because rainfall was below normal all 3 years. Seasonal results from the F + C showed most calendar days (160), lowest ADG (0.59) but similar numbers of steers ha−1 (9.5) compared with respective values of 130,0.90, and 9.6 for flaccidgrass and 140, 0.96 and 8.2 for switchgrass. Flaccidgrass averaged significantly more steers ha−1 than switchgrass. Gain ha−1 from tall fescue in period 1 (792 kg) and Coastal in period 2 (1160 kg) was greater than the average for the other grasses, 349 and 559 kg, respectively. However, seasonal computations based on combined land areas for the F + C system yielded 1010 kg of gain ha−1. That gain did not differ from the 930 kg ha−1 for the other grasses, even though the F + C system averaged 25 more calendar days. Flaccidgrass and switchgrass have quality attributes and a sufficiently long growing season to make an important contribution to an animal enterprise that values large daily animal responses. Coastal is more appropriately used in enterprises for an animal class, or portion of the season, where only moderate to low response animal−1 is required.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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