2009 Annual Report
1a.Objectives (from AD-416)
Identify and characterize alternative management strategies in the humid Southeast for integrating gamagrass and switchgrass into traditional pasture and livestock production systems by evaluating interactions between forage management options, plant performance and animal performance, and increased agronomic knowledge for producing biomass crops.
1b.Approach (from AD-416)
This project will be conducted jointly between USDA-ARS and the North Carolina Agricultural Research Service representing a true cooperative program (Burns, 2006). In this program the state of North Carolina contributes experimental animals and major field, animal, and laboratory facilities and technical assistance as well as routine maintenance needs for all facilities to meet the objectives of the research and the contributions from both will be detailed below.
Process – Two grazing trials were summarizes for publication during FY 2009:
One trial (4 years) compared the animal and pasture productivity of eastern gamagrass when stocked over a range of herbage mass levels (3) to determine the optimum and two rotational managements all compared with Coastal bermudagrass stocked at its optimum herbage mass.
The second trial (4 years) evaluated per animal and per ha productivity of Caucasian bluestem when stocked over a range of three herbage mass levels to determine the optimum herbage mass.
Eastern gamagrass was readily established in 15 cm rows. When continuously stocked (mean = 6.1 steers/ha) at a mean herbage mass of 1100 kg/ha (13- cm stubble) steers gained 0.90 kg/day with pasture producing 735 kg/ha of steer gain. This compares with gains of 0.57 kg/day from Coastal bermudagrass when stocked with 10.0 steers/ha and pastures produced 662 kg/ha of steer gain. Gamagrass appears well adapted to the upper south.
Caucasian bluestem was readily established and pastures were effectively utilized by grazing steers. Continuous stocking at 9.7 steers/ha to maintain the herbage mass at 1400 kg/ha (2.5-cm stubble) resulted in steer gains of 0.77 kg/day which was similar regardless of herbage mass used (1400 – 2750 kg/ha and mean daily gain = 0.76 kg). The greater stocking rate used, or shortest canopy height maintained, resulted in greatest pasture productivity averaging 817 kg/ha of steer gain and produced a dense pasture mat with greatest ground cover (70 %).
Process – A series of intake and digestion trials comparing improved perennial cool-season grass hays from different environments at different maturities were summarized for publication during FY 2009:
MaxQ, HM4 and Cajun tall fescues were compared with Persist Orchardgrass. Goats consumed MaxQ and HM4 similar to Persist (mean = 2.49% of body weight) and Cajun least (1.62 % body weight), but digested MaxQ and Cajun similarly (61.7 %) and greater than Persist (58.2 %). Steers consumed the most of Persist (2.40 % of body weight) compared with MaxQ (2.14 % of body weight) and HM4 (1.98 % of body weight) but digested MaxQ greater (62.6 %) than either HM4 (58.5%) or Persist (59.7 %). Considering digestible dry matter intake either MaxQ tall fescue or Persist orchardgrass would provide forage of similar quality in both goat and steer enterprises.
Plant - Animal Interface Trials:
A plant-animal interface trial evaluating the use of temperate legumes (alfalfa and white clover) as a source of nitrogen for switchgrass when grown as a riparian buffer is being summarized. The area was defoliated by grazing animals to assess the potential contribution of switchgrass riparian zones to a production system.
Switchgrass was readily grazed but white clover continues to appear to be too aggressive to maintain switchgrass stands.
Gamagrass: It’s potential in production systems for the humid Southeast. Research was conducted to determine if gamagrass was sufficiently pliable to be used as pasture, hay and silage, as well as biomass, in the Mid-Atlantic Region. Gamagrass was grazed to obtain an estimate of steer daily performance and potential pasture production and cut and preserved as both hay and silage to determine its nutritive value and quality. Gamagrass, a possible candidate for cellulosic production for bio-fuel, is sufficiently pliable to be an integral part of ruminant production systems in the Mid–Atlantic Region.
Burns, J.C. 2008. Utilization of Pasture and Forages by Ruminants: A Historical Perspective. Journal of Animal Science. 86:3647-3663.
Burns, J.C., Fisher, D.S., Wagger, M.G. 2009. Animal and Pasture Production of 'Coastal'and 'Tifton 44' bermudagrass at three nitrogen rates. Agronomy Journal. 101:32-40.
Cantrell, K.B., Stone, K.C., Hunt, P.G., Ro, K.S., Vanotti, M.B., Burns, J.C. 2009. Bioenergy from Coastal bermudagrass receiving subsurface drip irrigation with advance-treated swine wastewater. Bioresource Technology 100:3285-3292.
Sauve, A.K., Huntington, G.B., Burns, J.C. 2008. The Effect of Total-Nonstructural Carbohydrates and Nitrogen Balance on Voluntary Intake of Goats and Digestibility on Gamagrass Hay Harvested at Sunrise and Sunset. Animal Feed Science And Technology. 148:93-106.
Burns, J.C., Fisher, D.S. 2008. Coastal and tifton 44' bermudagrass availability on animal and pasture productivity. Agronomy Journal. 100:1280-1288.
Vibart, R.E., Fellner, V., Burns, J.C., Green, J.C. 2008. Performance of Lactating Dairy Cows Fed Varying Levels of Total Mixed Ration and Pasture. Journal of Dairy Research. 75:471-480.
Fisher, D.S., Burns, J.C. 2008. Testing for variation in animal preference for Jesup tall fescue hays with wild-type, novel, or no fungal endophyte. Crop Science. 48:2026-2032.
Burns, J.C., Stone, K.C., Hunt, P.G., Vanotti, M.B., Cantrell, K.B., Fisher, D.S. 2009. Intake and digestibility of ‘Coastal’ bermudagrass hay from treated swine waste using subsurface drip irrigation. Journal of Environmental Quality. 38:1749-1756.
Huntington, G. B., Magee, K., Matthews, A., Poore, M., & Burns, J. (2009). Urea metabolism in beef steers fed tall fescue, orchardgrass, or gamagrass hays. Journal of Animal Science. 87:1346-1353.