Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/24/2007
Publication Date: 7/30/2007
Publication URL: http://crop.scijournals.org/cgi/reprint/47/4/1635
Citation: Norman, R.C., Coblentz, W.K., Hubbell, D.S., Ogden, R.K., Coffey, K.P., Caldwell, J.D., Rhein, R.T., West, C.P., Rosenkrans, C.F. 2007. Effects of Storage Conditions on the Forage Quality Characteristics and Ergovaline Content of Endophyte-Infected Tall Fescue Hays. Crop Science. 47:1635-1646. Interpretive Summary: Endophyte-infected tall fescue was packaged at three diameters in large-round bales at Fayetteville and Batesville AR, and then stored over winter either inside or outside on wooden pallets. After storage, bales were sampled at three depths to assess the effects of exposure on the nutritive value, in situ dry matter (DM) disappearance kinetics, and concentrations of ergovaline for these hays. The surface layer of large-round bales of tall fescue exhibited minimal deterioration when bales were packaged at relatively high densities, tied with net wrap, and elevated off the ground during extended storage. Although not compared directly, bales tied with twine and stored outside under similar conditions exhibited more retention of moisture, greater DM loss, and more negative changes in nutritive value within the surface layer. A follow-up study is needed to document storage characteristics for bales stored on the ground compared to those elevated, bales tied with net wrap compared to sisal twine, and for any possible interaction of these factors. The relatively minor changes at the surface layer for bales tied and stored outside relative to interior bale layers suggests that producers could substantially improve the quality of their stored forages with simple management techniques. Concentrations of ergovaline were not reduced within the surface layer during the 9-mo storage period; however, ergovaline was reduced substantially within all bale layers relative to concentrations at mowing. This suggests that the relative toxicity of tall fescue hay is reduced during haymaking and subsequent storage, and this may serve as an additional technique to manage the toxicity loads in tall fescue forages.
Technical Abstract: Throughout the southern Ozark Highlands, endophyte-infected tall fescue [Lolium arundinaceum (Schreb.) Darbysh] hay often is stored outdoors, without cover. At two research sites (Fayetteville and Batesville, AR), the effects of unprotected storage were assessed for large-round bales of tall fescue hay packaged at three diameters (1.1, 1.4, and 1.7 m). Bales were stored over winter either inside or outside on wooden pallets, and then sampled at three depths (0-0.15 m, 0.15-0.31 m, and 0.31-0.46 m). At both locations, bale diameter had no effect (P > 0.05) on dry matter (DM) recovery or nutritive value. Generally, there was little deterioration of nutritive value during the storage period, regardless of treatment; however, some interactions (P 0.041) of storage location and sampling depth were observed at each location. Ruminal disappearance kinetics of DM exhibited some statistical differences (P 0.030) in response to treatment; however, their relative magnitude was generally small, and there was little evidence to suggest biological relevance. After storage, concentrations of ergovaline were not affected (P > 0.05) by baling treatment at Batesville (overall mean = 256 g/kg); however, this was a 27.3% reduction from the initial concentration immediately after mowing. At Fayetteville this reduction was even greater, falling by 79.4% between standing forage (539 g/kg) and samples taken from baled hay after storage (111 g/kg). At both sites, bales stored outside on wooden pallets exhibited relatively small changes in nutritive value, disappearance kinetics, and ergovaline at the bale surface relative to the internal portions of the bale.