ARS | Publication request: EFFECTS OF SIMULATED RAINFALL ON NITROGEN PARTITIONING AND RUMEN DEGRADABLE PROTEIN IN WILTING ORCHARDGRASS FORAGES

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract
Publication Acceptance Date: November 4, 2004
Publication Date: November 4, 2004
Citation: Coblentz, W.K., Scarbrough, D.A., Ogden, R.K., Turner, J.E., Humphry, J.B., Coffey, K.P., Daniel, T.C., Sauer, T.J., Jennings, J.A., Kellogg, D.W. 2004. Effects of Simulated Rainfall on Nitrogen Partitioning and Rumen Degradable Protein in Wilting Orchardgrass Forages [CD-ROM]. ASA-CSSA-SSSA Annual Meeting Abstracts. Madison, Wisconsin.

Technical Abstract: A study was conducted to investigate the effects of simulated rainfall on rumen degradable protein for wilting orchardgrass (Dactylis glomerata L.; OG) hays. Rainfall was applied with a rainfall simulator at a constant rate of 76 mm/h in graded amounts totaling 0, 12, 25, 38, 51, 64, or 76 mm. Wilting OG forage was desiccated to 674, 153, or 41 g/kg of moisture in the field prior to applying the simulated rainfall and was allowed to air dry on top of grass stubble or were oven-dried under forced air at 50°C. For OG receiving simulated rainfall immediately after mowing (674 g/kg moisture), CP increased linearly (P = 0.003) with simulated rainfall. Degradable intake protein exhibited an interaction (P = 0.013) of rainfall amount x drying method with oven-dried estimates being greater generally than those that were air dried. For OG wilted to 153 g/kg moisture, CP increased quadratically (P = 0.040) with rainfall amount, while neutral detergent insoluble N (NDIN) increased with linear (P = 0.0001), quadratic (P = 0.0003), cubic (P = 0.023), and quartic (P = 0.008) effects. In contrast, degradable intake protein decreased linearly (P = 0.0001) with simulated rainfall from 65.6 to 60.9% of CP. For very dry OG (41 g/kg of moisture), degradable intake protein decreased in linear (P = 0.029) and quadratic (P = 0.009) patterns from 66.5 to 62.3% of CP.