Evaluation of Soft Red Winter Wheat Forage Yield, Nutritive Value and Tetany Hazard as Influenced by Sampling Date and Nitrogen Fertilization

Abstract

Bailey, C.R., Daniels, L.B., Coblentz, W.K., Kegley, E.B., McBeth, L.J., Turner, J.E., Wistuba, T.J. and Rosenkrans Jr., C.F. 2007. Evaluation of soft red winter wheat forage yield, nutritive value and tetany hazard as influenced by sampling date and nitrogen fertilization. J. Appl. Anim. Res., 32: 1–6. A study was conducted from December through March using a completely randomized design to evaluate yield, nutritive value and tetany hazard of soft red winter wheat (Triticum aestivum L.) forage as influenced by nitrogen (N) fertilization rate and date of sampling. Dry matter (DM) yield, forage DM, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), in vitro, dry matter disappearance (IVDMD), organic matter (OM), calcium (Ca), magnesium (Mg) and potassium (K) were evaluated. Nitrogen fertilization had no effect (P>0.05) on forage yield, OM, ADF, NDF, IVDMD, Ca or Mg. Forage DM (P<0.01) decreased while CP (P<0.01) andK(P<0.05) increased linearly with increasing levels of N fertilization. Date of sampling exhibited linear, quadratic, cubic and quartic effects (P≤0.01) on concentrations of forage CP, DM, PVDMD, ADF, NDF and K. With respect to sampling date, linear (P<0.01) and quadratic (P=0.01) effects were observed for DM yield, but only linear effects were noted for OM (P<0.01). Calcium responded to sampling date with linear and cubic (P<0.01) patterns, while Mg exhibited linear (P<0.01), quadratic (P<0.01), and cubic (P=0.02) effects. No N × sampling date interactions were observed. Increasing levels of N enhanced concentrations of CP and decreased DM content, but had no effect on yield or other forage quality parameters. However, sampling date affected forage quality by decreasing concentrations of CP and IVDMD, while increasing concentrations of ADF and NDF.