Effects of Electron Beam Irradiation on Dry Matter Degradation of Wheat Straw in the Rumen

Abstract

The effect of electron beam irradiation at doses of 100, 200 and 300 kGy on ruminal dry matter degradation kinetics of wheat straw was investigated. Samples were irradiated by electron beam irradiator under identical conditions of temperature and humidity. Nylon bags of untreated or irradiated wheat straw were suspended in the rumen of three Taleshi steers for up to 96 h and resulting data were fitted to non-linear degradation model to calculate degradation parameters of dry matter. Results show that the washout fractions of dry matter increased linearly (p<0.001), but potentially degradable fraction and degradation rate decreased linearly (p<0.001) by electron beam irradiation. As a consequence, the effective degradability of dry matter increased linearly (p<0.001) with increasing irradiation dose. Electron beam irradiation at doses of 100, 200 and 300 kGy increased the effective degradability of dry matter at rumen outflow rate of 0.05/h by about 7, 15 and 18%, respectively. In the condition of this study, electron beam irradiation at dose of 200 kGy appeared to be a suitable dose for improving dry matter degradability of wheat straw in the rumen.