Effects of Electron Beam Irradiation on Ruminal NDF and ADF Degradation Characteristics of Barley Straw

摘要

Samples of barley straw were irradiated with various doses of electron beam (100, 200 and 300 kGy) to evaluate the effects of electron beam irradiation on Neutral Detergent Fiber (NDF) and Acid Detergent Fiber (ADF) degradation. Nylon bags of untreated or irradiated barley straw were suspended in the rumen of three Taleshi bulls for up to 962 h and resulting data were fitted to non-linear degradation model to calculate degradation parameters of NDF and ADF. Results showed that the washout fractions (a) and the potentially degradable fraction (b) of NDF and ADF of barley straw increased linearly (p<0.001) as irradiation dose increased. The degradation rate of the b fraction of NDF of barley straw decreased as irradiation dose increased (linear effect, p<0.001), but this fraction in ADF of samples was the highest at dose of 100 kGy. Effective degradability of NDF and ADF of samples 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 NDF and ADF at rumen outflow rate of 0.05 h 1 by about 3, 4 and 5% for NDF and 3, 6 and 8% for ADF, respectively. In the condition of this study, electron beam irradiation at dose of 200 kGy appeared to be a suitable dose for improving NDF and ADF degradability of barley straw in the rumen.