Effect of Microwave Treatment on Chemical Composition and In sacco Digestibility of Wheat Straw in Yak Cow

Wheat straw was treated with microwave for 4 min and 8 min at a power of 750 W and frequency of 2,450 MHz. Chemical compositions of untreated, 4 min treated and 8 min treated straws were analyzed and in sacco degradabilities of all these straws in yak rumens were measured. Microwave treatment didn't significantly (p>0.05) affect the chemical composition of the straw. In sacco dry matter (DM) degradability of the straw after 18 h incubation in rumen was significantly (p<0.01) improved by microwave treatment. In sacco crude protein (CP) degradability of the straw was not (p>0.05) affected by microwave treatment. In sacco organic matter (OM) degradability of the straw was increased (p<0.01) by around 20% for both the 4 min and 8 min microwave treatment, that of acid detergent fibre (ADF) was increased (p<0.01) by 61.6% and 62.8%, and that of ash free ADF was enhanced by 72.1% and 69.6% for the 4 min and 8 min microwave treatment respectively. No significant difference was observed between the 4 min and 8 min microwave treatment on the degradability of DM, OM, CP, ADF and ash-free ADF of the straw.