Effect of electron-beam irradiation on nutritional value of Atriplex stem

In this study, atriplex stem samples were irradiated with three doses (100, 200 and 300 KGy) to evaluate the effect of electron beam on the chemical composition, ruminal degradability parameters and ruminal-postruminal digestibility of dry matter (DM) and neutral detergent fiber (NDF). Initially, using nylon bag technique, an amount of 5 g of grounded sample (six replicates) was incubated for 0, 2, 4, 8, 16, 24, 48 and 72 hours in the rumen of two Holstein heifers and then parameters of ruminal degradability were estimated. Then ruminal digestibility and post ruminal digestibility of nutrients were determined by incubating of samples in rumen for 16 h and by Daisy digester apparatus, respectively. Statistical analysis was performed using SAS software. The results indicated that reduction of acid detergent fiber (ADF) in irradiated samples was numerically reduced, while NDF reduction was statistically significant (P<0.05). Quickly degradable fraction (a), potentially degradable fraction (b) and effective degradability of DM increased significantly (P<0.05) with increasing dose of irradiation. Quickly degradable fraction (a) of NDF at the doses of 100 and 200 KGy irradiation increased but this change was not statistically significant. Potentially degradable fraction (b) of NDF was significantly increased (P<0.01). Quickly degradable fraction (a) of ADF at the dose of 300 KGy increased that it was not statistically significant. Post-ruminal and total tract digestibility of DM increased significantly (P<0.05). Ruminal, post ruminal and total tract digestibility of NDF was not affected by irradiation. This experiment showed electron beam irradiation had an effective role in improving the nutritive value and digestibility of atriplex stem, but regarding the absence of a dose related effect, the dose of 100 KGy is recommended.