Mohsen Hajipour, Ali Nikkhah, Parvin Shawrang, Mohamad Chamani
Department of Animal Science, Science and Research Branch, Islamic Azad University, Tehran, Iran
Nuclear Agriculture Research School, Nuclear Science and Technology Research Institute, Atomic Energy Organization of Iran, Karaj, Iran
Key words: Electron beam irradiation, neutral detergent fiber, digestibility, Sugarcane bagasse.
The purpose of this study was to evaluate the effects of electron beam irradiation on fiber morphology and ruminal fiber degradability of sugarcane bagasse. Samples of untreated or electron beam irradiated sugarcane bagasse were subjected to the rumen of three fistulated rams and ruminal degradation parameters of neutral detergent fiber were determined. The association of rumen bacteria with tissues of the sugarcane bagasse during ruminal degradation was investigated by scanning electron microscopy. Based on the results, electron beam irradiation increased the water soluble fraction, degradable fraction, degradation rate and ruminal effective degradability of neutral detergent fiber as dosage increased (P < 0.05). In untreated bagasse, there was a natural structure of fiber in the surface with large particle size, multiple layers, small pores and cavities. Irradiation at doses of 250 and 500 kGy resulted in the breakdown of the fiber, drastically reduction in particle size of the fibers and smooth edge. The electron beam irradiation increase or deepen the cleavages. Scanning electron microscopy images showed that at dose of 500 kGy, there was a higher activity of fibrolytic bacteria on the surface of fibers. In this irradiation dose, the penetration of microorganisms and also layer separation was higher than dose of 250 kGy. In addition small particles were not observed on the surface, but irregular fractures and folds observed. The data suggest that electron beam irradiation at dose of 500 kGy could change fiber morphology and improve ruminal fiber degradability of sugarcane bagasse.