Effects of processing with electron beam, hydrogen peroxide and hydrobromic acid on the nutritional value of vetch wastes

Introduction Recently, considering the fact that access to high quality feed stuffs is limited, using agricultural by-products in animal nutrition has taken to consideration. Effective use of these products as alternative energy source for ruminant feeding is important for economical and environmental reasons. Major limitation for using agricultural by-products as ruminant feed stuffs is their low digestibility because of cellulose crystallinity and close physical association between structural carbohydrates and lignin. Physical (soaking, milling and steaming), chemical (alkaline, acidic and oxidative agents), and biological (enzymes, white rot fungi and mushroom) processing methods have been used extensively to break down lignocellulose structure of crop residues. Irradiation is another physical processing because of its effectiveness without any side effects on environment. The concept of feedstuff irradiation refers to using ionizing radiations of gamma ray (GR) or electron beam (EB). The purpose of the present study was to determine the effects of EB, hydrobromic acid (HBr) and hydrogen peroxide (H2O2) on the chemical composition and ruminal degradability of vetch wastes. Materials and method Vetch wastes were prepared from Fars province farms. For the EB processing, samples were subjected to 10 MeV EB of Rhodotron accelerator to doses of 150 and 200 kGy. Irradiated and unirradiated samples were sprayed with HBr and H2O2. 60 ml HBr diluted in 250 ml distilled water /kg of dry matter (DM). In order to processing with H2O2, first the samples pretreated with sodium hydroxide (NaOH, 80 g/kg DM) to attain and maintain a pH of 11.5, then 132 ml H2O2 (purity: 35%) were added. Treated samples were then placed into plastic bags, tied up and stored under anaerobic conditions for 18 days. Then the bags were opened and samples dried by exposure to air. Chemical composition of the samples was determined using the standard methods. Ruminal degradability trial was carried out by the nylon bag technique. Crystallinity degree of the samples was investigated through X-ray diffraction (XRD) technique. The resulting data of the study were analyzed by the SAS software.
Results and Discussion Processing was effective on the chemical composition of the vetch wastes (P