بررسی روند تجزیه‌پذیری دانه جو و سویای پرتوتابی شده با سطوح مختلف پرتو گاما و اثر آنها در عملکرد پرواری بره‌ها

To investigate the effects of different levels of gamma irradiation on degradation rate of barley and soybean seeds and performance of lambs, this study were done. In the first experiment barley and soybean seeds were irradiated with 2 doses of gamma irradiation and degradation rate were estimated in different incubation times.  Results of current study showed that gamma irradiation increased the “a” fraction and decreased “b” fraction of barley DM, but “a” fraction of barley crude protein was decreased and “b” fraction was increased (P<0.05). Gamma irradiation on soybean seed decreased “a” fraction of crude protein and DM of soybean and increased “b” fraction of CP and DM of soybean seeds. Second experiment was conducted in completely randomized design with 3 treatments and 6 replications on Dallagh lambs. Treatments were untreated barley and soybean seeds, irradiated barley and soybean seeds with 50 and 75 KGy. Lambs were housed in individual cage about 120 days. To digestibility determination, fecal samplings were done. At the end of experiment 3 lambs from each treatment were slaughtered. Lamb carcasses and internal organs (including the liver, lungs, heart and kidneys) were also measured separately. All the data were analyses with SAS program and the means were compared with Tukey test. Statistical analysis showed that there were no significant differences between treatments and control group in feed consumption (P>0.05). Weight gain was significantly affected by irradiation treatments. Gamma irradiation with dose of 75 KGy significantly improved feed conversion ratio (P<0.05). Gamma irradiation significantly improved dry matter and organic matter digestibility of feeds (P<0.05). Internal organs were not affected by gamma irradiation (P>0.05). Regard to the results of current study, 50 KGy gamma irradiation has significant effects on by pass of protein resources and use of starch in the diets. Thus, we can use irradiation to get the better performance in ruminant nutrition.