نوع مقاله : مقاله پژوهشی
نویسندگان
1 استادیار گروه علوم دامی، دانشگاه آزاد اسلامی، واحد قائمشهر.
2 دانشیار، پژوهشکده کشاورزی هسته ای، پژوهشگاه علوم و فنون هسته ای سازمان انرژی اتمی ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and objectives: Fiber materials often have little digestibility due to the presence of cell wall compounds (cellulose, hemicellulose and lignin) and this problem is the reason for longer shelf life of edible materials in the rumen, reducing feed consumption, reducing digestibility and reducing production in ruminants. For this reason, studies have sought to find a way to increase the digestibility and decomposability of fiber materials in the rumen. In various studies, it has been proven to improve the parameters of degradability and increase the attachment of bacteria to fiber particles of materials due to the use of electron beam methods. Conducting this research, a new horizon of the application of this industry in animal nutrition study, and can be a starting point for further study in this field. Therefore, the aim of this study was to investigate the effect of different levels of electron irradiation on the parameters of degradability of insoluble fibers in acid detergent, particle size distribution and relative abundance of fibrolytic bacteria in wheat straw, barley straw and sugarcane bagasse fibers.
Materials and methods: To perform this study, 3 fistulad Shall breed sheep with an mean weight of about 59 kg and an mean age of about 12 months were used to determine the parameters of decomposition. The sheep were housed in a covered and semi-open place, inside a metabolic cage with a ration slightly more than the maintenance level. Electron irradiation was performed on food items at Yazd radiation center with doses of 250 and 500 kgy. Irradiation was carried out using a TT 200 model electron accelerator with a constant energy of 10 megaelectron volts and with a maximum error of 10%.
For this purpose, 3 sheep equipped with rumen fistula were used. To observe the condition of the cell wall of wooden materials, the LEO44Oi model electron microscope made in England was used. For this purpose, each food sample was photographed with three different doses (0, 250 and 500 kg) and with X800 magnification.
Results: The results of the effect of electron radiation on the parameters of the degradability of ADF of wheat straw, barley straw and sugarcane bagasse showed that there is a significant difference between the experimental treatments in the sections of rapidly degraded fraction, slowly degraded fraction, constant rate of degradation and effective degradability with different passage rate (P<0.05). Irradiation in wheat straw and barley straw at the levels of 250 and 500 kGy compared to the control group caused a significant increase in degradability parameters. Also, irradiation in sugarcane bagasse at the level of 500 kgy compared to other treatments caused a significant increase in degradability parameters in slowly degraded fraction and effective degradability with different passage rate. The results of the effect of electron irradiation on the relative frequency of ruminal fluid fibrolytic bacteria showed that there is a significant difference in the relative frequency of Ruminococcus flavofcins and Fibrobacter succinogenes between experimental treatments (P<0.05). By increasing the radiation level up to 500 kGy, an increase in the relative frequency of Ruminococcus flavofcins and Fibrobacter succinogenes bacteria was observed in some repetitions of the experiment, which was significantly higher than the control group. Scanning electron microscope images with different doses showed that by increasing the level of radiation up to 500 kGy, a significant increase in the creation of holes and surface fractures of the fibers was observed (P<0.05).
Conclusion: The general result of the current study showed that radiation at 500 kGy levels caused a significant increase in the parameters of degradability of ADF, relative abundance of Ruminococcus flavofcins and Fibrobacter succinogenes bacteria,
کلیدواژهها [English]
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