نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی دکتری، گروه علوم دامی دانشگاه آزاد اسلامی واحد شهر قدس.
2 استادیار، گروه علوم دامی دانشگاه آزاد اسلامی واحد شهر قدس،
3 دانشیار، گروه علوم دامی دانشگاه آزاد اسلامی واحد شهر قدس.
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Background and objective: Imbalance of between rumen degradable protein (RDP) and microbial protein (MP) production decrease animal performance and increase environmental pollution. Therefore to meet the requirements for microbial protein without excessive N, rations must also be balanced for RUP and RDP. Sunflower meal (SFM) is a protein feedstuff for ruminants. However, its use in ruminant nutrition is often limited by high protein degradability in the rumen. Irradiation is new method that is considered in protein feedstuffs processing. The aim of this study was to investigate the effect of irradiation on rumen degradation kinetics and in vitro digestibility of SFM.
Materials and Methods: SFM samples were irradiated with the use of the gamma ray (GR) in doses of 20 and 40 KGy and microwave (MV) at 800 W for 3 and 5 minutes. Irradiations of samples were done in Radiation Applications Research School, Nuclear Science and Technology Research Institute. Chemical composition of unirradiated and irradiated SFM were determined. Degradability parameters of the samples were measured by nylon bag technique using three rumen fistulated Dashtyari cattle for 0, 2, 4, 8, 16, 24 and 48 hours. The two-step digestion technique was used to determine digestibility of SFM. Statistical analysis of data was performed using SAS software.
Results: GR irradiation decreased DM of SFM. Irradiation of SFM caused a reduction in EE, NDF, ADF and Ash and increased CP compared to unirradiated SFM. GR irradiation decreased wash out fraction degradation, rate constant of degradation of b fraction and ERD and increased potentially degradable fraction of SFM. MV irradiation for 5 minutes increased washout fraction of CP and decreased potentially degradable fraction (P<0.05). Treatment of SFM by MV for 5 minutes caused a reduction in potential degradability of CP (P<0.01). Processing of SFM with MV for 3 minutes decreased ERD of CP at rumen outflow rate of 0.02h-1(P<0.05). GR irradiation decreased RDP and increased RUP and metabolizable protein (MP) (P<0.01). Irradiation of SFM with GR increased ERD of CP at rumen outflow rate of 0.05h-1 and 0.08h-1 (P<0.01). Irradiation of SFM with MV increased RDP(P<0.01) and increased ERD and MP at rumen outflow rate of 0.02h-1 (P<0.01). MV irradiation for 3 minutes at rumen outflow rate of 0.02h-1and 0.05h-1increased RUP(P<0.05). The coefficient of crude protein convert in to RDP and RUP in GR- irradiated SFM was decreased and increased respectively (P<0.01). MV irradiation for 3 minutes at rumen outflow rate of 0.02h-1 coefficient of crude protein convert in to RDP and RUP decreased and increased respectively (P<0.05). In vitro digestibility of SFM was unaffected by irradiation (P>0.05).
Conclusion: The experiment results indicated that, irradiation of SFM with GR had better effect on increasing of RUP and improving of quality of SFM.
کلیدواژهها [English]