J. Bio. & Env. Sci. 2014 349 | Paya et al RESEARCH PAPER OPEN ACCESS Effects of microwave irradiation on in vitro ruminal fermentation and ruminal and post-ruminal disappearance of safflower seed Hamid Paya * , Akbar Taghizadeh, Hossein Janmohammadi, Gholam Ali Moghaddam, Ali Hossein Khani, Sadegh Alijani Department of Animal Science, Faculty of Agriculture, University of Tabriz, Iran Article published on August 11, 2014 Key words: Microwave irradiation, Rumen fermentation, Safflower seed, Gas production, ruminal and post- ruminal disappearance Abstract Effects of microwave irradiation (900 W) for 3 min on fermentation kinetics and ruminal, post-ruminal and total tract dry matter (DM) and crude protein (CP) disappearance of safflower seed were evaluated by in vitro gas production, modified three-step method and in vitro disappearance method. Cumulative gas production was recorded at 2, 4, 6, 8, 12, 16, 24, 36, 48, 72 and 96 h of incubation and its kinetic was estimated using model: GP = A (1 − e −ct ). The rumen undegradable protein fractions of the raw and microwave treated safflower seed were obtained by ruminal incubation in two cannulated wethers and incubation in protease solution (protease type xiv, streptomyces griseus). The data were analysed using completely randomized design. Results indicate that microwave processing increased cumulative gas production (p<0.05). Disappearance of DM and CP were significantly decreased (P<0.05) compared with untreated safflower seed as microwave irradiation. Also, microwave irradiation significantly reduced (P<0.05) post-ruminal disappearance of DM and CP. According to the results, microwave irradiation can be used for feed processing and reduced feed nutrient availability. Also, these processing methods appear to shift the site of CP digestion from the rumen to the small intestine and increase the amount of CP digested in the small intestine. * Corresponding Author: Hamid Paya  hamid.paya@tabrizu.ac.ir Journal of Biodiversity and Environmental Sciences (JBES) ISSN: 2220-6663 (Print) 2222-3045 (Online) Vol. 5, No. 2, p. 349-356, 2014 http://www.innspub.net