Comparison of different processing methods on chemical composition, ruminal degradability and in vitro digestibility of Soybean seeds

The aim of this study was to compare different processing methods on chemical composition, ruminal degradability and in vitro digestibility of soybean seed. For this purpose, three ruminally fistulated bulls were used to measure ruminal degradability of crude protein (CP) and dry matter (DM) by nylon bag technique. Treatments were included: control, gamma irradiated soybean seeds in doses of 20 and 40 kGy, electron beam irradiated soybean seeds in doses of 20 and 40 kGy, microwave irradiated soybean seeds in 15 and 30 minutes, heated soybean seeds for 15 and 30 minutes. The results showed that gamma and electron irradiation with doses of 20 and 40 KGy and also heating for 15 and 30 minutes reduced the rapidly degradable fraction (a) of DM and CP and increased slowly degradable fraction (b) of DM and CP (P <0.05). Gamma and electron irradiation at doses of 20 and 40 KGy and heating for 15 minutes significantly reduced the effective rumen degradability of DM at rumen out flow rates of 2, 5 and 8 %/h to unprocessed treatment. (P<0.05). Gamma irradiation at doses of 20 and 40 kGy reduced the effective rumen degradability of CP at rumen outflow rates of 2 %/h compared to the non-irradiated treatment. Therefore, electron irradiation is recommended for improving nutritional value of soybeans for using in ruminant diets