Keeping in view the objectives of the study, PRA was conducted in experimental areas. Four villages in Mymensingh District were selected purposively. Among 4 villages Rajpur and Garaikuti are in Muktagachha Thana, and Mothbari and Bhoradoba are in Trishal Thana. The government officials of respective Thana offices helped in selecting these areas. The experimental period lasts from January to October, 2001.
Climatic condition of the experimental sites: The climatic condition of the experimental sites is characterized by light rainfall during April- May and heavy rainfall during June- September. The soil is silt loamy to silty clay loamy and gray brown to dark gray.
Construction of improved storage: Eight improved stores were constructed, four in each site. Out of four, two stores were built in each village, one for small farmers and the other for medium farmers. The improved storehouses were gable-type tin shed with raised slate about 1 / ft height from the ground. The size of the 1 2 storage was length- 22.5 ft., height- 9ft., and width- 13ft.
Sampling of rice straw: After construction, same rice straw was stored in both improved and traditional stores so that the comparison of the effectiveness of storage technique could be made irrespective of farm size, in regard to nutritive value, in vitro digestibility, metabolizable energy content and mycotoxin level in the rice straw. Rice straw was randomly sampled from both improved and traditional stores in two occasions. Ten straw samples of 1 kg was randomly collected from different locations of improved and traditional storage. Straw samples were kept in a polyethylene bag and was labeled properly for future use.
Preparation of straw sample : After collection from the stack, straw was chopped to 3-4 cm size with the help of sickle. After that the chopped straw was exposed to sun drying in order to facilitate grinding. Then the chopped straw was ground to 2-3 mm size for chemical analyses. After grinding each 10 kg straw from one stack, it was mixed properly, piled, flattened and quartered until it was reduced to 2.5 kg. Then 0.5 kg was kept for proximate analysis and in vitro digestibility and 2.0 kg of mixed sample was sent to Natural Resources Institute (NRI), UK. for analysis of mycotoxins. For In vitro study the ground sample was again oven-dried and ground to 1.0mm mesh size with the help of a micro grinder.
Chemical Analyses of rice straw: The chemical analyses was done at the Bangladesh Agricultural University, Animal Nutrition Laboratory following the methods of AOAC (1990). Straw sample was analyzed for dry matter (DM), crude protein (CP), crude fiber (CF), ash, ether extract (EE) and nitrogen free extract (NFE).
Fumonisin: The NRI standard operating procedure for Fumonisin analysis, MT_SOP209, with immuno-affinity clean-up (VICAM Fumonitest), quantification by high-performance liquid chromatography using a Spherisorb ODSI reverse phase column, pre-column derivatization with o-phthaldialdehyde, fluorescence detection using 335 nm excitation and 440 nm emission wavelengths has been used.
Aflatoxins: The NRI standard operating procedure for Aflatoxin analysis, MT_SOP, (Bradburn et al., 1990) with quantification by high-performance liquid chromatography using a Spherisorb ODSI reverse phase column, post-column derivatization by means of a KOBRA electrochemical cell and fluorescent detection at 360 nm excitation and 440 nm emission wavelengths has been used. Extraction is performed by adding acetone: water (80:20) and shaking for 45 minutes and the clean-up uses a phenyl-bonded SPE column (Varian).