Fazaeli et al., 2006. Asian-Aust. J. Anim. Sci., 19 (6): 845-851

Spent compost wheat straw is an available byproduct from edible mushroom production, which constitutes a potential pollutant and is cost effective for disposal. This study was conducted to determine the nutritive value of spent wheat straw compost from Agaricus bisporus mushroom production as ruminant feed. The compost was provided from a mushroom farm. The casing soil was removed from the whole compost, sun-dried and sampled for chemical analysis. An experiment was conducted, in which 4 wheat straw-based diets comprising control (I), 10% spent straw (II), 20% spent straw (III) and 30% spent straw (IV) were tested in a cross-over design using 8 sheep. Dry matter intakes (DMI) were 74.0, 73.8, 70.2 and 57.1 and organic matter intakes (OMI) were 62.7, 63.4, 58.0 and 44.4 g per kg BW 0.75 for diets I, II, III and IV, respectively. DMI and OMI were significantly (p<0.05) lower for diet IV. Digestible OMI values were, respectively, 33.1, 32.6, 30.6 and 20.2 g per kg BW 0.75 for the 4 diets, which were significantly (p<0.05) different between the treatments. Inclusion of spent compost straw up to 20% of the diet did not affect the digestibility of DM, OM, crude fibre (CF), acid detergent fibre (ADF) and neutral detergent fibre (NDF), but the diet containing 30% compost straw had significantly (p<0.05) lower digestibilities. Nitrogen balance was also significantly (p<0.05) different between the treatments.