Ecofriendly Usability of Mushroom Cultivation Substrate as a Ruminant Feed: Anaerobic Digestion Using Gas Production Techniques

Simple Summary Ruminants might use process and agricultural by-products to meet their maintenance, growth, and production needs. Generally, feed is the major cost for an animal farm, yet utilization of agro-industrial waste (such as mushroom cultivation substrate) not only reduces these expenses, but could also help with the issue of environmental pollution. Accordingly, mushroom cultivation waste might be used for animal feeding after harvesting, because of its good-quality substrate, which is beneficial for ruminants. Therefore, the objective of this study was to evaluate the mushroom-cultivated substrate microscopic surface and its fermentability. Mushroom cultivation led to lower ether extract, acid detergent fiber, and crude fiber level of substrate. Our results show that biological treatment could reduce fiber components while increasing feed digestibility, providing new insight into the use of biological pretreatment to produce ruminant feed. According to the results, biological processing of mushroom cultivation substrate might increase in vitro fermentation. In conclusion, mushroom-cultivated substrate might be used as feed in ruminant diets. The current study was carried out to evaluate the nutritive value of mushroom-uncultivated and -cultivated substrates, and their in vitro gas and methane production. The experiment was conducted in a completely randomized design, and analyzed with GLM using SAS 9.4. Analysis of the structural morphology of mushroom-cultivated substrate was performed using a scanning electron microscope. Mushroom cultivation led to lower ether extract, acid detergent fiber, and crude fiber level of substrate (p < 0.05). Mushroom-cultivated substrate showed higher in vitro cumulative gas production (p < 0.05). Moreover, mushroom cultivation led to a higher sample surface, and improved the microorganisms' access to feed materials, thus stimulating rumen fermentation and increasing methane production (p < 0.05). The organic matter digestibility, metabolizable energy, and net energy lactation values were higher for mushroom-cultivated substrate than uncultivated substrate. The results demonstrate that mushroom-cultivation not only increases the contact surface of cellulose, leading to higher ruminal microorganisms' access to feedstuff, but could also had higher nutritive value; this material might be used in ruminant ration formulation, to reduce environmental pollution and feed costs.