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Farmyard and backyard chickens the world over have long been the happy recipients of family table scraps as a part of their regular diets, allowing households to not only reduce their food waste but to decrease the demand for new resources over the course of a chicken's lifetime by feeding them what might otherwise go into the trash or compost.

Commercial poultry enterprises may not be feeding their livestock the carrot tops or sweet potato scraps from last night's stew, but that doesn't mean that mushroom stems are off the proverbial table.

Associate professor of biotechnology Venkatesh Balan and professor of mechanical engineering technology Weihang Zhu were recently awarded $750,000 of a $2 million grant by the USDA National Institute of Food and Agriculture (NIFA) to conduct groundbreaking work into the development of a new poultry feed additive made from mushrooms.

This supplement will make use of stem pieces that are currently discarded as waste by the commercial mushroom production industry to increase the nutritive value of poultry feeds. This will hopefully lead to healthier livestock, better quality meat from broilers and better quality eggs from laying hens.

"This USDA program is specifically focused on organic agriculture and producing organic products. One of the biggest challenges for the poultry industry is sustainable, organic practices and production,” Balan said. “Soybean meal is considered a good animal feed, but the cost and demand for soybeans is increasing due to the increasing world population and decreasing available land. Since we are using soybeans to feed humans, too, the available raw material for animal feed is decreasing.”

This work is part of a larger partnership between UH, Prairie View A&M University (PVAMU) and the University of Georgia (UGA) to improve upon existing organic poultry feed practices. The project is broken down into three components.

At UH, researchers will work to improve commercial mushroom harvesting practices and reduce waste by processing mushroom stems that would otherwise be discarded into a shelf-stable, high-protein poultry feed additive.

At PVAMU, the dried mushroom stem (DMS) powder will be mixed with other commercial feed ingredients and fed to chickens, whose meat and eggs will then be evaluated for their quality and nutrient content.

And at UGA, chickens sustained with this new blended feed will be challenged with diseases that currently pose significant threat to poultry populations with the goal of better understanding how DMS may bolster pathogenic immunity.

By making use of the middle stem section usually discarded due to current harvesting practices, this approach turns unused agricultural byproduct into a useful and more sustainable resource, thus reducing the strain on existing feed crops. This re-purposing of stems as feed not only reduces waste and diversifies demand but may also in fact increase the quality of the meat and eggs produced as a result of their use.

"In the mushroom processing industry, the time to harvest is about a 100-day process,” Balan said. “There are 20 to 25 days of composting, six days of pasteurization, and then the remaining 70 days of mushroom cultivation until harvest. The caps are harvested and sent to markets. The stems are discarded to the landfill.”

“The Monterey mushroom facility located a two-hour drive from her-e produces about 40 tons of mushrooms a day, so every day they are throwing our four tons of mushroom stems," Balan continued. "This is already being produced and discarded every day. Why not clean them up, freeze dry them, grind them into a powder and use them? We could produce close to half a ton of dry mushroom stem powder for the poultry industry every day. We're basically turning trash into gold."

Though these stems may currently be thrown away as trash, Balan and his team intend to change that – and thereby reduce food waste from the very beginning of the supply chain – by showcasing their indispensable potential for non-human applications that ultimately create even more value.

"By demonstrating the feasibility of this undertaking, the U.S. could become a global leader in producing organic, climate-smart mushroom food and feed products," he said.