Source: HIGHLAND BREWING COMPANY, INC. submitted to
SPENT HOPS, YEAST AND TRUB FROM CRAFT BREWERIES FOR PROMOTION OF ANIMAL GROWTH AND METHANE REDUCTION IN RUMINANTS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
EXTENDED
Funding Source
Reporting Frequency
Annual
Accession No.
1015965
Grant No.
2018-33610-28499
Project No.
NC.W-2018-00413
Proposal No.
2018-00413
Multistate No.
(N/A)
Program Code
8.3
Project Start Date
Aug 1, 2018
Project End Date
Dec 31, 2019
Grant Year
2018
Project Director
Ashburn, B.
Recipient Organization
HIGHLAND BREWING COMPANY, INC.
12 OLD CHARLOTTE HWY STE 200
ASHEVILLE,NC 28803
Performing Department
(N/A)
Non Technical Summary
The growing craft brewing industry produces significant amounts of spent yeast, trub (grain proteins) and spent hops that are presently treated as waste. Their disposal can be a headache for the brewer and municipal waste treatment authorities. We have created a combination of these materials called THYM (Trub Hops Yeast Mix) and are developing it into an agricultural feed supplement for cattle. Based on our earlier work with spent craft yeast and anti-microbial hop acids, we expect THYM to improve livestock growth and reduce their production of methane. THYM should improve the digestive response and growth of cattle by altering the metabolism of their gut (rumen) microbes in a manner similar to conventional antibiotics. Commercialization of THYM as a feed supplement faces three major hurdles: a high moisture content-which make it difficult to transport and manipulate, an untested growth potential as a supplement, and a limited understanding of how it affects the cow's digestive response/very important rumen microbes. To address these problems, we will 1) evaluate several industrial methods for drying THYM suitable for a midsize craft brewery, 2) run a 2-month growth and metabolism study in Angus steers and 3) further investigate the natural products in THYM and their effects in the rumen. This ground work will help turn craft brewery byproducts into a commercial feed supplement that improves growth, reduces antibiotic use and lowers greenhouse gas emissions.
Animal Health Component
100%
Research Effort Categories
Basic
20%
Applied
70%
Developmental
10%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
3023310101030%
4032230202050%
1320430100010%
6015230301010%
Goals / Objectives
Project Goal:Craft Brewery side streams include significant amounts of spent yeast, precipitated grain proteins (trub) and spent hops. Disposal of these side streams is expensive, wasteful, not environmentally friendly, and burdens local municipal wastewater treatment plants. The GOAL of this proposal is to develop a patented process to manufacture an animal feed supplement - THYM (Trub, Hops, Yeast Mix) - with significant economic and agricultural value by repurposing co-products from craft breweries that are presently treated as waste. This mixture provides a valuable protein source, has natural antibiotic properties, reduces methane production in cattle, and can improve the rate of weight gain in animals. It addresses three USDA/NIFA/SBIR FY-2018 Research Priorities for Animal Production and Protection (Program Code 8.3): 1) Increase feed efficiency, 2) Develop alternatives to the use of antibiotics, and 3) Establish a technology that decreases greenhouse gas emissions. Project Objectives:Develop infrastructure at Highland Brewing Company for harvesting THYM.Evaluate cost and labor intensity of several small-scale drying methods to reduce the moisture content to 15% or less.Measure total nutritional parameters of THYM as produced and during experimental drying steps. Evaluate THYM as a feed additive in growing cattle diets.Extend knowledge of the effects of hop- and protein- rich co-products on bovine rumen metabolism using batch anaerobic cultures with bovine rumen microbe samples obtained at slaughter. Consolidate the results of experimentation noted above to develop a final process and product that can be sold or franchised around the world anywhere there are concentrations of breweries.
Project Methods
MethodsEfforts will be concentrated by the separate entities with the goal of developing enough data and knowledge to change the way that THYM is looked at by breweries, cattle producers, municipalities, and institutions of higher learning. Students at both NCSU and Warren Wilson College will be involved with data collection. The following breakdown shows the general arrangements.Develop the mechanical infrastructure at Highland Brewing Company for harvesting THYM. Address the question: Can this equipment be installed at a cost that will not deter other breweries from side streaming this important co-product?Realignment of stainless piping to properly locate pumps that will effectively move the yeast/hop slurry to the mixing tanks.New stainless piping to effectively collect hot trub from the whirlpool and move it to the mixing tanks.Additional glycol lines to temperature control the liquids and solids.Potential new steam line to storage tank to test ability of THYM to withstand high temperatures during storing or killing yeast.Dewatering filter bags: The "wet" THYM will be pumped to various porosity bags to gauge dewatering effectiveness. This will allow for the material to be moved around by shovel, skid steer, or other machines.Addition of organic acids to yeast/hop slurry to inactivate live yeast.Samples of 5, 50 and 500 lb will be stored 4, 21 and 38 ºC and tested for hop acid content, yeast viability and microbial (aerobic) contamination.Lab testing of all waste stream before, during, and after mixing to track the growth of natural yeast and bacteria. Correlate the effects of the time and temperature on the mixed product, thus allowing for variations in product and predictions of its overall effectiveness.At Highland Brewing Company evaluate cost, labor intensity and effectiveness of several small-scale drying methods to reduce the moisture content of THYM. Address the questions: Can this be done on a non-industrial, moderate scale? Can enough water be removed to keep material handling and transportation costs down?Test one or all of the following: belt press/filter press/centrifuge dewatering systems - These systems are designed to dewater to 15% moisture content. At this moisture content, the material can be pelletized and shelf stable.Drum drying trials by shipping THYM samples to a vendor that will evaluate the suitability of atmospheric, steam heated drum dryers for this material. Testing various drying techniques including rotary dryers, fluid bed dryers, agitated mixing dryers, flash dryers, and spray dryers.At NCSU facility, after dewatering goal is complete,the goal is to screen a new and novel brewer's byproduct feed (THYM) and assess its potential for producing high body weight gains, efficiency of feed to gain conversions, and an altered ruminal volatile fatty acid and plasma metabolite profile when compared to monensin (Rumensin®) in beef cattle diets. Address the question: Does THYM improve cattle performance and can it be used as an alternative to monensin?This study will be conducted at the NC Department of Agriculture's Mountain Research Station in Waynesville, NC, utilizing a half-covered drylot feeding facility with 45 weaned Angus steers (272 ± 11 kg). Dietary treatments will consist of 1) total mixed ration control diet (negative control), 2) total mixed ration with Rumensin® (positive control), and 3) total mixed ration with THYM (test diet). Experimental diets will primarily consist of corn silage with the addition of soybean meal and other by-product feeds, to balance protein level, and a mineral supplement to meet the animal's minimum requirements. Diets will be balanced to support a growth rate of 0.91 kg/hd/d. Rumensin® will be included in a formulated premix to offer 200 mg per head daily while THYM will be added to the total mixed rations at 2% (DM) to provide approximately 10 g per head daily of total hops bitter acids. A 14 d adaptation period will be used to acclimate steers to the pens and a silage-based diet, and will be followed by a 63 d experimental period. Sample collection:Both feed and feed refusals will be collected and analyzed for nutritive value. Steers will be weighed on two consecutive days at the beginning and end of the experimental period, and one weight will be obtained on day 21 and 42.Blood samples for analysis of blood urea nitrogen concentrations will be collected via jugular venipuncture.Ruminal fluid collected via stomach tube will be obtained two hours after the morning feeding, three times during the experiment.Response variables of average daily gain, dry matter intake, gain to feed ratio (feed efficiency), blood and ruminal metabolites will be statistically analyzed for significance.Investigators at Warren Wilson College will determine the variability in hop acid and prenylated flavonoid content between batches of THYM. They will extend our understanding of THYM potentials through batch anaerobic incubations with rumen microbes, measuring effects of THYM on ammonia, pH, short-chain fatty acid, and methane production for various substrates. Results with THYM will be compared to protein control incubations using baker's yeast and soy to normalize protein content and monensin as a positive control. Profile the hop acid and prenylated flavonoid content of THYM by HPLC analysis of extracts using UV detection and authentic standards.Conduct in vitro metabolism studies with bovine ruminal microbes obtained at slaughter from a local abattoir. Use anaerobic, batch 24 hr. incubations with substrates mimicking the feedlot studies. Compare the production of fermentation products including methane, ammonia, and acetate/propionate ratios with varying amounts of THYM supplement vs baker's yeast, soy protein and monensin controls. Examine the relationship of microbial metabolite production +/- THYM as a function of incubation time, pH and substrate composition in comparison to a standard monensin response. Evaluate potential for conversion in the rumen of xanthohumol to estrogenic 8-prenylnaringenin during microbial incubations with THYM.EffortsHighland Brewing CompanyLead the outreach to local citizens, environmental groups, and municipality to build momentum towards the potential Phase II of the project. Phase II will help create a true business model that will solve the many negative aspects of brewery waste.Representatives from Highland will join team members at conferences and presentations.NC State University/ Animal Feeding TrialScientific findings presented at national, peer reviewed conferencesResults disseminated at extension sponsored events and county cattlemen's meetingsExtension fact sheets on THYM handling and feedingWarren Wilson College in vitro bovine rumen microbial studiesInterest undergraduates in participating in these anaerobic studies Present at ACS and university-sponsored local science meetingsSubmit research findings to national microbiology or agricultural journalsConsider participating in a national rumen biology meeting in 2019Evaluation/MeasurementKey MilestonesAttain a THYM-related side stream productFind a process to reduce THYM water content to 50%Further reduce water content to 85%Supplementing feed at 2% THYM is practical and acceptable to stockMinimize loss of alpha and beta hop acids to <20% during drying Achieve steer growth enhancement with THYM over control dietsAchieve steer growth in THYM group comparable to monensin-treated groupDemonstrate that THYM improves P/A ratios and reduces methane production by rumen microbes in vitro to extent a similar to monensin.

Progress 08/01/18 to 07/31/19

Outputs
Target Audience: Nothing Reported Changes/Problems:Reviewers of our proposal expressed concerns that feeding hop-rich feeds could cause negative effectsdue to phytoestrogen exposure.Experiments are on-going to assess exposure levels in THYM fedanimals to XN and 8PN in rumen fluid samples and in blood. Blood samples from TMR and TMR+THYManimals have been sent off to Professor Jan Fred Stevens, Oregon State, Corvalis, OR for LC/MS/MSmeasurements (Stevens and Maier, 2016). This work was not originally considered in the Phase 1application, and therefore no money was budgeted for this work. It is expected to cost $4-5000and will be funded with money reallocated from the infrastructure budget for the project. Additional scope and unanticipated project managment needs necessitatedpayment for some additional consulting help. Payment for these services was pulled from underages on the brewery labor and facilities upfit budgets. What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals?As outlined in our interim technical report, submitted in early Augustand summarized above, we have several major areas of work remaining to complete the Phase 1 objectives. All of these will be completed by December 31, 2019 which is the end of our Phase 1 grant period. These major work areas are as follows: 1) Complete reviews of high-tech, larger scale dewatering technologies and processes. We have work ongoing and planned with major manufacturers and suppliers of dewatering equipment. This includes a variety of technologies including filter presses, drum dryers, and spray dryers. The goal of this work is to prove viability of these technologies, develop an understanding of potential process flows for production scale application, develop high level cost estimates and identify the appropriate next steps for further evaluation and research in subsequent phases. This work is being completed at Highland Brewing Company as well as at various manufacturers/ suppliers facilities. 2) Complete the in vitro studies using bovine rumin microbe samples as outlined in our application. This work is currently ongoing at Warren Wilson College and will be completed by the end of the grant period. 3) Finalize remaining data analysis from the feed trials that were completed, notably to conduct final analysis of feed efficiency for this study. This work is being conducted by NC State University and will becompleted by the end of the grant period. 4) The next section of this report (Changes / Problems) containsa detailed discussion of work that has been added to the scope of this project to address concerns that feeding hop-rich feeds could cause negative effects due to phytoestrogen exposure. This work is being conducted at Oregon State University and will be completed by the end of the grant period.

Impacts
What was accomplished under these goals? Project Impact As US and world population continues to grow, and in the face of a changing global climate, demand for products that improve feed efficiency, reduce disease, reduce greenhouse gas emissions and reuse waste by-products will skyrocket. As outlined in our original Phase 1 application, we have the potential to develop a feed supplement material comprised of natural, plant-based materials that are currently disposed of as waste in the craft brewing process. This feed supplement material provides a valuable protein source, has natural antibiotic properties, reduces methane production in cattle, and can improve the rate of weight gain in animals. The process we propose also has the potential to provide significant positive benefits to municipal wastewater treatment systems from reduced suspended solids loading and reduced Biological Oxygen Demand (BOD), both of which are significant issues in these systems. Our work thus far has provided positive indications in every area of research that support the benefits of this potential product and the feasibility of producing this at a reasonable cost. In summary, our 9-week feeding trial has been completed showing a positive trend of increased average daily weight gain with Rumensin® (7%) and THYM compared to a control. In addition, we have developed provisional infrastructure and processes to create THYM batches from a variety of craft beer styles. We have also conducted research on multiple approaches to dewatering and stabilizing THYM and have concluded that simple, low technology manual processes can cost effectively dewater THYM with high retention of valuable proteins and hop acids. Finally, we are conducting in vitro studies, which will help bolster the data proving the methane inhibiting properties of the hop acids found in THYM. The results of the work accomplished thus far strengthen our belief in the fundamental premise and value of this project, both commercially and in terms of societal good. Progress toward achieving objectives: Significant work has been completed toward accomplishment of the project objectives above. The Interim Technical Report, submitted on August 6, 2019 provides extensive detail on the work completed, including documentation of data, statistical analysis and preliminary conclusions. 1) Develop infrastructure at Highland Brewing Company for harvesting THYM. Major activities completed - work has been completed to develop the infrastructure required to harvest THYM, and to mix and store THYM temporarily prior to dewatering. This includes the purchase of a lobe pump, equipment to support large dewatering bags, and minor pipe infrastructure improvements. Data Collected - Data was collected for each batch on the input streams (e.g. the beer styles and batches collected for each batch of mixed THYM).Because craft brewing involves many different styles, every batch of THYM was unique in makeup. Each batch was carefully collected and the overall makeup was noted for review during the feeding study. Subsequent collections were small for specific drying technologies, but the overall makeup of the THYM followed the same similar procedures. This work has been completed in full. 2) Evaluate cost and labor intensity of several small-scale drying methods to reduce the moisture content to 15% or less. Major activities completed - Significant work has been completed on evaluation and testing of low technology/ small volume processes. Work is in progress on the evaluation of several high tech, industrial scale solutions. Data Collected - See interim technical report for data collected on filtration rates, moisture content, retention of proteins and hop acids and other key statistics. The end result of this work will be the cost/benefit analyses of all the technologies that will help to guide technology used, test the usability of the product, and identify technologies that are appropriate for individual end users. Summary statistics and discussion of results - See interim technical report Key outcomes or other accomplishments realized - The results of the work to date has proven that small scale, low-tech solutions can effectively reduce moisture content to a range of levels, including as low as 10% when coupled with air drying. These studies have also proven a high rate of retention of valuable proteins and hop acids. This work is approximately 50% complete, with ongoing work to explore larger scale technologies and processes. 3) Measure total nutritional parameters of THYM as produced and during experimental drying steps. Major activities completed - For each batch of THYM data was collected on mix pH, hop acid content, protein content and percent dry matter. Data Collected - See interim technical report for data collected on retention of proteins and hop acids and other information on the results of dewatering/ drying. Summary statistics and discussion of results - The results of the work to date has proven that small scale, low-tech solutions to dewater THYM result in a high rate of retention of valuable proteins and hop acids. Key outcomes or other accomplishments realized - The outcomes thus far support the premise that THYM can be dewatered without losing the beneficial proteins, yeast and hop acids. Ongoing work is underway to evaluate the shelf stability of the dried THYM. This work is ongoing. 4) Evaluate THYM as a feed additive in growing cattle diets. Major activities completed - Completion of nine week feeding trial, described in detail in the Technical Report. Data Collected - Feed ration mix data for the experiment, average daily gain, feed efficiency, serum urea nitrogen (SUN), short chain fatty acid (SCFA) concentrations. Summary statistics and discussion of results - Work is still underway to fully analyze the feed trial results, however average daily gain did show a positive trend for THYM versus the control group. Key outcomes or other accomplishments realized - Preliminary results provide favorable evidence that THYM may enhance animal growth and feed efficiency. As such, THYM may provide protein supplement benefits that allow for a reduction in other, potentially more expensive protein in the feed ration mix. This work is largely complete, with the exception of a few remaining data analysis tasks. 5) Extend knowledge of the effects of hop- and protein- rich co-products on bovine rumen metabolism using batch anaerobic cultures with bovine rumen microbe samples obtained at slaughter. Major activities completed - Experiments are ongoing to strengthen our hypothesis that alpha and beta hop acid are responsible for the methane and SCFA modulations seen when spent craft brewers yeast is incubated with rumen microbes. This work is ongoing and will be concluded by the end of the Phase 1 Grant. 6) Consolidate the results of experimentation noted above to develop a final process and product that can be sold or franchised around the world anywhere there are concentrations of breweries. At the conclusion of the Phase 1 grant period we anticipate completing all of the objectives identified in the application as well as additional objectives added to the work subsequent to the application and described later in this progress report. At that point we expect to have developed a roadmap to further evaluate and perfect the production process including batch mixing, dewatering, stabilizing and finished product production.In subsequent phases of work we anticipate the need to expand feeding trials to include larger populations, different segments of the feeding cycle and varying dosage in the feed mix. We may also expand these feeding trials to other animals and organisms. We expect to develop a work scope document detailing the recommended additional feed trials. Finally, we will have a full set of in vitro studies on the effects of THYM on bovine rumen metabolism, which will likely inform recommendations for further studies, including potential in vivo studies.

Publications