Rock River
Laboratory, INC.

Rock River Laboratory Experts

Expertise to serve your needs

Don Meyer, Rock River Laboratory President and OwnerDon Meyer

President and Owner                                                        
Don Meyer graduated from the University of Wisconsin, Milwaukee with a Bachelor of Science degree in geography in 1975. Shortly after, he attended graduate school at the University of Wisconsin, Madison and the University of Wisconsin, Milwaukee. Don’s passion for science and analysis combined with a little support from a local agriculture retailer, helped him build Rock River Laboratory agriculture analysis, which opened in 1976 and is running strong in the fields of agronomy, feedstuff, manure and water analysis yet today. Don’s progressive thinking made him an early adopter of near infrared (NIR) technology as an analysis tool, and his work with this technology has forged new frontiers in the use of NIR technology in the lab and on-farm. Read More One of the original founders of the National Alfalfa Hay Testing Association (now known as the National Forage Testing Association), Don served as the Chairman of the organization twice. Don also served on the Board of Directors for the NIR consortium and was the only private industry member of the USDA-NIR Forage Network. Striving for industry progress by improving analysis accuracy and incorporating new technologies and tools, Don has remained dedicated to helping agronomists, nutritionists, producers, and growers achieve success through improved outputs. 

Don can be reached at: don_meyer@rockriverlab.com


Zachery Meyer

Zachery Meyer, Rock River Laboratory Director of Operations
Director of Operations
Raised in Ixonia, Wis., Zachery Meyer grew up immersed in his family’s business, Rock River Laboratory. Meyer spent many hours helping in various jobs around the laboratory, seeing first-hand the dedication and commitment his father and the late Twilah Kulow had to the business and their customers. Meyer went on to attend the University of Wisconsin-Milwaukee and in 2006 earned a Bachelor of Arts degree in Journalism. After moving to Los Angeles and gaining experience in outside TV commercial sales while there, Meyer returned to his home state to garner more sales experience at various companies – both large and small. In 2007, Meyer resumed his involvement in Rock River Laboratory, starting as a soil sampler, moving to outside sales and eventually taking on his current role of director of operations. Read More Meyer still gathers inspiration from the Rock River Laboratory employees and mentors who cultivated his drive for customer satisfaction and service, while continuing to learn and deepen his understanding of animal nutrition and agronomy. When he isn’t building relationships with customers or overseeing laboratory operations, Zac spends his time playing or watching sports and sharing in family time with his wife and two young daughters. 

Zac can be reached at: zachery_meyer@rockriverlab.com


Dustin Sawyer, Rock River Laboratory Lab Director

Dustin Sawyer

Laboratory Director
Born and raised in Wisconsin, Dustin Sawyer gained a love of the outdoors, mechanics and engineering throughout his years growing up near the town of Wisconsin Rapids. In 2004, Sawyer earned his Bachelor of Science degree in Soil Science and Chemistry from the University of Wisconsin- Steven’s Point. That same year, he put his vast conservation knowledge and experience toward an internship for the Wood County Land Conservation Department, where he worked with growers on implementing preservation practices throughout their operations. Guided by a desire for continued learning and passion for science, Sawyer is in progress toward earning his Master’s Degree in Soil Science through the University of Wisconsin – Madison. He continues his over ten-year tenure at Rock River Laboratory headquarters as the Laboratory Director, guiding the direction of lab analysis practices, processes, quality assurance and quality control with a detailed eye. Read More He maintains involvement in key industry groups through his memberships in the Soil and Water Conservation Society, the Soil Science Society of America, the American Society of Agronomy, the Crop Science Society of America, and is a board member on the Soil and Plant Analysis Council, and the Illinois Soil Testing Association. Sawyer still finds time outside the lab to enjoy the outdoors that brought him to where he is today through kayaking, fishing and exploring.

Dustin can be reached at: dustin_sawyer@rockriverlab.com


John Goeser, PhD, PAS, Diplomate ACAN

John Goeser, PhD, Rock River Laboratory Director of Animal Nutrition, Research, and Innovation
Animal Nutrition, Research and Innovation Director
John Goeser grew up in the agriculture industry as his family’s dairy near Plymouth, Wis.  grew from 60 head in the 1980’s to now over 1,000 cows. After earning Bachelor of Science degrees in Dairy Science and Agronomy at the University of Wisconsin-Madison, Goeser earned a Master of Science degree in Plant Breeding & Genetics as well as a Master of Science degree and Ph.D. in Dairy Science from the University of Wisconsin-Madison. After gaining experience in graduate school as a nutritionist, and moving to a technical nutrition and support position within the feed industry, Goeser started his tenure with Rock River Laboratory in 2012. In his current role with Rock River Laboratory, Goeser oversees animal nutrition, technical support, and research, specifically centering his focus on carbohydrate digestion, forage management and trends, and more recently, feed hygiene. Read More Through an adjunct assistant professor appointment with the University of Wisconsin- Madison Dairy Science Department, Goeser contributes lectures discussing carbohydrate digestion, rumen metabolism and forage preservation to the future of the dairy industry. 

John can be reached at: johngoeser@rockriverlab.com


Lauren Meyer, Quality Control and Product Development Director

Lauren Meyer

Quality Control and Product Development Director 
Hailing from Ixonia, Wis., Lauren Meyer grew up in the midst of her family’s business, Rock River Laboratory. After spending many childhood hours at the lab helping with everything from folding filter papers to stickering soil analysis bags, Meyer came back to the laboratory every summer between her college years to assist in the Rock River Laboratory soils department. In 2007 she earned her bachelor’s degree in Psychology from the University of Wisconsin-Milwaukee and decided to follow her passion back to the family business. She joined the Rock River Laboratory team full time in first the agronomy department, then in the nutrition department, all while finding great appreciation for the opportunity to work alongside her father, Don, and brother, Zachery,  with the common goal to make Rock River Laboratory one of the best in the industry. Read More Since then, Meyer has taken on the role of forage lab supervisor, and eventually quality control and product development director, where she works to review and deliver laboratory results, support suppliers, maintain quality control programs, and assist in developing both calibrations and new products. 

Lauren can be reached at: Lauren_Meyer@rockriverlab.com


Eva Lynch
Eva Lynch, Rock River Laboratory Wet Chemistry Lab Supervisor
Wet Chemistry Lab Supervisor
Born and raised in Watertown, Wisconsin, Eva Lynch grew up in the midst of a prime agriculture pocket, and spent most of her youth involved in the 4-H Horse and Pony Project. Her passion for science and technology drew her to earning an Associate’s degree in Biotechnology from Madison Area Technical College-Truax in 1998. After college, Lynch utilized her skill base in various roles during her career build – including quality control lab technician testing milk replacer ingredients and final products, organics laboratory technician analyzing water and soil for contaminants, and as a GCMS specialist, assisting the company in earning ISO accreditation for phthalates analysis in plastics. Lynch joined Rock River Laboratory in 2014, and her vast experience in High Performance Liquid Chromatography (HPLC), Gas Chromatography (GC), and Mass Spectrometry (GC-MS) technology has helped Rock River Laboratory continue to lead the industry Read More in use of the latest technology for accurate, quality analysis. When she isn’t overseeing the wet chemistry laboratory, Lynch can be found horseback riding, gardening and spending time with her children. 

Eva can be reached at: eva_lynch@rockriverlab.com


Bryan Gatzke, Rock River Laboratory Soil Lab SupervisorBryan Gatzke

Soil Lab Supervisor
Born and raised near Watertown, Wis., Bryan Gatzke cultivated a life-long love of agriculture and conservation while helping his family raise chickens and turkeys, and helping milk cows and make hay at neighboring farms. He followed this passion to studying the field of Conservation and Environmental Sciences at the University of Wisconsin-Milwaukee, where he graduated with a Bachelor of Science degree in 2012. During his college tenure, Gatzke was involved in Lake Michigan beach cleanup and water testing and held an internship that involved Environmental Management System plan writing.  He joined Rock River Laboratory in 2013 and has applied his vast experience in everything from mechanics to tech support to advancing the Rock River Laboratory agronomy laboratory. Read More Continuing his dedicated involvement in conservation and soil science, Gatzke is active on the Illinois Soil Testing Association Board of Directors, is acting safety officer for Rock River Laboratory and has spearheaded Rock River Laboratory’s inclusion in the sustainability initiatives assessment program known as the Green Master’s Program. When he isn’t running the soil laboratory, Gatzke spends time playing softball and guitar, playing with his children, and enjoying the roots of conservation – hunting, fishing and hiking. 

Bryan can be reached at: bryan_gatzke@rockriverlab.com


Doug Arterburn, Rock River Laboratory Information Technology Project Manager

Doug Arterburn

Information Technology Project Manager
Born and raised on his family’s 160-acre diversified farm near Greenfield, Iowa, Doug Arterburn attended college in his home state, graduating from Iowa State University in 1978 with a Bachelor of Science degree in Computer Science. Arterburn found a way to combine his specialty skill set and background in agriculture through roles as a systems programmer and applications programmer, handling database management, network management, and firewall management for large agriculture companies, all before joining the Rock River Laboratory team in 1981. Arterburn’s vast experience in agricultural programming has helped, and continues to keep Rock River Laboratory on the forefront of technology for the past 35 years. From the time of his first Rock River Laboratory project, writing “Personalized Dairy Rations” using an Apple II computer in Applesoft Basic, Read More Arterburn’s extensive tenure has afforded him the opportunity to witness and participate in the exponential growth and adoption of new technology in agriculture. When he isn’t writing code, Arterburn enjoys the outdoors and still fosters his competitive spirit through Frisbee golf, tennis, hiking and reading. 

Doug can be reached at: doug_arterburn@rockriverlab.com

Buffy UglowBuffy Uglow

Marketing and Communications Director
Raised on a small farm near Melrose, Wis., Buffy Uglow developed a passion for agriculture at a young age while helping her family raise Belgian Draft Horses and later working with her sister and brother-in-law’s cow-calf operation. This passion drove her to focus on Animal Science and Life Sciences Communication at the University of Wisconsin-Madison, and she nurtured her agriculture experience through internships with the University of Wisconsin Equine Extension and an agriculture marketing firm. After earning a Bachelor of Science degree in 2008, Uglow took on marketing executive role for an agriculture marketing agency, spending time writing, developing producer and grower-directed materials, leading advertising campaigns and planning marketing strategies for various feed, reproduction, and pharmaceutical companies. Uglow joined Rock River Laboratory in 2014 and has utilized her past experience to expand media and public relations and facilitate the Read More growing marketing and customer relationship needs of the team. She is actively involved on the Wisconsin State Fair Dairy Promotion Board and the Wisconsin Farm to Table Committee, and when Uglow isn’t writing or designing, she spends her time with her husband and dog, helping on her in-laws dairy farm, and capturing agriculture through the lens of her camera. 

Buffy can be reached at: buffy_uglow@rockriverlab.com

Larry McRoberts, Rock River Laboratory Customer Service RepresentativeLarry McRoberts

Customer Service Representative
Hailing from Eau Galle, Wis., Larry McRoberts spent his early years working on his family’s livestock and crops farm. His work with everything from hogs, poultry and dairy cows, to beans and alfalfa, instilled a love of all agriculture and drew him to an agricultural college. McRoberts earned his Bachelor of Science degree in Agricultural Education from the University of Wisconsin-River Falls in 1968. Since that time, McRobert’s earned experience has included roles as district sales representative - with sales in feed, agronomy, fuel and general ag products from hardware to animal health, district feed sales manager, and state manager of a retail sales force, which involved recruiting and leading training in products and sales. McRoberts joined the Rock River Laboratory team as a customer service representative in 2012, and has continued building relationships around Wisconsin and Minnesota ever since. Read More His inspiration and guiding rule to treat others as you would like to be treated has afforded him many lasting relationships, and no industry event passes without someone sharing their acquaintance with McRoberts. When he isn’t meeting new people or visiting old industry friends, McRoberts can be found outside – getting back to his roots of gardening, hunting, fishing, trapping and teaching this all to the next generation, his grandsons. 

Larry can be reached at: larry_mcroberts@rockriverlab.com


Scott Fleming, Rock River Laboratory Nutrient Management Specialist and Soil Sampling Coordinator

Scott Fleming, CCA, TSP

Nutrient Management Specialist and Soil Sampling Coordinator
Hailing from Elkhorn, Wis., Scott Fleming first sprouted his love of agriculture while working on a small beef and pulling horse farm in high school. Along with custom baling service work, this experience nurtured his desire to seek a Bachelor of Science degree in Soil and Land Management from the University of Wisconsin-Stevens Point. An internship with the Natural Resources Conservation Service (NRCS) further solidified his decision to pursue a career in the soil and land conservation field, after graduating in 2004. Fleming’s vast field knowledge draws from previous roles in the agriculture retail industry, applying fertilizer and pesticides, sampling soil and tissues and nutrient management planning (NMP), which he still performs today. He joined the Rock River Laboratory team in 2008, specializing in site-specific soil sampling (grid sampling) and VRT applications. Read More He and his family raise Berkshire hogs and grow cash crops, in addition to his role as the official Rock River Laboratory pig roaster. When he isn’t reviewing farms for plans or soil sampling, Fleming can be found restoring antique tractors, fishing, hunting, and snowmobiling. 

Scott can be reached at: scott_fleming@rockriverlab.com


Randy Busch, Rock River Laboratory Nutrient Management SpecialistRandy Busch, CCA, TSP

Nutrient Management Specialist
Hailing from Burlington, Wis., Randy Busch earned his Bachelor of Science degree in Soil Science from the University of Wisconsin-Stevens point in 1991. His college major lead him to a variety of key industry roles as a soil laboratory director, crops specialist, precision farming coordinator and nutrient management specialist, all while he earned his credentials as a Certified Crop Advisor (CCA) and Technical Service Provider (TSP). Busch joined Rock River Laboratory in 2001, bringing his extensive knowledge in writing Nutrient Management Plans (NMP) and Comprehensive Nutrient Management Plans (CNMP) to the team. This vast experience allows him to work closely with confined animal feeding operations (CAFO) with or in process of obtaining Wisconsin Pollutant Discharge Elimination System (WPDES) permits. Read More When Randy isn’t on farm reviewing operations or writing NMPs, you can find him enjoying the outdoors that drew him to this career path – hunting, fishing, camping and hiking. 

Randy can be reached at: randy_busch@rockriverlab.com


Matt Luther, CCA, TSPMatt Luther, Rock River Laboratory Nutrient Management Specialist

Nutrient Management Specialist
Growing up in Colby, Wis., Matt Luther sprouted his experience in agriculture at a young age through work on a local, small dairy farm, where he worked from grade school through his college years. Luther followed his agriculture roots and passions to earning a Bachelor of Science degree in agriculture from the University of Wisconsin-River Falls in 1995. After several years gaining vast field experience as a crop production specialist for various cooperatives, Luther joined Rock River Laboratory as a Nutrient Management Specialist in 2006. Luther is a Certified Crop Advisor (CCA) and certified Technical Service Provider (TSP) with specialty proficiency in USDA programs and county ordinances, crop diagnostics, soil test recommendations, crop budgets, pesticide and fertilizer recommendations, and inventory management - Read More offering customers added value and expert insights for their Nutrient Management Plans (NMPs). When he isn’t on-farm reviewing operations for conservation planning, Matt can be found spending time with his family, running, fishing, and cooking. 

Matt can be reached at: matt_luther@rockriverlab.com


Jen Walton, CCA, CNMP, TSP

Jen Walton, CCA, TSP

Nutrient Management Specialist
Jen Walton grew up helping on her family’s beef farm outside of Hastings, Minn. Her passion for the agriculture industry spurred her on to earning a Bachelor of Science degree in Agronomy from the University of Wisconsin-River Falls in 2000.  She has previous work experience at the Central Wisconsin Windshed Partnership as the Program Coordinator, as well as holding Precision Ag Coordinator and Agronomist positions with an agriculture retailer before joining the Rock River Laboratory Nutrient Management Planning (NMP) team in 2010. Jen is a Certified Crop Advisor (CCA), Certified Comprehensive Nutrient Management Planner (CNMP), and certified Technical Service Provider (TSP) with experience in GPS soil sampling, variable rate fertilizer recommendations, and GPS equipment, including planting and yield monitors, guidance, and clutch and boom control. Read More Walton’s interest in new technology, including software, apps, and gadgets drives her to continuous improvement of work and life management.  When she isn’t busy reviewing farm operations to develop Nutrient Management Plans, Walton enjoys the outdoors, walking, fishing, boating, snowmobiling, riding motorcycle, and spending time with her family. 

Jen can be reached at: jenwalton@rockriverlab.com


Devin SawyerDevin Sawyer, Rock River Laboratory Executive Assistant

Executive Assistant
Growing up in the Central Sands of Wisconsin, Devin Sawyer attended school in the district of Wisconsin Rapids, Wis.  After earning her degree in Business Administration as an Administrative Professional, Sawyer grew her passion for science and agriculture working in the Rock River Laboratory agronomy laboratory, where she had the opportunity to see behind the scenes of the operation. She fostered this new found agriculture interest as she grew into her current role, which includes reviewing and assembling over 300 Nutrient Management Plans (NMPs) per year. Her knowledge gained from a comprehensive look at the industry from small to large farms offers the whole Rock River Laboratory team outside insight. Read More When Devin isn’t managing the Rock River Laboratory Watertown headquarters office or reviewing NMPs, she can be found outdoors – enjoying camping and kayaking, gardening and capturing fantastic outdoor scenes on camera. 
 

Devin can be reached at: devin_sawyer@rockriverlab.com

Chad Henke, Rock River Laboratory ControllerChad Henke

Controller
Growing up in Ashwaubenon, Wis., Chad Henke spent his younger years enjoying frequent visits to his grandparent’s cash crop farm and aunt and uncle’s small dairy farm. He went on to pursue his interest in business, earning a Bachelor of Business Administration degree in 2001 from the University of Wisconsin-Milwaukee, in the areas of Real Estate Development and Finance, with a minor in Urban Planning. After college, Henke put his degree to work as a financial analyst conducting accounting and financial analysis for a mid-sized medical real estate development company. In 2013, Henke joined the Rock River Laboratory, assuming the role of controller and taking on both accounting and logistics needs of the business. Read More In his free time, Henke can be found enjoying time with his family, as well as waterskiing, boating and ice skating. 

Chad can be reached at: chad_henke@rockriverlab.com 

Tabitha Kumbier, Rock River Laboratory Forage Data and Customer Support ManagerTabitha Kumbier

Forage Data and Customer Support Manager
Born and raised in Watertown, Wis., Tabitha Kumbier spent her youth raising and showing sheep and beef cattle at the local, state, and national levels. A long-time 4-H and FFA member, Kumbier credits her agriculture passion to her heavy involvement in judging competitions, speaking contests and assisting other youth at local education events through these agriculture organizations. She followed her agriculture roots to the University of Wisconsin-Platteville, where she earned a Bachelor of Science degree in Agriculture Business with a Marketing and Communications emphasis and an Animal Science minor in 2013. Before joining the Rock River Laboratory team, Kumbier held roles as a calf feeder at a local dairy, an intern with the Wisconsin Beef Council, and an intern with an artificial insemination company. In her role as the forage data and customer support manager for Rock River Laboratory, Kumbier is a liaison between the laboratory analysis team and agronomy and nutrition customers Read More - providing information, answering questions, problem-solving, and entering data for successful results. In her free time, Kumbier enjoys hunting and fishing, snowmobiling, and crafting, and has competed in turkey calling contests at the State and National Wild Turkey Federation Conventions. 

Tabitha can be reached at: tabitha_kumbier@rockriverlab.com 

Jacob Karlen

Jacob Karlen, Rock River Laboratory NIR Manager

NIR (Near Infrared) Manager
Growing up on a farm near Monticello, Wis., Jacob Karlen developed a love for agriculture while helping his family run their 80-cow dairy, and through his involvement in his high school FFA chapter, including serving on the officer team and attaining his American Degree. This passion grew into an appreciation for the biological sciences, and lead Karlen to pursue a Bachelor of Science degree in Biochemistry from the University of Wisconsin-Madison, in 2008. Karlen further developed his scientific research skill set while contributing to sample processing and scanning at the USDA-ARS-Dairy Forage Research Center (DFRC) while on campus earning his first degree. After taking a hiatus from the DFRC to pursue a feed company Quality Assurance-focused internship, Karlen returned to expand his involvement with NIR operations, developing his interest in this technology, and shuttling him into a role with the NIRS Forage and Feed Testing Consortium (NIRSC). This experience grew his capabilities and desire to pursue data handling and statistics. Prior to joining Rock River Laboratory in 2015, Karlen served as a laboratory technician and data manager for the NIRSC. In his current role as NIR Manager for Rock River Laboratory, Karlen works to track, manage, and maintain Rock River Laboratory’s extensive network of NIR instruments Read More – both domestic and abroad. He is also continuing his education, pursuing a Master of Science degree in Biological Systems Engineering, with a project focusing on portable NIR instrumentation. 

Jacob can be reached at: jacob_karlen@rockriverlab.com

Nathan Hrnicek, Rock River Laboratory Technical Nutrient AdvisorNathan Hrnicek

Technical Nutrient Advisor
Born and raised on a 700-acre farm in Seward, Nebraska, Nathan Hrnicek discovered his niche in agriculture while helping grow and harvest corn, soybeans, milo, and alfalfa, and raising beef and hogs on his family’s cow-calf operation and hog farm. Hrnicek went on to attend Ivy Tech Community College in Lafayette, Indiana, where he earned an Associate’s degree in agriculture in 2016. Since his time on the farm, Hrnicek has garnered over eight years of agriculture sales experience. In his role as a seed company district manager, Hrnicek focused on forage consulting and sales while forging long-term relationships and improving Return on Investment for his farmer and producer customers. In his current role as a technical nutrient advisor for Rock River Laboratory, Hrnicek consults with agronomists and nutritionists to build relationships, share insights and develop new opportunities for customer success. Read More Outside of his daily career, Hrnicek is an Indiana Dairy Producers industry advisor and enjoys spending time with his wife and four children, playing sports, and experiencing the outdoors. As a self-proclaimed nerd, Hrnicek also enjoys exploring new technologies and is happy to play a song on his accordion for interested parties. 

Nathan can be reached at: nathan_hrnicek@rockriverlab.com

Megan Kelly

Nutrition Analytic Consultant
Megan Kelly, Rock River Laboratory Nutrition Analytic Consultant
Hailing from Jefferson, Ohio, Megan Kelly became highly involved in 4-H and showing small animals at a young age. This early animal interest grew into a strong passion for production livestock, eventually driving her toward The Ohio State University to pursue a secondary education, focusing on Animal Science and Agribusiness. During her tenure at the university, Kelly was a member of the meat judging team, took on a role working at a small beef farm, and held internships at a feed company hog production farm and at The Ohio State University Equine 4-H.  Kelly earned her Bachelor of Science degree in 2014, and went on to a work as a swine technician in the farrowing department at a livestock operation in Bucyrus, Ohio. Kelly later moved toward a career in dairy nutrition, and garnered experience as an independent nutrition consultant in Northeast Ohio while milking cows and feeding calves on a local dairy farm. In her role as a nutrition analytic consultant for Rock River Laboratory, Kelly manages the day-to-day quality analysis of all samples passing through Rock River Laboratory-Ohio while building relationships and sharing insights for success Read More with Northeastern and Midwestern US-based nutritionists. Outside of her nutrition role, Kelly enjoys fitness, reading, blogging, and showing her family’s Belgian draft horses. 

Megan can be reached at: megan_kelly@rockriverlab.com

Kelsie Brennan, Rock River Laboratory-Northeast Lab ManagerKelsie Brennan

Lab Manager, Rock River Laboratory-Northeast
Born and raised near Wyoming, N.Y., Kelsie Brennan was rooted in agriculture from a young age thanks to her family's business raising Limousin beef cattle, and her involvement in 4-H showing registered Jerseys at the local and state fair level as well as raising market hogs. This agriculture passion grew as she worked on local family dairy farms throughout high school and into her college years. Brennan earned an Associate's degree in Agricultural Business from Alfred State College in 2011 and utilize her agriculture skill set to start a career  as a laboratory technician at an agriculture laboratory in New York. Brennan moved on to another analytical agriculture laboratory before joining Rock River Laboratory in 2016. As the laboratory manager for Rock RIver Laboratory-Northeast, Brennan oversees all analysis at the lab while manager her additional team members and maintaining customer relationships. Read More  In her free time, Brennan enjoys showing dairy cattle, baking, hunting, kayaking, and spending time outdoors, along with traveling back toher hometown in western New York regularly to visit her family. Now residing in Marathon, N.Y., home of the Central New York Maple Festival, Brennan has learned and even participated in the long lost art of maple syrup production. 

Kelsie can be reached at: kelsie_brennan@rockriverlab.com

Jeff DeGroot

Lab Manager, Rock River Laboratory - West
Megan Kelly, Rock River Laboratory Nutrition Analytic Consultant
Hailing from Fresno, Ca., Jeff DeGroot spent much of his childhood helping on his family’s 1600-cow dairy farm. These roots developed and secured his passion for a life and career in the dairy industry, which eventually carried him to a field technician role with the local Dairy Herd Improvement Association (DHIA). DeGroot joined Rock River Laboratory in 2009 as the manager of Rock River Laboratory-West in Visalia, Ca. In his role there, DeGroot overseas processing of samples submitted at that location while maintaining customer relationships. In his free time, DeGroot enjoys camping with his family, hunting, and riding UTV/ ATVs. 

Jeff can be reached at: jeff_degroot@rockriverlab.com

Mary Rosiejka, Rock River Laboratory-North Central WI Lab ManagerMary Rosiejka 

Lab Manager, Rock River Laboratory - North Central Wisconsin
Born and raised in Chicago, Ill., Mary Rosiejka moved with her family to a dairy farm in Withee, Wis. at the age of 14. Until her high school graduation in 1976, Rosiejka worked side-by-side with her father both in the barn milking cows and in the fields tending to the crops. Rosiejka's time on the farm gave her a deep appreciation for the agriculture way of life. Prior to her time at Rock River Laboratory, Rosiejka garnered experience as a grocery store produce manager and took on several roles within the customer service realm in various industries - including trucking, saw milling, and in cheese distribution. Her vast experience and well-rounded background have helped shape her successful management of Rock River Laboratory-North Central Wisconsin, in Colby, Wis., where she runs all Near Infrared (NIR) analysis Read More samples submitted there while managing client relationships. Outside of her weekday career, Mary enjoys do-it-yourself projects, woodworking, four-wheeling, spending time outdoors, and soaking in time with her mother, husband, son, daughter, son-in-law, and granddaughters. 

 


Mary can be reached at: Mary_rosiejka@rockriverlab.com

Art TessmannArt Tessmann, Rock River Laboratory Technical Support, Agronomy

Technical Support, Agronomy 
Growing up on a diversified crop and livestock operation near Cambria, Wis., Art Tessmann developed his passion for agriculture at a very young age. Tessmann went on to attend the University of Wisconsin-Madison as an Animal Science major through 1983, then shifted into the role of president and co-owner within his family's beef, swine, and crop operation. His extensive skill set in livestock management and marketing, and business and crop management, combined with Tessmann's further education experience, has offered continuous value to his customer and partners. His farming invovlement also helped Tessmann meet his wife, who he spent most of his life competing against in the livestock show ring. Shifting his focus to the agronomy sector, Tessmann moved into seed sales and management, where he assisted several organizations in strategically improving and growing their brand presence, accounts, and sales team. Tessmann joined the Rock River Laboratory team in 2017 within agronomic technical support, Read More helping to facilitate relationships, solve customer challenges, and fulfill customer needs through the use of convenience tools. When he isn't supporting customers, Tessmann can be found golfing, helping on his family's farm, cycling, or actively serving his community. 

Art can be reached at: Art_tessmann@rockriverlab.com 

Rock River Laboratory

Founded in 1976, Rock River Laboratory is a family-owned laboratory network that provides production assistance to the agricultural industry through the use of advanced diagnostic systems, progressive techniques, and research-supported analyses.  Employing a team of top specialists in their respective fields, Rock River Laboratory provides accurate, cost-effective, and timely analytical results to customers worldwide, while featuring unsurpassed customer service.

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