Don Riesenberg


Don, a retired Naval Reserves Master Chief, founded Brookside Agra in 1985 on the premise that all-natural specialty additives were the future of the feed industry. He went on to co-develop a number of all-natural agricultural and environmental products, while growing the specialty feed additive business into a worldwide network, with products available in over 92 countries. Don was a true visionary, family man and patriot. Don remained active in the company until his death in June 2018 at age 83.    

Chad Vaninger

President and General Manager

A fifth-generation employee, Chad possesses the strategic vision necessary to achieve Brookside Agra’s business goals. Chad’s business style combines a unique blend of innovation, global team building and executive prowess.

Tim Nelson

Vice President - Animal Health & Nutrition Sales

Tim is responsible for developing and managing new and existing customers throughout North America, South America and Europe. Tim has more than 30 years of industry experience, including 20 years in animal nutrition sales, research and product development and 12 years in swine production management.    

Donna Horton

Director of Corporate Finance/Global Logistics

Donna processes all orders for both domestic and international shipments, performs general accounting duties including payables and receivables, coordinates business travel plans, conducts credit checks for all potential customers, and maintains product inventory and pricing.

618-628-8300 ext. 25

Mary Doerschuck

Product Registration & Compliance Manager

Mary coordinates product registrations, trademarks and renewals, and also handles our product tonnage reports, sales and customer service support, export documentation and accounts payable and receivable.