The major new dry-milk plant could cause big waves in the Churchill County economy.Among the likely beneficiaries are truckers that would haul dry milk to the Port of Oakland as well as fuel stations and repair facilities. Large-animal veterinarians could see an increase in business, as would as ranch and veterinary supply companies.The plant, a development of Dairy Farmers of America and the DFA's Western Area Council, is scheduled to begin production in September 2013. Other service providers that could reap a windfall include restaurants, parts companies to supply the steel tubing and silos used in the plant's construction, companies …