KENNEWICK — Washington dairy farms have been able to grow, thanks to exports.

The state has seen the value of dairy exports increase by 35 percent during the past three years, reaching $461.2 million in 2011, according to the Washington State Department of Agriculture.

That makes foreign countries a critical market for the milk that Bill Wavrin’s 3,800 cows produce.

Wavrin, who owns Sunny Dene Ranch near Mabton with his brother Sid Wavrin, said Darigold takes their milk to where it is needed most.

Bill Wavrin said the industry has improved equipment, cattle care and nutrition, which means the amount of milk cows produce has increased, and now, on average, a cow produces about 10 gallons of milk a day, he said.

More than 20 years ago, dairy farmers may have gotten 5 to 6 gallons of milk from a cow in a day, according to the Washington State Dairy Products Commission.

Bill Wavrin said his cows are milked twice a day, with the milking barns busy for about 20 hours each day. That keeps about 45 employees busy.

The Yakima Valley is one of the largest dairy-producing areas in the nation, according to the Washington State Dairy Products Commission. Benton, Franklin, Klickitat and Yakima counties have 91 dairies and more than 110,000 cows.

The amount of milk produced by Washington cows grew by almost 11 percent, from about 5.6 million pounds in 2009 to about 6.2 million pounds in 2011, according to the Washington State Dairy Products Commission.

Washington is the nation’s second largest exporter of dairy products, after California, according to the state. But when it comes to the amount of milk produced, Washington holds the last spot on the nation’s top 10 list, according to the U.S. Department of Agriculture.

Darigold has expanded its exports consistently since it began shipping products overseas more than 30 years ago, said Dermot Carey, Darigold’s senior vice president of ingredients. Darigold is owned by the Northwest Dairy Association, a co-op representing about 85 percent of the dairy farmers in Washington.

At the Sunnyside Darigold plant, about 5 million pounds of milk is processed into cheese, dry whey powder and whey protein concentrate each day, Carey said. That milk comes from Eastern Washington dairies and is enough to fill 70 tankers.

The Sunnyside Darigold plant made up about 33 percent of 300 million pounds of milk Darigold exported in 2012, Carey said. More than 17 percent of the cheese and 72 percent of the dry whey made by the 140 or so employees in Sunnyside last year were sold overseas.

“The new growth in dairy consumption is occurring in emerging economies where dairy production cannot grow due to climate or infrastructure issues,” Carey said. “Here in the U.S., consumption is not growing as fast as dairy production, hence we need the export demand to sustain a viable industry here at home.”

Skim milk powder exports to Southeast Asia is the largest export market for Darigold, Carey said. The economic growth experienced in countries such as China has fueled dairy consumption.

While Darigold is the largest exporter of U.S. cheese to Japan, China imports U.S. powder milk, according to the Washington State Dairy Products Commission. South Korea has become the fastest growing cheese market, thanks to the popularity of pizza.

Southeast Asian countries are building new dairy plants but lack the milk to fill them, so they import U.S. dairy products, according to the commission.

Nationwide, milk production is up 17 percent, a gain of almost 30 billion pounds since 2003. More than 60 percent of the added milk production has been exported, according to the U.S. Dairy Export Council.

The U.S. is in good shape to compete because of the food safety standards dairies are already required to meet, Wavrin said. It’s uncommon for a foreign country to have higher food standards.

And Washington’s position near ports sets up the state’s export market to grow with foreign economies, said Janet Leister, general manager of the Washington State Dairy Products Commission.

Agriculture has been a big contributor to the economy, with the exports from the overall industry particularly helping during the recession, Leister said. Dairy, as the state’s second highest valued commodity after apples, has been a large part of that, she said.

In 2011, the state’s milk production was valued at $1.3 billion, about 34 percent above 2010’s value, according to the state.

Agriculture could replace some domestic business with exports, so while the recession was felt, it wasn’t as hard as it was in other industries, Wavrin said.