Elsie the Cow would never have believed it: Computers are taking over the dairy industry.

Now, don't fret, Elsie. They still need cows for the raw product. But at the Embassy Dairy Plant in Waldorf, Md. computers do the rest. Milk pours through the plant's computer system at the rate of 65,000 gallons a day, and there is not a cow in sight.

Embassy, now in its third year of operation, is one of only four completely computerized dairy plants in the nation. During a recent tour for reporters and representatives of the Dairy Industry Council of Greater Metropolitan Washington, plant officials described how the operation works.

"We try to process milk in as partical and economical a way as possible," said engineer Joseph W. Nisonger. "And this computer system has really helped us."

The plant produces only fluid milk products, but it produces them in abundance. It currently processes one million gallons of milk per month, running 12 hours a day five days a week. Future plans call for doubling that production over the next five years with only minor equipment changes.

The process begins with the arrival of raw milk from area dairy farms. The milk is transported to Embassy in tank trucks that are double walled to protect the freshness of the product. The milk is then weighed and tested and, if acceptable, unloaded into one of three 30.000-gallon refrigerated silos.

The computer takes it from there. The processing system is controlled by a mini-computer system. In an elaborate control room, the computer monitors the amount and location of milk in the plant and controls all the pasteurizing, homogenizing, cooling, blending and piping of milk.

Then the milk is ready for packaging in one of eight machines that yield products ranging in size from six-gallon bags to half-pint containers. A far cry from the days of the bucket and pail, one of these assembly line contraptions produces 210 half-pints a minute.

Embassy's plant is immaculate. Allof the employes wear white uniforms that would never do on a farm but do just fine here. "Everything's so clean and shiny at this place," said dairy farmer. Arthur Johnson of the Capitol Milk Producers Association.

The computer still can't do everything, however. Workers are needed to man the controls, to work on the assembly lines and to load the 40.000 to 70.000 gallons of processed milk that leave the plant each day.

Among those on the tour was Wendell S. Arbuckle, professor emeritus of dairy science at the University of Maryland and a scholar on the science of ice cream making.Arbuckle said he has brought visitors from foreign countries to see the Embassy plant because it is "so well arranged and well engineered. It's a model plant and surely the way of the future in this industry."

After the tour, participants became guinea pigs of a sort, tasting several milk by-products such as frozen yogurt and sterile milk. The group also sampled sweet acidophilus milk, a special lowfat drink that contains bacteria beneficial to the human intestinal tract. Dairy industry representatives were touting it as a product to watch for the future.

"We've come a long way since the days of the small farm some 30 or 40 years ago." Arbuckle said. "We're moving out into all sorts of new directions. It's kind of exciting."

But as the gathering dispersed at Embassy's sprawling 25-acre site, one nagging question remained: Where are the cows?