When the National Zoo has rare animals to breed, it dispatches them to the Zoo's 3,300-acre retreat in the foothills of the Blue Ridge 60 miles west of Washington. There, in sylvan splendor, herds of exotic fauna from reindeer to sable antelope are free to go forth and multiply.

That's the good news.

The bad news is the common white-tailed American deer population trapped inside the preserve's 8-foot fences has been multiplying, too, feasting on the zoo's alfalfa crop and spreading parasites to zoo herds. So the Zoo consulted the Virginia game commission and organized a 2 1/2 week bow and rifle hunt to thin the 650-head herd.

"We never say shooting, please don't say shooting. Taking the deer is what we're doing," said Robert Hoag, Zoo spokesman said yesterday. "We don't like the idea of taking the life of any animals, but we really don't have any other option if we're going to cut down disease."

Whatever you call it, prospect of killing as many as 200 deer this November has the wildlife protectors angry.

"It's an abomination, horrid," said John W. Grandy, a biologist for the Humane Society of the United States. ". . . To hunt deer which are by all accounts tame with bows and arrows. We can't discern that there's really any reason for it. . . This is just a fiasco."

"Bows and arrows are incredibly cruel," agrees Lewis Regenstein, vice president of The Fund for Animals. "The animals die a quiet hell, and you get the same amount crippled as you do killed. I think it's highly improper for the National Zoo, which is a protector of animals, to be promoting an event of torture."

The hunt, however, won't be the first at the preserve near Front Royal, Va. Last year, the zoo granted permits to about 400 hunters, who brought down 124 deer during a similar period. That was close to the 35 percent herd reduction zoo biologists said was necessary if starvation and further destruction of forest was to be avoided. The herd having replenished itself, that's the same problem that zoo officals say they face this fall.

The alfalfa crop, upon which the zoo relies to feed herbivores back on Connecticut Avenue, had been routinely demolished by deer until the hunt was begun last year. This year the harvest was 10 tons.

Wildlife defenders said yesterday they will appeal to the Smithsonian Institution, which oversees the Zoo. "I wonder what the Smithsonian's congressional supporters are going to think about this?" asked the Humane Society's Grandy.

Zoo officials, meanwhile, were chalking this one up to misguided anthropomorphism.

"Many urban people don't realize deer give birth to twins," said Jack Williams, an engineer who lives on the preserve. "We've had a 75 to 150 percent increase in the deer population here. They devour our farm crops, the alfalfa we try to raise to feed our animals. They've also destroyed everything around my house in the way of ivy, rhododendrens, azalea bushes. The hunting won't reduce the population below a safe level."

Shooing the deer out of the preserve has been tried, zoo officials say, but with no success. "Deer don't herd like cattle," says Virginia game official Jack W. Raybourne, the man who has advised the zoo staff on the hunt.

"If they had a problem with deer they had all summer to take care of it," counters Grandy. "They could have opened the gates and chased some out, they could have set up large traps, done the trapping and herding slowly, over time."

Grandy and others say that instead of strengthening the herd, the hunt will have the opposite effect. Hunters will go after and are most likely to bag the healthiest, most aggressive bucks in the herd.

"Well, that's a true statement," said the state game commission's Raybourne, "but unfortunately, natural selection doesn't work fast enough."

The hunt may be cruel, he said, "but it beats starvation all to pieces. There are no old age homes for animals. Animals don't just get old and curl up on the leaves to die. It's the fang or the claw, starvation or disease."

Sabin Robbins, executive director of the Friends of the National Zoo, waxed philosophical. "When you look at the other options, trapping, etc., hunting is a difficult but responsible decision. People don't object to snake hunts. But as the animals get larger, warmer and furrier, people get less and less rational."