Robert Kay has a new twist to the old riddle about the chicken and the egg. As chief executive of Origen Therapeutics in Burlingame, Kay knows that birds begin life as embryos, and he hopes to parlay that knowledge into a technique that could change the future of chicken-kind.

For those whose familiarity with fowl husbandry comes from the new claymation movie "Chicken Run," an overview of the chicken industry is the prerequisite for appreciating the boldness of Kay's plans.

Let's start with the numbers. Each year, Kay said, Americans consume some 10 billion chickens. When the rest of the world gets factored in, the annual appetite hits 38 billion birds.

To achieve these volumes, chicken production has become a specialized industry that begins with the Big Three — two breeding firms in the United States and a third in Britain. Between them, they breed billions of chicks that they sell to the farmers who raise them into the birds we eat.

For the really big farms, the ones that raise 50 million birds a year, time is money. They try to grow their flocks from chick size to market size — which is about 4.5 pounds — as quickly as possible to minimize their main costs of providing feed and removing waste.

Thus the Big Three have focused on breeding birds that fatten up in as little as 42 days. And they strive to continue bringing that number down by developing breeds that bulk up faster.

According to Kay, however, traditional breeding techniques are starting to hit some limits. For instance, when breeders select birds that grow fatter faster, these birds tend to be duds at laying eggs. Meat industry breeders aren't interested in eggs as products. But they do need to make sure that their meat birds can lay enough eggs to create flocks large enough to serve the 38 billion-bird market.

So the breeders must compromise, Kay said, making sure their newest meat birds retain some egg-laying skills, even though this might mean a sacrifice in their time-to-market traits.

But what if there was a way to have the best of both worlds, to create a breed that reached market weight in record time, but also had a high egg-laying potential, so breeders could quickly supply farmers with billions of these new super-birds?

That is where biotechnology comes in.

Return, for a moment, to the fertilized chicken egg. Imagine peering through the shell, past the egg white to the tiny embryo, about the size of a match head, that floats on the yellow yolk.

In laboratory experiments, Robert Etches, Origen's chief scientist, has removed embryonic cells from one breed of chicken and injected them into the embryo of a different breed. The process is akin to cloning.

When this experimental technique works — which Origen says is about one out of 10 tries — the result is a chicken that gets many of its traits from the injected embryo.

So far, the company has focused on showing visible traits, such as feather color. It is trying to boost its success rate, especially in assuring that the desired trait — fast weight gain — ends up being dominant.

Experimental though it may be, Kay thinks this technique can eliminate the compromise between fast egg laying and fast meat growth. Say breeders had their best laying hens lay billions of eggs, creating huge flocks in record time. Of course, left alone the eggs from these hens would create scrawny chickens that were good at laying eggs but lousy at making meat.

But Origen wouldn't leave those eggs alone. It would inject the eggs with embryonic tissue from birds bred to maximize meat production, at the expense of egg laying ability. Chickens would be specialized as never before. The layers would do all the laying, and biotech would come in at the factory level to zap all those billions of eggs with embryonic tissue from the best meat-growers that science could devise.

Remember, the whole idea of meat production is to get the time from chick to market weight down from 42 days to as brief a time as technically feasible. Kay thinks this technique could do just that.

"And how are we going to do this on a billion-bird scale?" Kay said, anticipating my question.

It turns out that a North Carolina firm, Embrex Inc., is already injecting vaccines into billions of chicken eggs annually, to inoculate the birds against diseases that might otherwise decimate flocks and cripple production. (See the process at www.embrex.com).

Last month, Origen and Embrex announced an agreement to co-develop Kay's high-tech chicken breeding process. Origen will provide the biotech know-how, and Embrex will contribute the industrial injection smarts.

Even Kay, who has to be optimistic, thinks it will take three to five years to solve the myriad technical challenges ahead, not the least of which is making sure that the needles hit the embryos, unerringly, 30 or 40 billion times a year.

Whether Kay succeeds or fails, the larger point is that every aspect of food production is moving in the same direction, pushing the limits of traditional breeding by using a variety of genetic engineering techniques.

Wary of the controversy around genetically engineered foods, Kay emphasized that his process would not add any non-chicken genes. He simply hopes to clone the ideal meat chick on an industrial scale.

"We plan to make full disclosure on a label to let the consumer decide," Kay said, aware that his plans will make some people uneasy.

And no wonder. The bioengineered corn on the market today sounds tame alongside the foods on the drawing board; salmon and tomatoes genetically tweaked to grow large; eggs bioengineered to lessen artery-clogging cholesterols; rice altered at the genetic level to address vitamin deficiencies.

Some of these may be good ideas, and others bad. But I feel uneasy about the fact that a breed of hairless apes, not all that far removed from the days when their kind dined on wooly mammoths and wild berries, now wields an exponentially increasing power to hack into the genetic code, to superimpose its profit needs on 4 billion years of nature's handiwork.

Yet I don't see the alternative. Oh, I could quit barbecuing chicken, but I don't think that would solve the underlying problem that your modern Homo Sapiens want their bellies filled, cheaply and conveniently, and would resist the sort of social reengineering it would take to migrate them from their comfortable city jobs to the chore-filled green acres.

In fact, the more I think about it, the more I wonder which side of the barbed wire we're on in this Chicken Run world.