Everyone with a head on his shoulders believes in the humane treatment of animals. But egg farmers and American consumers will soon face a choice between what's actually humane and what some animal rights radicals claim is humane. It may seem like a hair-splitting exercise, but the wrong choice will send American egg farmers the way of the telegraph operator.

In 2008 California voters passed Proposition 2, which, among other things, required egg farmers to build facilities by 2015 that allow laying hens to have more freedom of movement. And a newly signed California law expands this requirement to the 49 other states by requiring that all eggs sold in California come from producers who abide by Proposition 2 standards.

Is this good? Is it bad? It's unclear, because nobody can agree on what Proposition 2 actually means.

Egg farmers have one way of looking at it. One farm in Modesto just spent $3.2 million installing "enriched cages" to give its hens more room.

But America's wealthiest animal rights group, the Humane Society of the United States – not to be confused with your local pet shelter – sees things differently. HSUS, the main financial backer of Proposition 2, believes all California egg farmers – and out-of-staters who sell eggs in the Golden State – now must eliminate their cages.

So who's right – the farmers or the animal rights activists? And which solution is better for the hens?

The American Humane Certified program, run by the American Humane Association, took the position last month that enriched cages for egg-laying are indeed "humane." The legendary animal welfare activist Temple Grandin says these new cages are a big improvement. Enriched cages will be the standard in most of Europe by 2012.

The American Veterinary Medical Association also compares enriched cages with the free-range systems that HSUS wants. Judging them on various measures of animal welfare, it turns out that these cages offer several advantages, including lower rates of mortality and disease among the birds. Enriched cages also let hens express natural behaviors, just like HSUS seems to want.

In other words, it's hard to claim – scientifically, that is – that these newer cages are inhumane.

What's really at stake here is that word: "humane." HSUS seems to want a monopoly on it, even though other animal welfare-oriented groups – and plenty of scientists – disagree with its agenda. And that agenda is where the rubber meets the road: HSUS is run by vegans who don't believe anyone should eat eggs, regardless of how or where they were produced.

Most recently, HSUS has opposed attempts by California lawmakers to specifically define the standards mandated by Proposition 2. The very vague language that California voters approved in 2008 gives HSUS's enormous legal team enough wiggle room to hassle farmers who don't see things HSUS's way.

Of course, enriched chicken cages could be furnished with couches, Jacuzzis, treadmills and iPads, and activists who believe in "rights" for birds would still complain about them. HSUS is among them. And its vision of what's "humane" is outside the mainstream.

Since HSUS's view is that a vegan diet is the only "humane" way to eat, this whole "cage-free" egg campaign is a sideshow. It's a temporary step toward the group's larger goal.

If we embrace that goal, we're headed toward an America where "tofu scramble" and "eggless 'egg' salad" are our only options. And the first step toward pushing eggs – and other animal proteins – off the menu is hijacking the definition of "humane." Omelet and meringue lovers should learn to listen to scientists, not single-issue activists. The good news is that doing so actually elevates animal welfare and pushes the radical animal-rights ideology, not livestock farming, toward obsolescence.