There is an entire spectrum of opposition to animal agriculture.

The attacks include welfare and handling issues, nutritional dangers, environmental threats and the card the most determined vegans always play: the death of a sentient creature.

All sorts of peripheral issues about corporate control, microbial contamination and the use of antibiotics and hormones typically get temporary traction in the media. But after a recall is complete, or some study’s publicity has run its course, those issues fade from public consciousness.

What persists on both the media and consumers’ radar, however, are concerns about the business of slaughtering food animals. Yes, ecological impact is ascendant among the most vocal activists of late, but ask a vegetarian what first prompted his or her “conversion” to a meat-free lifestyle, and the response is more often than not related to the “horrors” of killing cows or pigs.

The supposed ecological destruction wrought by livestock producers then becomes after-the-fact justification, not the reason, for making a dietary change.

It’s like buying a car: We decide on the model and color based on an emotional reaction to how it looks on the lot and how it feels on the road. Then, we justify the sticker shock by calculating gas mileage, mechanical reliability and the ultimate resale value.

The key factor is how we feel, and that’s also true of vegetarians’ conversion: It’s how they feel about killing a sentient being that’s the animating factor in embracing the philosophy that no animal should ever die to sustain some other animal.

Of course, after the Road to Damascus moment, it sure helps that the advances of modern food science and the existence of a sophisticated processing and distribution infrastructure allows us 21st century consumers to pick and choose among an incredible array of formulated vegetarian foods made with plant proteins and tropical ingredients unavailable (and unknown) to previous generations.

How Nature Really Works

Here’s the problem with the “No Animal Killed for Food” philosophy. In Nature, killing for food isn’t a discretionary activity — for every creature in existence, it’s a way of life.

So to speak.

For instance: How about the big cats, the iconic lions, tigers, leopards, cougars, jaguars, and cheetahs that headline so many Save the Wildlife campaigns? Lions hunt and kill (viciously) all kinds of interesting, sentient, even loveable animals: Zebras, giraffes, baby elephants and hippos, not to mention pretty much every African antelope species — kudus, gazelles, impalas, springboks. You name ’em, lions will kill ’em.

Or how about an animal that has acquired celebrity status, albeit in captivity? The orca is a true apex predator that relentlessly kills an array of marine mammals: Seals, sea lions, otters, dolphins, even baby minke and gray whales.

Or how about a species that has endured centuries of hatred and hunting? Wolves, particularly the North American gray wolf, is a cunning, opportunistic killer that will feed on mice and birds, if need be, but which prefers to hunt down elk, deer, moose, caribou, antelope and even bison whenever possible. And the younger and weaker members of those species will die a slow and painful death, as exhaustion and the loss of blood from dozens of wolf bites eventually take their toll.

The supposition that vegetarian activists put forth goes like this: Wildlife get to live a “natural” life — before getting their throats ripped out or their heads bitten off — so their wholesale slaughter is perfectly normal and natural.

Yet if farmers simply let their livestock — or companion animals, for that matter — simply roam at will, the resulting mortality by predators would land them in court on charges of abuse.

Now, I know the veggie argument is that humans are now so advanced, so intelligent, that we no longer need to consume animal foods. We can simply substitute soybeans and salads for the meat and dairy that have sustained humanity for eons.

Of course, that effectively divorces us from the rest of Nature. Yet on all of the eco-issues about which activists are equally adamant, the meme is “You Can’t Fool Mother Nature.”

Except when it comes to the single most important human activity: Food production.

When it comes to nourishment, we can (and should) exist in a world where our sustenance is manufactured, formulated, processed and altered so far from Nature that virtually everything veggies are eating these days would be unrecognizable to people a few generations ago.

It’s about time to point out that the vegetarian lifestyle requires something that no eco-activist should ever embrace.

Factory foods.

The opinions expressed in this commentary are solely those of Dan Murphy, a veteran food-industry journalist and commentator.