“Eating Animals,” the new documentary based on Jonathan Safran Foer’s 2010 book of the same name, isn’t really about eating animals. It’s about the actual animals, before you eat them.

It’s a connection consumers have been encouraged not to make, as Bill Niman, a rancher closely associated with humanely raised meat, points out in the film. “The meat industry has done a good job in disconnecting eating meat from killing animals,” he says.

I think Niman is right, and it’s a good reason to watch the movie, despite its resolute one-sidedness. In fact, if resolute one-sidedness is a disqualifier for you, you won’t be watching many food documentaries. The genre exists for ax-grinding.

The ax has particular resonance here, as death looms large. Animals raised in CAFOs (concentrated animal feeding operations) are, of course, destined for the slaughterhouse, and the film looks not just at their death but everything connected to their lives: environmental impact, living conditions and the ramifications for farmers, consumers and agriculture as a whole.

It’s a long list, on an important topic, and though the movie, directed by Christopher Quinn, with narration by Natalie Portman, has its share of inaccuracies and omissions, there’s value in showing consumers the dark underbelly of animal agriculture.

What the film gets right

There’s one big important thing that’s true, and it’s the film’s reason for being: Many of the animals we eat lead pretty miserable lives, and we should be paying attention. How many and how miserable? Hard to say. But, by comparing some of the worst cases with some of the best, the movie at least gives us an idea of the spectrum.

The best case are the farms where animals live outside and farmers talk about stewardship and welfare, and I suspect that livestock, given the choice, would pick Bill Niman or Frank Reese or Paul Willis, all farmers profiled in the film, to live with.

The worst case is brought vividly home by stomach-churning undercover videos from farms and slaughterhouses, as well as scenes from the chicken farm of Craig Watts, a former grower for Perdue Farms who went public several years ago with his contention that the Perdue contract forced him into a cycle of debt and required him to participate in a system that is inherently inhumane. And conditions at his farm sure don’t look good.

It’s certainly true that broiler chickens are raised in barns where they get a bit less than one square foot per bird, and they generally don’t see the light of day. They’ve been bred to grow so fast that their bodies don’t support them very well. That makes them susceptible to a host of problems including metabolic disorders, leg injuries and skin lesions (from lying down, which they do much of the time). Industry-wide, four out of every 100 will die before they reach market weight; if you’ve got 30,000 chickens in a barn, and they grow for seven weeks, you’re cleaning out 25 carcasses every day. And, as Watts points out, at least some contracts between chicken farmers and the big chicken companies base part of their compensation on “performance relative to other farmers,” according to Tom Super of the National Chicken Council.

Also true is the fact that animal agriculture is a major contributor to global warming. Bruce Friedrich, co-founder of the Good Food Institute, a nonprofit dedicated to improving the food system, says it’s responsible for somewhere between 14 percent and over half of climate change, which is technically true since most responsible estimates seem to hover in the 14 percent range.

Animal agriculture is also a factor in the problem of antibiotic-resistant bacteria in humans, thanks to the heavy use of the drugs on farms. Manure from hog farms does lead to nutrient runoff into waterways (although generally not from lagoon leaks, as the film implies, but once the manure is spread on crops as fertilizer).

Some of the most fundamental pieces of the film are true — as far as they go. The biggest problem is what’s not in the film. Which brings us to . . .

What the film gets wrong

There are some flat-out falsehoods. Chickens aren’t genetically engineered. (They’ve been conventionally bred to this fast-growing, injury-prone incarnation.) There isn’t pus in milk. (There are white blood cells, which aren’t the same thing.) And Portman’s narration is overwrought and misleading. (I dare you to tell a group of farmers that they’re “peasants serving the will of corporations.”)

The biggest problem with the film, though, isn’t the wrong things that are in it. It’s the things that aren’t in it at all.

The most obvious — and telling — absence is of anyone who disagrees with the filmmakers about CAFOs. With one exception — a brief appearance by Temple Grandin, a well-known animal scientist who specializes in designing humane slaughterhouses — they don’t interview animal scientists who work with confined animals, or any of the farmers running those farms responsibly and with a commitment to animal well-being, or any of the large companies that design and administer the systems in which pigs and chickens are raised.

If they had included that perspective, here’s what they probably would have heard: Confinement systems protect animals from predators and injury (true). Raising animals efficiently makes meat, eggs and dairy affordable for everyone (true). Healthy animals grow best and are profitable, so farmers have an incentive to protect animal health (true). Most farmers are committed to animal welfare, and those horrible videos are just the bad apples (absolutely no way of knowing).

Those scientists will also tell you that any assessment of animal welfare needs to be “science-based,” and they will show you the statistics about injury, predation and mortality. Maybe even stress hormone levels and play behavior. They might use the word “anthropomorphizing” to label what the filmmakers, and people who agree with them, are doing.

Problem is, this takes us back to what the film gets right. Science doesn’t give us many tools to measure animal well-being, and sometimes we have to rely on what we learn when we spend time with them. I’ve raised meat chickens, laying hens and pigs, and it’s not that hard to figure out what they want. What’s hard is developing metrics that can rigorously assess animal well-being. Meanwhile, we have to bumble through best we can.

The film’s basic contention is that animals shouldn’t be kept indoors. While it’s certainly possible to have a pretty good confinement system (I’ve seen them) or a crappy outdoor farm (I’ve seen them, too), there’s an easy way to find out whether animals want to go out: Open the door.

Should you see it?

If you’re familiar with the way we raise animals, you can pass; the movie doesn’t break any new ground. If you’re unfamiliar, it’s probably worth seeing, as long as you keep in mind that what you’re seeing are the worst cases, and we don’t know how prevalent they are. The film opened in New York and Los Angeles on June 15 and rolls out to the rest of the country over the next few weeks. It comes to the District on June 22.

The best line in the movie is Grandin’s. She comments on what are called “ag-gag” laws — statutes that criminalize taking pictures at animal facilities. “Ag gag is the stupidest thing ag ever did,” she says. “When you get bashed, you should be opening the door, not closing it.”

Again with the door-opening. Maybe that’s the theme here. There’s a case for not letting the animals out, but it’s hard to see why you shouldn’t let the people in. As long as that’s not happening, “Eating Animals” plays an important role.

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