Over at the New York Times, James E. McWilliams, back on April 12th 2012, published an op-ed piece called The Myth of Sustainable Meat. It's an attack on the idea that meat can be raised under better conditions than the farm-feedlot system currenty used in the industrial world. This was a direct attack on the techniques employed by Joel Salatin at Polyface Farm--and Mr. Salatin was justifiably upset. And he fired back.
|from the Polyface Farm website|
But the Salatin / McWillliams feud raises interesting questions. For example, Mr. McWilliams claims "Grass-grazing cows emit considerably more methane than grain-fed cows"Mr. Salatin responds: "[The claim] that grass grazing cows emit more methane than grain-fed. This is factually false. Actually, the amount of methane emitted by fermentation is the same whether it occurs in the cow or outside. Whether the feed is eaten by an herbivore or left to rot on its own, the methane generated is identical."
There's a lot going on here. The definition of "considerably" for one. But overall, it seems that Mr. Salatin may be mistaken insofar as the amount of methane production from dairy cattle appears to be reduced when they are fed a diet higher in dietary fat composed of crushed oilseeds (sunflower seed, canola seed or flaxseed). Agriculture Canada also reports "Adding more grain in the ration also reduced methane emissions, but the scope for increasing the amount of grain fed to ruminants is fairly limited as this ignores the importance of ruminants in converting fibrous feeds, unsuitable for direct human consumption, to the high quality protein sources milk and meat." But it's not just grains: Ag Canada continues:
Diets based on corn grain, compared with barley grain, reduce methane emissions, as does feeding high quality forages such as corn silage and alfalfa. Ionophores, antimicrobials that target the ruminal bacterial population and increase production efficiency, also reduce methane emissions at least for a short time.This outcome has been replicated in several other similar studies such as the Australian one reported by Discovery:
[...]a new study of the Australian livestock industry finds that the seemingly greener alternative to grain-fed beef -- beef from cows grazed on grass -- produces more greenhouse gases per pound than beef from feedlots.But does this take the sting off eating CAFO meat? Well, not so fast. Discovery reports the Australian study's lead author, Matthias Schultz, saying:
"The reason for that is that, on the one hand, the grain-based diet can be digested better by the animals, so that reduces the enteric methane production by the animals," said study lead author Matthias Schulz of the University of New South Wales Water Research Center in Australia.
"[...] although the (total) emissions are higher on the feedlot, the animals gain weight quicker," Schulz said, so the animals are slaughtered sooner, emitting less gas overall. "On a per-kilogram-of-meat basis, the feedlot performs better."But as Ag Canada remarks, when it comes to converting fibrous material not suitable for human consumption into high-quality foodstuffs, cattle rule. Grains are very edible by people, grass not so much.
And there is a lot of uncertainty as to how this will play out in real-world examples. Ag Canada claims improvement of 5-20 percent under controlled conditions. And this only takes into account GHG emissions--specifically methane. If that's the only marker, stop eating beef today, and replace it with lamb and mutton. Either of which contribute half as much methane to the atmosphere--mostly because their average lifespan is only half that of cattle.
Cattle are also generally started on grass and finished in a CAFO--they don't spend their whole life there (unlike pigs). Cattle spend about six weeks in a feedlot, so the transition to grain doesn't save that much methane production. In addition, cattle are only kept for six weeks because the all-grain (primarily corn) diet is not good for them; they develop ulcers in their rumen, leading to e. coli contamination.
The studies I've seen also don't try to account for a product life-cycle GHG footprint. All that grain comes from somewhere, and that somewhere is usually soaked in hydrocarbons, and the grain is planted, harvested and transported by hydrocarbons. There still may be a savings in GHG emissions, because methane is so much more potent a GHG than CO2, but the accounting still hasn't been done.So Mr. Salatin may yet be correct.
But this does raise the issue of what do you trust when it comes to food? This question was relatively easy. It took me a couple of hours to find the appropriate studies, read and digest them (few GHGs produced) and then write this post. This isn't always the case. Questions like comparing organic and industrial farming techniques are much more difficult to sort out. Too often you're not just comparing apples and oranges, you're comparing apples and ICBMs. I've been involved in food security issues as a consumer, a producer, and a writer for most of my life, and I have very few hard and fast rules about the whole topic. I know that local organic agriculture generally doesn't lead to a Silent Spring (viz. Rachel Carson). Local agriculture is generally to be favoured over imports, for a lot of reasons, not just their environmental impacts. I'm learning that there is actual data to back up my gut feeling that small is better than large (I've pointed at Fatma Unal's paper more times than I can count). But other than that, there's not a lot that fixed. Are you better off not eating meat at all? Well, that depends.... Are you not eating meat for environmental reasons? There's some significant evidence that farms are better off raising some ruminants. Health reasons? I don't eat beef since the vCJD (Variant Creutzfeldt-Jakob disease) concerns in the '90s and the Alberta government's refusal to allow testing of every animal. And, of course, the whole CAFO issue--I try to avoid CAFO meat of any type. But to stop eating meat and replace it with what is probably the most industrial, processed, product around, soy, just seems crazy.
So who do I trust? Pretty much no-one and nothing. I put much more faith in books than internet articles, but give me a sourced blogpost over an unsourced book any day. I'd rather read the study than the newspaper article. I'd rather have to follow an issue for months than read one article and think "Right. That's settled."
Ben Goldacre is a doctor from the UK who writes, in books like Bad Science: Quacks, Hacks, and Big Pharma Flacks, about how badly managed drug studies are. The same issues can be raised around food -related studies. Who did the study? Who financed it? Are negative results being reported as they should be, or are they suppressed? Are the studies conclusion supportable, or are they only applicable to a limited circumstance?
It's a tricky business, particularly since the Monsantos and Cargills of the world have learned from Big Tobacco how to obfuscate, divert, and flat-out lie about what they're doing and the results of that. But that's for another day.