by Marion Nestle
Sep 10 2007

Today’s Question: Feed Efficiency

I haven’t thought carefully about this question since I first read Francis Moore Lappe’s Diet for a Small Planet in the 1970s: “I have a question…about growing grains for livestock feeding: When corn, for example, is grown, it has a k/cal value, or an amount of caloric energy that I assume can be counted for human nutrition. As it is used for feed, is caloric energy lost in the transfer? In other words, is the resulting food (all the butchered and eaten parts of a cow, for example) similar in energy content to the edible feed that went into it? I assume we lose some caloric value along the way, but how much? To me, this has all kinds of implications that I’d like to ponder, including the implications of this from the (admittedly broad) prospective of global hunger.”

This is about “feed efficiency ratios”–the amount of food it takes to make a pound of animal or a pound of us. Let’s hear it for Wikipedia, which has a nice summary with a reasonable reference. It takes more grain to make beef than pigs, chicken, or fish. A lot of those animals are not usable for food (maybe half a beef carcass, for example) and we have our own problems with efficiency. The calories listed in food tables are pretty much what we can use and the better tables specify how well the meat is trimmed. Good question!

  • Jane

    It takes zero corn to feed a cow. Cows are supposed to eat grass, grass, and nothing but! American farmers are basically paid to feed corn instead, at the expense of our health.

  • I wonder if that example on Wikipedia is assuming the cattle are fed grass or if they use the more likely corn feed such that they are fed on the horrible and too common factory farms. When cows are fed corn the majority of it must be transported in–possibly from far away farms. We have to count the transportation costs of corn, the production and spreading of pesticides and chemical fertilizers, and the production/transport of antibiotics since these herbivores don’t naturally eat corn and this feeding practice makes them sick. A great deal of energy–fossil fuels or kcals go into growing cattle on factory farms.

  • Excellent points. Let Wikipedia know.

  • I’m with Jane on this one. The kcalorie efficiency is a moot point. That argument against eating meat because of all the grain/energy the animals consume *only* makes sense *if* the cattle are fed an unnatural diet of grain. It doesn’t have to be that way. Cattle/cows should be pastured, then they are perfect solar energy converters, making protein from grass (that humans can’t consume). Where cattle are ill-suited due to climate, topography, etc., sheep, goats, buffalo and game are good alternatives.

  • Bix

    Since we’re talking about feeding the planet, it has been eating at me … how do we provide free-range meat to the world’s 6.6 billion population, a number expected to grow by 2.6 billion in the next 44 years alone? When at least 40% of us currently live on 2 dollars a day?

    Even just looking at the 300 million people that live in the US. Is it possible to convert to a system of pasturing livestock (from a system of factory farming livestock) that can efficiently feed everyone? At a reasonable cost?

  • Jane

    Here’s a thought.

    What if the roughly $20 billion in farm subsidies currently directed at grain farmers got redirected to pasture farmers and growers of organic fruits and vegetables instead? The prices would surely go down. Or even redirect those funds, in the form of lowered taxes back to the taxpayer so he/she would have more ready cash for purchasing the more expensive pastured food?

  • Jane

    And of course the land currently used for growing grains would be converted to rich pasturelands over time. It takes time to heal land that has been abused, but it must be done for our health and our planet.

  • Jane

    The reason pastured food is more expensive than cheap grain-based food is because they receive no government subsidies. Why not level the playing field and let all growers of food compete with each other fairly? Properly managed pasture farming requires little input from outside sources. What could be cheaper to do?

    I’ll get off my soapbox now.

  • Bix–

    Well, for one thing, we could stop eating around 1/2 a pound of meat every day. This is an absurd amount of meat for anyone to eat, far in excess of what is needed for a healthy diet. Of course, no meat is *needed* for a healthy diet, but if one enjoys eating it and has no competing ethical issues, that’s fine. But there is no call for expecting to have meat at every (or nearly) every meal. Once or twice a week should be sufficient for anyone. That all by itself would reduce the problem greatly.

  • Absurd is in the eye of the beholder. I think some people eat an absurd amount of sugar and starch and not nearly enough meat, particularly from pastured animals. Meat is very dense in nutrients and sustains the body quite well compared to vegetarian foods, ounce for ounce.

    If one can’t eat grains, beans, and other starchy foods because they raise blood sugars too high (diabetic), soy because it is toxic to the thyroid (in addition to other unhealthy aspects of soy, then there isn’t much left except animal-derived foods and produce. Fish is getting dicey because of unsustainable fishing practices that damage the environment, over-fishing, heavy metal and PCB contamination, etc. So that leaves dairy, eggs, meat, poultry, and game (preferably pastured), and nuts for good sources of protein. Oh I suppose we could even throw in insects for protein, too, as some cultures rely on them. One would have to eat like a cow (all day), grazing to get even barely enough protein from veggies and fruit, and it wouldn’t be high quality complete protein. Meat once or twice a week might be an option for some, but that’s not optimal for most, especially long-term, unless dairy and eggs are also eaten in sufficient quantity.

    There is an argument that the increasing trend toward *vegetarian eating* is actually *harming the environment* at an increasing rate, increasing the amount of acreage for vegetable crops that is tilled up for monoculture, especially in industrial managmeent practices and scale, which increases pest problems, soil depletion and erosion, etc. Monocropping is particularly unnatural, as it upsets the delicate balance in the ecosystem, requiring additional imput in order to maintain productivity. Organic or conventional is not the issue in this perspective.

  • Bix

    **”The reason pastured food is more expensive than cheap grain-based food is because they receive no government subsidies. Why not level the playing field and let all growers of food compete with each other fairly?”**

    I understand subsidies somewhat (I’m not an economist! 🙂 And I’ve been mulling this over. Especially in a context of feeding everyone.

    Would the members of the WTO allow the US to subsidize thousands (millions?) of small farmers who raise free-range livestock? And sell at reduced prices? I think this could only be accomplished on a global scale. Subsidies would have to be paid (who would pay?) to farmers in Brazil and African nations, and Japan, etc., at equivalent levels.

    For as much as I, as a citizen of the US, desire my government to transfer some of its financial support away from grain and towards fruit/veg (and maybe pasturing), it has been the World Trade Organization that has had more pull. Brazil was successful in its recent complaint to the WTO that the US was subsidizing its cotton growers too much, and affecting world prices. The WTO’s subsequent ruling will probably reduce cotton subsidies in this country.

    I think a level playing field is a good idea! But I think for this to work, the field we need to level will have to extend worldwide.

  • Bix

    Interesting last point there, Anna.

    I guess some of the “organic” foods I buy are monocropped. Now I don’t know which direction to lean …. towards “organic”? or “local”? or “raised in small fields using crop rotation and other sustainable practices”? (is that the opposite of monocropping?)

    And then, getting back to feeding the planet. Can we change growing practices worldwide so that the planet’s population can have access to organic, local, sustainably raised food? It’s certainly a goal! But the more I think about it, the more daunting it seems.