Tuesday, March 21, 2006

Warning! All vegetarians might like to move on to the posting above or below this one now - this is for meat eaters only!

For those of us who like our protein in concentrated easy to digest portions - and that's an ever more rapidly growing constituency - crunch time (or was that lunchtime) is here. In the West animal feed technologies and animal husbandry practices mean that for every 2.5 kg of plant proteins we feed to our livestock (we are talking beef here), we get 1kg of high quality protein for human consumption. A lot of what the livestock is eating is made up of proteins and other nutrients that wouldn't available to us if they didn't process it for us first (not without a lot of mechanical or chemical processing, and who wants that?). The amount of vegetable protein verses the resulting meat protein is called the conversion ratio i.e. 2.5:1.

The crunch comes where it almost always does these days and that's from developing nations. As affluence has spread so has meat consumption; however, the typical conversion ratio in developing countries is around 8.5:1! To put this into perspective, if all of us were to eat the same amount of meat as the average person from a developed country but grown at a developing country's conversion rates, nearly third of the Earth's land surface would need to be put over the production animal feed stuffs.

We need to 'grasp the nettle' and come up with an equitable solution that will allow us to 'have our c(ste)ak(e) and eat it'. Maybe GMOs are the way to go (higher yields, more protein), or maybe its technology transfer (show developing countries how to do more with less). Any ideas?

(And for all those NEO-CONS out there - 'leaving it to market forces' is how we got into this mess in the first place).


At 6:29 pm, Blogger Matt Burge said...

Is it not the case that technology transfer is happening much quicker these days and therefore, as a bigger middle class in developing countries affords more meat, their business folk can also afford to purchase the better technology, helping to get the ratio down.

At 9:48 am, Blogger Pete Smith said...

Well it sounds pretty scary. But I found myself wondering why cattle in "The West" are over 3 times more efficient at converting protein that those in developing countries. Even allowing for selective breeding of specialised breeds for beef and dairy, they're still cows. I would really like to see where you got your figures from; I'm not convinced by your "conversion ratio" expressed as protein in/protein out. Conventionally, the conversion ratio represents the efficiency of converting the WEIGHT of food intake into animal body WEIGHT. The cow is the least efficient animal at performing this conversion, with 1Kg of body weight requiring 7-10 Kg of food intake. Pigs and poultry require something of the order of 2Kg of food for a 1Kg gain.
Western cattle appear to require less input because the nutritional content of their food is much higher than conventional pasture. Our cattle can be kept at much higher densities than free range, pasture-fed animals because food is bought in in the form of grains and concentrate. While it appears that our beef industry has a much smaller footprint than that in devloping countries, this is an illusion. Our beef depends on vast areas of grain and soya farming, much of it GM, to supply the artificial food chain that keeps it economic. Not to mention the other externalities such as energy costs, climate change, habitat/biodiversity destruction and slurry pollution.

At 10:26 am, Blogger Matt Burge said...

Yes I agree with Pete about the externalities of 'shed beef', which needs factoring into the 'western' beef energy ratio.

On a slightly different note (with your posting being concerned about land use for animal grazing and feed crops) there is the technology to grow crops in sand (ie. deserts), as they do in Israel very successfully. Not sure how environmentally sound this is or healthy it is for the customer though! But with dessertification on the increase this may be one answer, as long as deep bore water is available and is extracted sustainably.

At 2:25 pm, Blogger Pete Smith said...

Ah, water. Curving back to where we came in with the original post, the limiting factor on expansion of beef production may well not be land but water.
It takes 100,000 litres of water to produce 1 Kg of beef, compared to 3500 litres for chicken, 2000 for soya or 500 for potatoes.
'Water Resources: Agriculture, the Environment, and Society', Pimentel et al, BioScience, Vol 47 No.2, February 1997,
referenced at

At 5:38 pm, Blogger Matt Burge said...

100,000 litres!! Beef should be more expensive than gold.

At 5:42 pm, Blogger Stephan Smith said...

The figures came from a GMO industry report discussing marketing oppertunities in selling GMO based animal feed stuff to deveoping countries. I did check the figures before I posted and it does refer to protein conversion and not food intake. I wouldn't make such a fundimental mistake Pete...I was hoping the posting would stimulate thought on issues like equity, water, land rights etc... seems it did.

At 5:43 pm, Blogger Pete Smith said...

It does seem a lot doesn't it? Perhaps I misquoted, or correctly quoted a misprint. I shall check.

At 6:21 pm, Blogger Pete Smith said...

I've checked the original journal article, the figure of 100,000 litres for 1 Kg of beef is a correct reference. Apparently producing animal protein requires about 100 times more water than the same amount of vegetable protein.

At 6:26 pm, Blogger Pete Smith said...

Hi Stephan, sorry to ruffle your feathers by querying the figures. It would not be surprising for a GM industry report to use some creativity with the sums and the assumptions, resulting in a scenario that might justify GM.
I'm suspicious that they're not comparing like with like. Any chance of posting the reference?

At 7:59 pm, Blogger Stephan Smith said...

Hi Pete,

Have you seen the book - WHEN THE RIVERS RUN DRY by Fread Pearce?

It quotes 'Just to grow enough beef to make a quater-pound hamburger takes 11,000 litres[of water]'

The reference for the figures is:

Burke, J.F. and Thomas, S.M. (1977) Nature Biotechnology, Vol. 15 No. 8 August pp.695-696.

At 12:45 am, Blogger Pete Smith said...

Ho hum, I can't get online access to the Nature Biotechnology article. However, both authors appear to have been deeply involved with GM for a long time so I wouldn't expect to read anything that didn't prove the case for GM. It doesn't matter, the bottom line is the same whichever way you look at it:
more meat = more land / water / energy / cow crap.

At 1:01 am, Blogger Pete Smith said...

Oh, and by the way, the UN FAO says that we already use 29% of the world's land surface for livestock production, either by permanent pasture for grazing or croplands for animal fodder and feed.

At 11:14 am, Blogger Stephan Smith said...

Love your work!

Here's another take on the issue from The Oxford Uni Student Union:

"If everyone in the world were to eat the same amount of meat as we Britons habitually consume, over 5 billion hectares of farmland would be needed to feed us all. The Earth's land area is only 14.7 billion hectares. The vast swathes of rain forest already cleared for farmland are nothing compared with the land which would have to be committed if we all viewed a meat based diet as our right. Add to this the growing global population and the other demands we place on land, and the whole picture of the future dissolves into impossibility."

About what you'd expect from a bunch of hairy students wouldn't you say.

Chickens of the world be afraid...be very afraid!

At 4:08 pm, Blogger Keith Scott said...

So is this an overwhelming case for becoming vegetarian? I did see some articles recently about experiments on growing meat in tanks of proteins. Would this cut down the conversion ratio? Presumably it would.


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