Tue, Nov-03-09, 11:54
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Plan: LC Maintenance
Stats: 215/147/150
BF:
Progress: 105%
Location: UK
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Science has provided the key to unlocking the potential of food
I can't make up my mind whether to laugh or cry at this article:
Quote:
2 November, 2009
Science has provided the key to unlocking the potential of food
Sugar keeps sheep happy, and has revolutionised food production, says Steve Jones.
We live in extraordinary times, for food has, in effect, become free. At the end of the Second World War, it took the British working man about six hours of labour a day to feed a family of four; a figure which has now dropped by two thirds. Certainly, some items (particularly high quality stuff such as fresh fruit or fish) have become relatively more expensive, but many others, such as soft drinks or white bread, are much cheaper. All this is evidence of a revolution in farming. It began in the States during the Thirties, when breeders found that to inter-cross different strains of maize vastly improved output, and has continued unabated ever since. Plant science, the forgotten hero of biology, has transformed economic – and physical – landscapes across the world.
That is as true of my own native land, west Wales, as anywhere else. Fifty years ago many hill farmers’ fields were sparse, their thin grass a fodder for sheep and cattle. The animals are still there, but for them – as for us, and for the same reason – eating has got easier. Today’s fields are greener and the lambs fatter than in my youth and that has a lot to do with science.
The sheep’s new life – like ours – comes from sugar. Easily digested and irresistible to beasts and men, sugar is the drug of the 21st century. Glucose syrup from maize is the raw material that makes junk food, from fizzy drinks to chicken thighs. In the States, the trash-food capital of the world, most cattle never see grass but are fed on maize or on sugar-supplemented pellets in giant feed lots, which makes economic if not aesthetic sense.
In 1953 a grand estate called Gogerddan, close to my family home in Ceredigion, became the home of the Welsh Plant Breeding Station. Its much-enlarged descendant has just fused with Aberystwyth University to become the Institute for Biological, Environmental and Rural Science, a flagship of Aber’s intent to become Britain’s leading eco-university. I was there last week, on a panel discussing how to maximise the output of the new and vigorous hybrid. It was a fascinating trip.
Its plant-breeders have developed new grasses that contain much more sugar than before. Sheep are surprisingly bad at turning grass into meat or wool, for they use only around a fifth of the protein potentially available, returning the rest to nature via their rear ends (they also burp a lot).
The fault lies with their fellow-travellers, the billions of single-celled creatures in their guts that do much of the work of digestion. Starved of sweet fuel, the bugs cannot work hard enough to break up great wads of vegetation as they progress through the animal. Much of the energy in ordinary grass is locked away as cellulose, but the new strains make more sugar within the cells. The bugs can then soak it up, use it to power their own digestive factories, and break up more grass protein to feed their hosts. Lambs grow a fifth faster (and cows make more milk) on the new crop. That is good news for farmers and even better for farms because less nitrogen-rich manure pours out to poison fields and pollute rivers.
Sheep and cattle are ruminants: they have a sort of pre-stomach in which helpers partially digest the meal before it is returned to the mouth for a second round of chewing, followed by dispatch to the stomach proper.
We do just the same, except that we use saucepans. Cooking softens food, and releases sugars and other products ready for absorption. As a result we have to spend much less time chewing than do our relatives (an hour or so a day, compared with six times that for chimpanzees) and have far smaller teeth, tongues and intestines than they do. The spare energy released by the first cooks, long ago, went straight to our heads. The evolutionary way to man’s brain was, as a result, through his stomach. Brains burn lots of fuel. Chimps have no hope of getting as smart as us, for their diet and simple guts could never provide enough energy to sustain such an expensive organ. We are as dependent on our frying pans as sheep are on their internal fellow travellers, for if you eat nothing but raw food you will starve to death.
Will those sugar-supplemented Welsh fields in time enable farm animals to evolve bigger brains to match their richer diet? In these straitened times, might boiled grass become a cheap and tasty item for Aberystwyth students? It’s worth ruminating about, at least.
Steve Jones is professor of genetics at University College London
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http://www.telegraph.co.uk/science/...al-of-food.html |
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