N
noblemchikezie
Guest
The recent breakthrough in cereal production has not solved the needs of the world's expanding population for cheap sources of protein, so the problem is also being attacked on several other fronts. The British Petroleum Company has developed yeasts which produce protein from the waxy by-products of oil refining. A factory at Grangemouth, Scotland, is capable of producing 4,000 tons of protein a year, and plans are afoot to build a plant in Europe with four times this capacity. At present the major use of the yeast protein is in animal feed, but uses will doubtless expand.
Another British company, Courtaulds, is producing meat substitutes from soybeans. The protein is extracted and extruded from the soybean as fibers and then flavored; it can be stored dry and reconstituted as required, and it costs less than 10 cents a pound. But meat substitutes are rarely acceptable, so cheap forms of animal protein are desirable.
dwarf leghorns produce eggs more economically than regular hens: three dwarf fowls consume the same amount of feed (160 pounds) and can be kept in the same-sized cage as two regular hens, but the dwarfs produce about 200 eggs each a year, as opposed to 240 eggs each for the two hens of conventional breeds.
Fish can be raised at far lower cost than warm-blooded animals (birds and mammals), which are inefficient at converting food into protein. In their work on the nutrition of trout and salmon, David Locke and Stanley Linscott at the Maine Department of Inland Fisheries have produced feeds using defatted fish offal processed by Astra Pharmaceuticals. The dry weight of feed needed to raise 1 pound of fish is 1 to 1.6 pounds, and the cost is 25 to 38 cents a pound of fish.
Using silos instead of raceways, Keen Buss and his colleagues at the Benner Fish Research Station in Pennsylvania have raised trout at very high density; a silo holding 50,000 pounds of water yielded 6,000 pounds of trout in 22 weeks. The upper limit of density depends on water exchange, but experimentally the Benner researchers have successfully kept 7 pounds of fish in 7 pounds of water. Trout require animal protein, but channel catfish, which are not a luxury food, can be fed on mixtures based on soy flour. The cost of these feeds is only 8 cents per pound of fish, according to O. W. Tiemeyer of Kansas University, but the fish grow well only in semitropical conditions.
Another British company, Courtaulds, is producing meat substitutes from soybeans. The protein is extracted and extruded from the soybean as fibers and then flavored; it can be stored dry and reconstituted as required, and it costs less than 10 cents a pound. But meat substitutes are rarely acceptable, so cheap forms of animal protein are desirable.
dwarf leghorns produce eggs more economically than regular hens: three dwarf fowls consume the same amount of feed (160 pounds) and can be kept in the same-sized cage as two regular hens, but the dwarfs produce about 200 eggs each a year, as opposed to 240 eggs each for the two hens of conventional breeds.
Fish can be raised at far lower cost than warm-blooded animals (birds and mammals), which are inefficient at converting food into protein. In their work on the nutrition of trout and salmon, David Locke and Stanley Linscott at the Maine Department of Inland Fisheries have produced feeds using defatted fish offal processed by Astra Pharmaceuticals. The dry weight of feed needed to raise 1 pound of fish is 1 to 1.6 pounds, and the cost is 25 to 38 cents a pound of fish.
Using silos instead of raceways, Keen Buss and his colleagues at the Benner Fish Research Station in Pennsylvania have raised trout at very high density; a silo holding 50,000 pounds of water yielded 6,000 pounds of trout in 22 weeks. The upper limit of density depends on water exchange, but experimentally the Benner researchers have successfully kept 7 pounds of fish in 7 pounds of water. Trout require animal protein, but channel catfish, which are not a luxury food, can be fed on mixtures based on soy flour. The cost of these feeds is only 8 cents per pound of fish, according to O. W. Tiemeyer of Kansas University, but the fish grow well only in semitropical conditions.
