UK Guardian – a recent study calculates that cultured meat has 80-95% lower greenhouse gas emissions, 99% lower land use and 80-90% lower water use compared to conventionally produced meat in Europe. Every kilo of conventionally produced meat requires 4kg-10kg of feed, whereas cultured meat significantly increases efficiency by using only 2kg of feed. Based on our results, if cultured meat constituted half of all meat consumed we could halve the greenhouse emissions, and increase the forest cover by 50%, which is equivalent to four times of Brazil’s current forest area.
Cattle require 8-10 kilograms of feed per kilogram of live weight. Poultry require 3 kilograms of feed per kilogram of live weight. Fish, because they are poikilothermic (“cold-blooded”), only require 1.2 to 2 kilograms or less of feed per kilogram of live weight. No energy is required to maintain body temperature.
The first versions of genetically engineered fish are 10-30% more efficient at converting feed into body mass. Genetically engineered fish are more efficient than lab grown beef in converting feed into body mass.
Sheep and cattle FCR 8 kg of feed to put on 1 kg of live weight
Pork (pigs) FCR of 3.4-3.6
Farm raised Atlantic salmon FCR of about 1.2
Tilapia, typically, 1.6 to 1.8
Poultry (chicken) has a feed conversion ratio of 2 to 1
How do you free up huge amounts of farmland to grow more food for humans? Easy – switch to commercial algae farms. Algae are simple, single-cell organisms that can grow very rapidly at sea, in polluted water and in places that would normally kill food crops.
Scientists say that under optimum conditions, commercial algae farms can produce 5,000-10,000 gallons of oil per acre, compared to just 350 gallons of ethanol biofuel per acre grown with crops like maize. In addition, algae could feed millions of animals and act as a fertiliser. Replacing all US ethanol (biofuel) production with algae oil would need around 2m acres of desert, but, says Arizona State university professor Mark Edwards, it would potentially allow 40m acres of cropland to be planted with human food, and save billions of gallons of irrigation water a year.
Algae are at the bottom of the food chain but they are already eaten widely in Japan and China in the form of seaweeds, and are used as fertilizers, soil conditioners and animal feed.
China has new super rice that will increase yields by 15% over the 2004 version of rice. They are targeting another 15% gain in yields by 2020. This gain was achieved without genetic engineering. Genetic engineering may increase the speed of yield improvement.
FCEs are generally higher for insects than for vertebrates. One must be careful in making such comparisons, however. One problem is that insect values are reported on the basis of dry weights, whereas livestock values are reported as “gain” which typically includes 70% water. After adjusting for water weight, ballpark figures for efficiency of gain are seen below. Clearly, the insects are superior to mammals when fed the same food. FCEs of vertebrates can approach or even surpass those of insects when they are fed especially nutritious and digestible food such as grain.
Chicken (grain) 30%
Pigs (grain) 11 %
Beef (grain) 5%
Beef (grass) 3%
About rearing grasshoppers on forbs: I would expect higher ECIs than when reared on grass. Insects fed grass are in the 8-30% efficiency range. So the best insects are in the efficiency range of chicken.