Ethical, Legal, and Social Implications
Environmental Impact of Dairy Industry
ToDo: Copy the stuff from the BioCoder article here. Link UN report on impact of dairy industry.
Efficiency of biomass conversion
Note: These are all very rough first estimates. Don't rely on this. Needs more research.
"...biomass formation can be achieved by innumerous metabolic pathways (Frick and Whitmann, 2005) and biomass yield on substrate can reach values up to 50% in pure oxidative growth (Akinyemi, Betiku and Solomon, 2005)." source
If we can get 1% to 3% casein yield per biomass, then we could maybe get between 0.5 to 1.5% casein per substrate efficiency.
Some info on dairy cow efficiency
Normal milk is about 2.6% casein. If a normal cow produces 25 kg of milk and consumes 25 kg feed per day (which is approximately normal), then that is about 2.6% efficiency.
Anti-GMO Sentiments
Here's a good resource from the skeptiforum wiki
According to estimates, between 80 and 90 per cent of cheese in the USA and Great Britain is manufactured using chymosin produced using gene technology[1].Most of the rest is produced using rennet extracted from the stomachs of suckling calves[2]. "Take your pick: eat GMO cheese, or be a baby-killer?"
The "Yuck Factor": Eating Human Proteins
Even among people who are perfectly willing to contemplate genetically engineered cheese, there seems to be a distinct "yuck factor" regarding using the human genes, even though there could be significant health benefits to doing so.
As an additional mind-twister: if we use the human reference sequence, we would essentially be making cheese from Craig Venter's genes...