Producing soya beans is responsible for some significant amounts of deforestation in tropical areas and relying on soya introduces a demand for transportation in countries where soya is not grown.
I know that soya is used as a feed for livestock. I don't know the statistics for dairy livestock, but an advantage of cows is that they can produce food from local land which is only able to support grass but not crops, and they produce manure.
Question is how much soya, if any, is typically used in developed countries to produce a glass of ordinary full-fat/semi-skimmed milk? How do more developed compare with less?