All markets differ from region to region. Soybean meal from Brazil, for example, has a higher protein content than does soybean meal from the United States, which makes it especially popular in China. But the two products resemble each other enough that a Chinese buyer will grudgingly accept the latter in lieu of the former – albeit at an agreed upon discount.
That's one of the things that makes soybean meal a commodity', and its status as a commodity is one of the things that makes it so easy to trade.
