The soy is processed, either mechanically or chemically. This separates it into soy oil, and meal which is the dry matter along with a small residual amount of oil. It’s this soy meal that is put into animal feeds. Soy is a preferred feed source because of its high crude protein content of 40-50% (depending on the exact processing method), balanced amino acid composition, and relatively high level of metabolisable energy.
It is notable that this soy is not necessarily grown where the animals are though. Although that may be the situation in some instances, for the majority of cases soy is a globally traded commodity. That means, just like fresh food for humans, soy as animal feed may have very significant ‘food miles’ attached to it - particularly for animals in those countries that do not grow food.
Soy and animal feed
When you think of soy, what springs to mind? Is it edamame beans? Perhaps it’s tofu, or some other meat substitute? Might it even be good old Soy Sauce? Whatever you think of first, it probably isn’t cows. The thing is though, it should be.
You might choose to eat tofu instead of beef, but the fact remains that the large majority of all the soy grown in the world goes to animal feed. It’s not just cows either. Most farmed animals get fed soy as a protein source in their diet; poultry, pigs, lambs and even farmed fish in aquaculture systems, all have soy as part of their diet.
The popularity of soy as an animal feed has grown a great deal in recent years. This is partly due to growth of the market for meat, particularly in the developing world. But it is also partly due to bans on the feeding of meat and bone meal (MBM) products to other animals, for example in UK where such feeds led to the outbreak of BSE which crippled the industry for a number of years. Finally, soy is relatively cheap, which only increases its popularity further.