Soy is a food that horse would never eat naturally yet exist in nearly every horse feed that is made. How did that come to be?
Soy is one of the most highly genetically engineered crops in the US. The purpose of genetic engineering it is to create bigger yields and more resistance to pests as well as making the plant resistant to being sprayed with herbicides and insecticides. This way a farmer can spray his whole field with glycophosphate, for example, in order to kill any other plants that might be growing in the field other than the desired crop. This prevents the farmer from having to hand-pick or spray each invasive plant individually thus saving a lot of time and money. So that means that your food crop is left with the residue of the herbicide being sprayed. Glycophosphate is highly toxic and is a known carcinogen.
Soy is an important crop due to its ability to “fix nitrogen”. Plants that fix nitrogen make nitrogen available in the soil. This is an important job because nitrogen is abundant in the atmosphere but plants cannot absorb it from the air they must get it from the soil and nitrogen is one of the primary nutrients used by plants. Soy is used as a “rotation crop” because of this ability to add nitrogen back into the soil. This means that farmers can plant their field with soy after they have grown crops that leave the soil depleted of nutrients, such as corn or wheat, and soy will restore the field with this essential nutrient. The best part is you also get to sell the beans. Two for the price of one, field fertilization and a cash crop, this makes it a valuable crop to produce.
Soy is very high in protein and is a cheap and easy way to add a reliable protein source to a feed but it is not a good option as a feed for animals and this is why…
Soybean meal is what is typically used in feeds. This is a byproduct of the soy oil industry it is the flour left over after the oil has been extracted. In order to extract the oil from soybeans solvent have to be used which are usually highly toxic substances or the beans are heated and squeezed. Either way they are processed, the leftover product is much less potent in nutritional value. Another important thing to consider is that soybeans cannot be eaten raw because they contain enzyme inhibitors that disrupt protein digestion. They must be cooked because if not they are highly toxic to horses or any other species including humans
Below is a list of important reasons why soy can be harmful to eat:
- Soy contains enzyme inhibitors that disrupt protein digestion
- Soy contains haemagglutanin which promotes blood clotting
- Soy contains goitrigens that can contribute to the formation of goiters, which older horses are particularly susceptible to developing
- Soy is high in phytates, which bind certain minerals such as zinc and calcium, making them less absorbable
- Soy contains phytoestrogens which disrupts endocrine function
- Soy contains high levels of Aluminum and Manganese both of which can be toxic in high levels
- Soy contains free glutamic acid which acts as a neurotoxin
My advice is to stay away from soybeans as a feed for horses!