Protein Ingredients in Horse Feed

Protein (and more specifically the amino acids that make up protein) is essential to a balanced diet. It is probably one of the most referenced nutrients in horse feed, and most horse owners will know the protein content of their feed. But how do we get the protein into the feed? Sources of protein for humans may come from a juicy steak, a nice salmon filet, or a tender pork chop. We derive most of our protein from meat sources which makes sense for us since we are carnivores. The horse, on the other hand, is an herbivore; many of the types of protein that we consume as humans do not come into play in our horse’s diet. However, we do know that the horse has a nutritional requirement for protein and so when we formulate feeds we can use certain plants that are high in this particular nutrient. Some of the most popular ingredients used to add protein to horse feed are:

Soybean Meal – This is the most common form of plant protein. Soybeans are readily available throughout the country and have the highest concentration of protein of any of our plant sources, with a typical level of 44-48%. Additionally, soybean meal contains a close match nutritionally to what horses require for amino acids. Especially important in this profile is the amino acid lysine, which is essential in young growing horses.

Canola Meal – Canola meal is the closest to meeting the nutritional profile of soybean meal and has a protein content of 35-44%. Canola meal is a by-product of oil removal from

canola and has slightly less lysine content than soybean meal, but still enough to meet the requirements of horses.

Linseed Meal – this is also a by-product and is derived from the processing of flaxseed. Linseed used to be commonly fed to show horses to add shine and bloom but its popularity has waned as ingredients like rice bran and vegetable oil have taken its place. Linseed meal has a typical protein level of 33 – 35% but it has significantly less lysine than either soybean or canola meal.

As you can see, we have several options to help us meet the requirements that our horses have for protein. By adding one or more of those options to our formulas we are able to provide a diet that is balanced, healthy, and nutritious!

Unbalancing a Balanced Horse Feed Diet

I was helping a colleague do a horse nutrition training seminar the other day and the question came up “Is it okay to supplement a commercial feed?” Specifically, this person was feeding half oats and half SafeChoice to her horse. My colleague had a great answer for this. He picked up a half full glass of Coke – “Pretend this is SafeChoice. Balanced perfectly to provide just the right things in the right amounts.” Then he picked up a pitcher of water – “Now pretend this is the oats. Not nutritionally balanced, low in protein and high in starch.” He started pouring the water into the glass until the mixture reached the top. The result was a watered down, light brown mess that looked unappealing and I am sure tasted the same way. The message here is simple – commercial feeds are formulated to be complete in their vitamin/mineral content, protein level, energy and fat levels. When fed at the recommended amounts per day based on work level you are meeting your horses’ nutritional requirements and delivering a specific and targeted amount of nutrients. There is no need to add/substitute/mix anything else. If you take that same feed and mix it (with things like straight grains, sweet cob, etc) – the result is an unbalanced feed that does not meet the needs of the horse. The protein gets lowered, the vitamin and mineral contents become diluted and things like calcium and phosphorous and copper and zinc can get out of balance. What you get is a diluted mess that is only doing half the job. To get the full benefit of a commercial balanced feed, use it according to tag directions and resist the urge to dilute it with anything else!

When Should I Feed a Complete Horse Feed?

A complete feed is a fortified grain/forage mix that is formulated with high quality fiber sources to raise the total percent fiber in the feed, so that reduced hay feeding can be done safely. Some fiber sources in complete feeds include alfalfa, beet pulp, and soy hulls. These are all good digestible fiber ingredients for horses.

Here are some of the many reasons why you might decide to feed a complete feed.  

  • You have a horse with poor teeth or no teeth that can no longer chew and swallow hay. This can be a young or old horse.
  • Good quality hay is hard to find, obtain, or pay for. This situation will most likely occur in:
    • Drought situations when plants aren’t growing or they are very mature when they get tall enough to cut. When a plant gets too mature it has high levels of lignin that can’t be digested by the horse leading to digestive upsets or increased risk of colic. Plants also lose nutrient content the more mature they get.
    • Extremely wet conditions because it may be more mature by the time a farmer gets good weather to cut it and flooding can also bring debris onto fields that can be harmful to your horse.
    • Situatinos where hay gets more expensive as fertilizer and fuel costs rise.
  • There is a lot of hay wasted from handling, transporting, ect. More hay is wasted when horses are fed round bales. When hay is expensive and there is a lot of waste, complete feeds may be more cost effective.
  • Hay is hard to handle and round bales/large square bales require a tractor for handling and other equipment such as a flatbed trailer. Equipment requires fuel, tires, maintenance, ect. The cost of handling hay should be brought into consideration when cost is a major factor in feeding.

Long stem forage is an important part of the horses diet and a good source of forage should comprise of at least 50% of the horses daily intake when possible. However, when any of the above conditions exist it may be necessary to feed a complete feed only or reduce the amount of hay being fed. A horse that can no longer chew hay will need to get all of his daily requirements from a complete feed that is easy to eat such as a senior complete feed with softer pellets that can also be fed as a wet mash. If hay shortage, hay cost, or drought is the reason you feed a complete feed you may want to continue feeding some hay in the diet for long stem forage if possible.

It is important to read and follow the feeding recommendations when buying a complete feed, and they should list the recommended feeding amount both with and without hay on the tag. As you decrease the amount of hay, you will need to increase the amount of complete feed. Here are two examples of complete feeds and how much to feed a 1,000 lb maintenance type horse with no hay and with hay/pasture.

  • A senior horse feed – generally a highly digestible and highly palatable product that can be fed as a complete feed, and is designed for older horses. 
    • A 1,000 lb maintenance type horse would receive 12 – 14 lbs of a senior feed, if no additional hay is fed.
    • The same horse, if it was being fed hay, would receive 5 – 7.5 lbs of the senior feed.
  • A traditional complete horse feed – known as “hay replacers” or “hay stretchers” - are a complete feed that combines high quality roughage and grains in a pelleted form. It can be fed as a complete feed or with forage. 
    • If no hay is fed, a maintenance type horse would receive 1.5 lbs per 100 lb body weight. A 1,000 lb horse is recommended to get 1,000/100 = 10 x 1.5 lbs = 15 lbs of a complete feed.
      When feeding along with hay or pasture, a typical recommended amount to feed a maintenance type horse 0.5 lb per 100 lb body weight or 5 lbs.

Whether you chose to feed a complete feed with hay or without, it is important to feed the recommended amount and make adjustments as needed depending on if your horse is an easy or hard keeper. It is also important to provide free choice salt and clean, fresh water at all times. Complete feeds should be split into two or more feedings. Horses should be switched slowly from one feed to another and also when eliminating hay from the diet. When reducing the amount of hay fed, it is recommended to reduce hay over 1-2 weeks.