Grain By-Products in Horse Feeds

To many people, by-products have a negative connotation. Most think of by-products as “left overs”, “junk” or “fillers”.  This is simply not true. Some of the most nutrient rich ingredients we have for horse feeds are made of the product that remains after a grain has been processed for another specific purpose. These ingredients can include things like brewer’s grain, corn gluten feed, oat groats, etc. Some of the most common members of this category that we see used in our horse feeds or even fed as a sole ingredient today are:

Wheat Midds are obtained from the milling of wheat, wheat bran, wheat shorts, wheat germ, wheat flour, etc.  Midds are a good source of energy, protein and fiber for horses. Additionally, wheat midds help create a nice pellet that holds together well; midds can enhance the pellet quality and make a clean pellet with minimal dust and fines.  

Rice bran is a by-product of the rice milling process. Rice bran is found between the outer hull and inner grain of rice and is used as a plant-based fat source (typical rice bran products contain 20% fat or more). Rice bran can be fed in a powder form, extruded into a nugget, or added to commercial rations and pelleted to increase overall fat content of the feed. Rice bran works well as an ingredient but must be balanced to make up for a high phosphorous and low calcium content. It also must be stabilized or it will turn rancid very quickly due to the high oil content.

Wheat Bran is a by-product of the flour industry. It is rich in dietary fiber and essential fatty acids; bran mash has been historically fed to horses both as a treat and for a laxative effect that was thought to prevent colic.  We now know that too much wheat bran can cause problems such as enteroliths, and that laxative effect is actually a result of too much wheat bran irritating the gut lining of the horse. Similar to rice bran, wheat bran intakes must be managed to account for a very high phosphorous content.

These are just a few examples of some common grain by-products that are used in horse feed and can help create a healthy and nutritious diet. While not a “grain” by-product, even the ever-popular beet pulp is a by-product – it’s what’s left after sugar beets are processed! Before you dismiss a feed because it lists by-product as an ingredient, remember that these items, when balanced properly as a part of the overall formulation of the diet, can be an excellent source of many different nutrients.

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!

Managing The Horse With Cushing’s

The vet has diagnosed it and the reality begins to sink in – your horse has Cushing’s disease. Now what?  Cushing’s is an endocrine disease caused by a tumor on the pituitary gland that is most often seen in older horses and ponies. This tumor results in high cortisol and is most often exhibited by  hyperglycemia (high glucose), excessive thirst, excessive eating, excess urination and a shaggy haircoat.  At this time there is no cure for Cushing’s but by keeping a close eye on nutrition and management, we can improve the quality and possibly lengthen the life span of a Cushing’s horse.

Routine is important to the Cushing’s horse because changes in diet, medication, etc. can have negative effects on health.  Cushing’s horses have a compromised immune system and for that reason, seemingly small or mundane parts of their care become very important.  There are a few management practices that are particularly important: 

  • Deworming – Cushing’s horses can be more susceptible to parasites because of their weakened immune system.  Work closely with your vet to develop a deworming schedule and program that is catered to your horse. Your vet should also be seen regularly for dental care and wellness exams.
  • Farrier Care– Regular farrier visits are important because certain types of leg and foot conditions are more likely with a Cushing’s horse, such as abcesses of the hoof and laminitis. Signs of laminitis can be a tender footed stance and the horse acting like he is “walking on egg shells”. 
  • Grooming – Hair coat and temperature regulation are problems in Cushing’s horses so you will want to help your horse as much as you can by preventative grooming practices. Consider body clipping in hot/humid weather and be mindful of temperature and weather changes. When blanketing, make sure the hair coat is dry and clean to help reduce the incidence of skin issues. Prompt treatment of any wounds or infections is essential.
  • Feeding– One of the main goals in feeding the Cushing’s horse is to control the starch + sugar (NSC) content per meal. This helps to regulate the blood glucose and insulin levels.  The NSC content of the concentrates fed to the horse is important, but even more so is the content of the hay /forage and the combination of the two together. Some guidelines have suggested an NSC maximum value of 10-13% based on the total diet (forage + concentrate). Testing your hay will give you a good idea of the NSC values.
  • Consider a feed that is fortified with lysine, methionine, biotin, vitamin E and complexed trace minerals (copper, zinc, manganese and selenium) to help maintain muscle mass, support hoof growth and support the immune system.

Following these tips will help improve the quality and possibly length of life for the horse diagnosed with Cushing’s.  If you have specific questions regarding your horse, please work with a qualified nutrition consultant or your veterinarian.

B-Vitamins in Horse Diets

Water soluble vitamins, which are the b-vitamins such a niacin, thiamine, folic acid, and many others, are excreted from the body on a daily basis in the urine.  B-complex vitamins play an important part in allowing horses to metabolize the nutrients contained in feedstuffs, by facilitating carbohydrate, fat and protein utilization within body cells, providing the energy needed for growth, performance and reproduction. All of the B-complex vitamins are essential to horses, but they are synthesized by bacteria in the cecum and colon. After microbes form the vitamins, they are absorbed through the intestinal wall and are available for use by the horse’s body cells. Bacteria in healthy adult horses generally produce adequate levels of the B-complex vitamins.

Since bacteria in the horse’s digestive tract produce B vitamins, several factors influence the B vitamin status of horses. Changes that affect the bacterial population may change the synthesis and availability of B vitamins, and they include, but are not limited to:

• Drugs, which selectively kill certain species

• Horses going “off feed” thus reducing the availability of food for the bacteria

• Dietary changes which change the levels of fiber, carbohydrate and protein passing to the bacteria in the hindgut

In addition, situations that decrease the horse’s ability to absorb B vitamins have an effect on overall vitamin status include:

• Chronic or clinical diseases that interfere with efficient metabolism by the horse

• Parasitism, through ulceration of the mucosa and direct competition for vitamins in the feed, causes reduce availability

• Diarrhea bouts reduce B vitamins for the horse

• Moldy feed, especially hay contaminated by Streptomyces, makes biotin unavailable for horses

• Stress tends to decrease the horse’s ability to absorb B vitamins

• Anti-metabolites present in plants such as bracken fern, yellow star thistle or horsetail, interfere with thiamin utilization and transport

Finally, information on the B vitamin requirements and synthesis in young, growing horses and performance horses is limited. While there is much anecdotal evidence available about the effects of supplementing b-vitamins to horses, few actual research studies have been completed to determine the actual results of such supplementation, positive or negative.

Feeding Tips for Stall Rest

Regardless of the diagnosis, when stall rest is on the treatment list, adjusting your feeding program to match your horse’s lack of activity can improve the experience for both you and your horse.

Horse on stall rest
As a curious 2 year old, Toby injured himself and landed in stall rest-land.

Whether recovering from an injury, surgery, or other, stall rest is generally prescribed to limit the movement of your horse to aid in the body’s natural healing process.  Often times, when a horse’s activity level moves from work or competition to that of quiet stall rest, it takes a period of adjustment for him to settle into the new routine.

Altering his feeding program to match this now sedentary lifestyle will help him make the transition.  Please note: all feed and forage changes should be made gradually through a period of 5-7 days so as not to disrupt the digestive system.

For the horse sentenced to a period of stall rest, the name of the game is energy management.  If he is an athlete who is used to getting high calorie feed and plenty of exercise, transition him to a lower calorie feed or ration balancer, with a high quality grass forage.  Reducing the energy he receives from his feed will help manage his weight and behavior.

Selecting a feed that is balanced for amino acids will offer the body aid in the development and repair of tissues, especially muscle and connective tissue. Fortified, balanced levels of vitamins and minerals will aid in immune response as well as minimize bone density loss.  Feed that is fortified with prebiotics, such as yeast culture, and probiotics can aid in the balance of the gut bacteria, overall absorbtion of nutrients and supports the immune system. Omega 3 fatty acids in the feed can also provide support for the immune system as well as help manage inflammitory response in tissue.

Monitor his body condition score and weight throughout stall rest and make feed amount adjustments as needed.  If he begins to gain weight, reduce his feed amount to the lowest advised amount from the feed manufacturer.

If he drops too much weight, slowly increase the feed amount, making sure to stay within the feeding directions.  Increasing the amount of hay can also provide benefits, though keep watch that he doesn’t start wasting.  Health complications or hay quality concerns aside, uneaten hay is an indication that he is being fed too much per meal.

In addition to providing much needed fiber and calories, hay in the stall can also provide a distraction,  curbing destructive behavior such a cribbing, weaving and pawing.  Consider providing stall toys, such as a ball or treat roller to keep his mind occupied and prevent bad stall habits from forming.

Pending the doctor’s orders, hand walking is a common method of providing limited exercise while reducing the chances of further damaging the injury or wound.  Hand walking is also a great way to spend time with your horse, especially if stall rest has taken him away from his normal job.

Once the period of stall rest is completed and he goes back to ‘work’,  transitioning his feed back to the ‘normal’ energy levels should be done with even more caution than transitioning the energy down.  For advise on your specific situation, please discuss with a qualified feed consultant or your veterinarian.

Vitamin K in Horse Diets

Vitamin K is one of the fat-soluble vitamins, meaning it can be stored up in the body.

The main function of this vitamin is for blood clotting to occur, which we all know is critical to our accident-prone horses!

The one use that most people will ever personally see Vitamin K administered for, is if the family dog happens to ingest rat poison, at which point the dog will receive an injection of Vitamin K from the vet. Rat poison functions by limiting the clotting ability of the blood, thus basically causing internal bleeding and eventual death of the animal. Vitamin K injections help restore the clotting ability, hopefully in time to reverse any damage.

In horses, forage sources and the bacterial activity in the gut upon ingestion of adequate forage produces enough Vitamin K, and thus it is not generally supplemented in the diet. Toxicities and deficiencies can occur, but are very rare.

How to Transition a Horse’s Feed

You may be thinking your horse might be in need of a senior diet, or perhaps there is a new feed available that you believe is even better for your horse.  Maybe you are no longer happy with your current feed.  Or, your dealer no longer carries the product you were using.  Whatever the reason, switching your horse to a new feed is a change that requires care and know-how. 

Changes to feed, pasture or hay in general should be made over a 7 day period, gradually increasing the new and decreasing the old.  For example:

Day 1: 80% of old feed / 20% of new feed

Day 2: 70% of old feed / 30% of new feed

Day 3: 60% of old feed / 40% of new feed

Day 4: 50% of each

Day 5: 40% of old feed / 60% of new feed

Day 6: 30% of old feed / 70% of new feed

Day 7: 20% of old feed / 80% of new feed

Moving from a feed higher in Non-Structural Carbohydrates (NSC) to one that is lower can be done relatively easily by following the instructions above.  If you are moving your horse from a ‘low’ NSC feed to one that is higher in NSC, feed changes should happen over at least the 7 days recommended above, if not longer. 

Research has indicated that horses fed pre and probiotics are better able to handle changes in diet than horses that are not. 

Changes in hay, though generally not given much consideration, can have as much of an impact if not more than changes in feed. If possible, try to follow the same steps as above when transitioning your hay.  Hay that is harvested from the same field, but in different cuttings will likely vary in nutritional content. Hay testing is available from many University Extension offices.  Check with your area extension office for more information.

Balanced Mineral Supplements for Horses

I had stopped at one of my large training barns to check on their horses diets, as they had just returned from a recent show circuit. The owner said the horses were doing well, but he was going to tweak their diets just a little. He had purchased a bag of selenium from a local milling company and just wanted to top dress a little extra.

Mineral Interactions in Horses

Unfortunately for him, the truth is that more is not always better. I explained how vitamins and minerals need to be kept in certain ratios and levels in order to keep horses healthy, and random adding of supplements can endanger their health.  For example, copper and zinc must be kept in a 3:1 t 4:1 ratio for proper bone growth, development and maintenance. In young growing horses, having this ratio out of balance could lead to Developmental Orthopedic Diseases. I also noted that not all are horse feed supplements are created equal.  In the case of minerals, organic complexed trace minerals (minerals that are tied to an amino acid) have increased bioavailability over the oxide or sulfate forms.  

Horses have mineral requirements which are broken down into Micro and Macro. Macro minerals include calcium, phosphorus, sodium, chloride, potassium, magnesium and sulfur. These are required in gram amounts in the diet. Micro, or trace, minerals include copper, cobalt, manganese, zinc, iron and selenium. These are required in much smaller quantities in the diet, and are measured in “parts per million”, or ppm. A part per million is equivalent to one drop of water diluted into 50 liters (roughly the fuel tank capacity of a compact car). Micro and macro minerals play an important role in bone development, muscle, hair coat , appetite, as well as skin and hoof integrity. The key is that they must be balanced in the horses diet.

Vitamin E in Horse Diets

Vitamin E is one of the fat-soluble vitamins, meaning it can be stored up in the body, and is of significant interest in horse nutrition. It is thought to be involved in muscular efficiency and may play a role as an antioxidant.  In growing horses vitamin E plays a key role in nerve and muscle development and function. Foals less than six months of age generally show gait in-coordination, with hind limbs more severely affected than fore limbs. Older foals and yearlings may show decreased muscular reflexes in the neck and trunk area along with muscle in-coordination (equine degenerative myeloencephalopathy).

Mares have an increased requirement for vitamin E due to rapid tissue synthesis by the foal in the last 2-3 months of gestation. About 60% of the foal’s body weight is deposited from months 9 through 11. Vitamin E is involved in muscle fiber formation in skeletal and cardiac muscle. Foals born to vitamin E-deficient mares tend to be stiff and weak and may be unable to rise. Often the tongue muscle is affected, leading to poor nursing ability.

Foal RestingVitamin E, together with selenium, functions within the immune system of the horse to protect cell membranes and enzymes from oxidation. One result of this function may be increased resistance to disease or stress. Because vitamin E levels are highest in fresh forages, horses show seasonal trends in serum vitamin E levels. Once horses are confined and have limited access to green pastures, vitamin E stored in adipose tissues, liver and skeletal muscles begins to be depleted. Daily supplementation of vitamin E through the feed helps maintain a constant vitamin E level in serum of horses.