Every day it seems there is a new dieting fad in humans — low carb, paleo, vegan, the list goes on. No matter the diet, all biological living things need certain nutrients to function. Your horse needs these nutrients, called macromolecules, just like humans do.
What are macromolecules and why are they important?
Macromolecules are the building blocks of living organisms. They provide the body with the energy and nutrients needed to power day to day activities. There are four macromolecules necessary in the diet.
- Carbohydrates are made up of glucose (a simple sugar) and provide a quick source of energy.
- Fats, also known as lipids, are stored as a longer-lasting source of energy than carbohydrates. They also can help insulate the body from the environment.
- Proteins are made up of smaller molecules called amino acids. While they are not a great source of energy, they have the largest variety of functions. This includes powering and building muscle, sending important body signals, and transporting smaller molecules within the body.
- Nucleic acids provide the materials needed for the genetic makeup of the individual, carrying the instructions needed to make your horse unique.
How much of each macromolecule does my horse need?
A variety of factors can influence the exact ratio of nutrients each horse requires. Age, breed, and performance level are some examples — a 20-year-old retired thoroughbred will have different dietary requirements than a 7-year-old quarter horse being worked six days per week.
According to the Professor of Equine Nutrition at North Carolina State University, Dr. Shannon Phillips, a standard 1100 lbs horse being regularly exercised needs:
- About 630 grams of protein. This number increases or decreases with a higher or lesser workload.
- 16.67 megacalories per day. Megacalories are 1000 times the typical human calories we think of. Humans need about 2 megacalories per day. Calories are a form of energy and are obtained from a combination of fats, carbohydrates, and proteins.
There is no exact number of carbohydrates, fats, and nucleic acids required in a horse’s diet. Nucleic acids are obtained from most food sources and do not need to be considered to the level that the other three macromolecules are.
Carbohydrates and fats, as excellent sources of energy, can be added or removed based on the horse’s caloric (energy) output. The workload of a horse is characterized as idle (pasture only), light, moderate, heavy, or intense (competing racehorse). For horses with a larger workload, carbohydrate and fat requirements increase significantly. Since protein is a mediocre energy source, it’s requirements increase at a slower rate.
Where can my horse obtain macromolecules?
All four macromolecules can be obtained from hay and grasses. However, a hay only diet might not be able to provide enough of each for the level of work required of horses today, especially those in competition. Supplementing grain concentrates can be useful for horses who have high-calorie requirements, increasing the protein, fats, and carbohydrates.
Am I feeding the correct grain concentrate for my horse?
In reading a guaranteed analysis feed label, you will see a list of nutrients with a percentage next to them. Oftentimes, horse owners focus on these percentages, looking for the highest protein or the lowest carbohydrate percentage. Or they may not understand and simply feed a scoop of whatever brand was recommended to them — if this is you, don’t feel bad. We’ve all been there.
Horse owners should consider the weight of the feed using grams rather than the percentage listed on the package. This is because the percentage is based on feeding a certain amount of grain. If more or less of this amount is fed, the horse may be receiving too little or too much of the nutrients. An example of how to calculate the weight is given below.
A certain grain with 12.00% crude protein recommends feeding a moderate activity level horse 0.5 lbs of feed per 100 lbs body weight. It is being fed to an 1100 barrel horse in training a few days per week. 1 lb is equal to about 454 grams.
- Calculate the weight of what is being fed in grams
- Calculate the amount of protein using the percentage
2,497 grams x 0.12 = 300 grams of protein
Compare this value with the protein levels in the horse’s forage diet to determine how much total protein the horse is eating per day.
What happens if I overfeed these nutrients?
Overfeeding protein is a common occurrence with many horse owners due to the high levels within grain concentrates. Excess protein in the horse’s body is released through urine output. It does not hurt the horse but can hurt your wallet if you are paying for supplements that are not being utilized by the horse.
Overfeeding fats and carbohydrates can have a negative impact on your horse’s health — starch-based carbohydrates especially.
Horses digest their food in their hindgut, using bacteria and protozoa to aid in fermentation. This causes them to have a limit to the amount of starch their body can digest. Excess starch sits in the hindgut, leading to dangerous problems including:
- Colic — abdominal pain in horses which can range from mild to deadly depending on the severity.
- Laminitis or founder — the irreversible downward rotation of the coffin bone in the foot of the horse, causing immediate and severe pain. Most common in the front feet, too much rotation results in a poor prognosis for the horse.
- Equine Metabolic Syndrome (EMS) — recognized by unusual fatty deposits on the horse and insulin resistance, it is a form of pre-diabetes for horses. Laminitis is also sometimes seen in conjunction with EMS.
Oats, corn, and barley are all sources of starch and, if fed, should be done in moderation. If you are worried that you may be overfeeding your horse, you can contact your trusted vet or an equine nutritionist (or both!) to help you create a plan best for your horse.
I feed free-choice hay, should I be concerned about overfeeding?
The digestive systems of horses are designed for grazing all day. Their stomachs constantly secrete acid to break down food, even when empty. If the stomach is left without food for long periods of time, this acid can damage the lining of the stomach, causing ulcers.
Access to a constant food supply can be beneficial in preventing ulcers in horses. However, some horses, especially ponies, can overeat and gain weight easily. You may find that feeding in intervals works best for them. Thus, finding a balance between feeding too much and too little forage is a tricky balance. A few considerations can help you develop the best forage feeding program for your horse.
- Fiber is a type of carbohydrate that has been shown to be beneficial to maintaining a healthy digestive system in horses. Roughage sources, including beet pulp, are good sources of fiber and can replace high-starch sources.
- Alfalfa hay has been shown through research to be the most effective forage at preventing and reducing ulcers. It works by buffering the horse’s stomach from the acid production more effectively than other types of hay.
- Equine Nutritionists can help you to best decide what kind of feeding program would best fit your lifestyle and horse. If you are concerned about ulcers, your trusted veterinarian can diagnose and develop a treatment plan.
How can I tell if they are getting the right amount of nutrients?
- Complete a hay analysis. These are relatively inexpensive (usually about $20) and can determine which nutrients are lacking in your horse’s forage diet. You can then consider switching hay types or supplementing as needed.
- Calculate grain nutrients. If you are feeding grain or supplements, use the weight of the serving and the percentage on the label to determine how many grams of each nutrient your horse is receiving. Do they need more or less of something?
- Evaluate your horse’s body condition. Is your horse underweight or overweight? Is their coat glossy or dull? Your trusted veterinarian can help you in this assessment.
- Complete blood work on your horse. Have your vet take a blood work sample to determine protein, sugar, and electrolyte levels (those are important too!). Your vet can recommend diet changes if anything is out of balance.
Whether your horse is a competitive athlete or a fun adventure buddy, they need the right balance of macromolecules to look and feel their best. Feeding them correctly will help them perform at the top of their ability and live a long and happy life as your best friend.
Originally written by: Madison Gray
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