Protein makes up approximately 15% of total body mass. Proteins are required for many functions in the body, such as providing structure (i.e., contractile proteins actin and myosin in the muscle, collagen, keratin), nutrient transport in the blood stream, nutrient transport across cell membranes, regulation of metabolic function and immune function.
Before we go too far, please know that good quality protein will NOT make your horse hot, and is actually not an efficient energy source. Carbohydrates and fat are much better fuel sources.
Protein is made up of amino acids. There are essential amino acids and non-essential amino acids. Essential aa’s must be provided by a dietary source, while non-essential aa’s can be made by the animal’s own metabolic processes to meet requirements.
When it comes to the amino acids that actually make up protein, lysine is the #1 limiting amino acid, with threonine and methionine being close behind. This means that protein synthesis is limited to the level of lysine in the diet. So, if there isn’t enough of the essential amino acid lysine in your horse’s diet, all other essential amino acids will be limited. Thus, it’s vital that your horse has enough lysine in their diet.
Protein can come from forages, feeds and protein supplements, and not all protein is created equal. When it comes to forages, legumes (alfalfa, clover) are typically higher in protein than grass hays. Protein content and quality in commercial feeds is dependent on the individual product. Soybean meal and alfalfa meal are great protein sources with a strong amino acid profile-look for these sources when buying your feed. Cereal grains such as wheat, corn, millet, rice and rye do not contain high quality protein. Targeted protein supplements are also a great way to add protein to your horse’s diet and are often comprised of whey protein, alfalfa meal and/or soybean meal.
So, how do we actually determine how much protein is in our horse’s diet?
Here’s the simple math!
There are approximately 454 grams in 1 lb. To figure out grams of protein per pound, take the % and convert it to a decimal, then multiply by 454.
If a feed says it contains 20% protein, the equation would look like this:
.20 X 454 = 90.8 grams
If you are feeding 4 lbs of that feed per day, just multiply your answer times 4.
90.8 grams X 4 = 363.2 grams
363.2 grams is how many grams per day your horse is getting in protein from that feed.
NOW, if you are feeding 2 lbs of a balancer that has 30% protein, the equation would look like this:
.30 X 454 = 136.2 grams
Multiply that answer by 2 lbs
136.2 grams X 2 = 272.4 grams
What did we learn? The 30% balancer fed at the recommended 2 lbs actually contains less protein than the 20% feed fed at the recommended 4 lbs.
The take away is don’t be fooled by the percentage advertised! The amount of protein your horse is receiving from their feed is entirely dependent on the amount being fed, NOT the advertised percentage.
Don’t forget that forages also supply protein. If you know the percent of protein in your grass and/or legume hay, and you know how much you are feeding in weight, you can follow the same calculations as above. If you don’t have a hay analysis to tell you the exact percentage of protein, it’s helpful to know that most grass hays range in protein from 8-14%, while legumes range from 14-22%.
Protein requirements vary based on your horse’s unique needs-their weight and their workload. If you need help determining how much protein should be in your horse’s specific diet, schedule a discover call with me and we can dig deeper into your horse’s nutritional needs.