feeding young and growing horses

Feeding young, growing horses properly is vital to ensuring they grow into useful and productive adults. Good-quality hay is the cornerstone of their diets, but selecting the right concentrate feed is also key to ensuring nutrient requirements are met.

So, what’s in your growing horse’s feed? Look to the tag—it can help you figure out if the bag’s contents are suited for your horse. The Association of American Feed Control Officials (AAFCO) requires companies to label their feeds with specific information that assures owners of nutritional quality. This tag, which is either printed directly on the bag or sewn into the bag’s closure, should include:  

Lot number

This should be on the tag or printed somewhere on the bag (probably the bag’s bottom or near the seam where you open it). Use this number to track the product if there is a recall.  

Product name and purpose statement

Sometimes these figures are combined, but the product name, along with a description of the type of horse (e.g., foal, broodmare, maintenance) the feed is intended for, should be at the top of the tag. The name might also have an indication of the feed’s nutrient content. For example, “Horse 10:8″ might indicate the feed has 10% protein and 8% fat and is formulated for adult horses. A young horse feed tag might specify that it is a “feed for young, growing horses” or “formulated for growing horses and broodmares.”  

Guaranteed analysis

Here the company indicates, as accurately as required, the feed’s nutritional content. Based on AAFCO guidelines, the tag must include:

  • Crude Protein (min): The minimum amount of protein that must be in the bag. The actual amount might be higher, but it can’t be lower or it would be in violation of what the company guarantees. Crude protein simply represents the amount of nitrogen (a component of protein) in the feed and not true protein. It also doesn’t give any indication of the protein’s quality with respect to amino acid content.  
  • Crude Fat (min): The minimum amount of fat in the feed.
  • Crude Fiber (max): The maximum amount of fiber in the feed, but the actual amount might be lower.  
  • Calcium (Ca) (min and max): A range for the calcium included.
  • Phosphorus (P) (min): The minimum amount of phosphorus.
  • Copper (Cu) (min): The minimum amount of copper.
  • Selenium (Se) (min): The minimum amount of selenium. Or you might see at the top of the feed bag, just under the product name/purpose statement, “This feed contains 0.3 mg/kg selenium.”
  • Zinc (Zn) (min): The minimum amount of zinc.
  • Vitamin A (min): The minimum amount of vitamin A (this is true vitamin A that is added, not beta-carotene, which is a provitamin of vitamin A, meaning it’s converted to such within the body).

Feed control officials are looking to add additional fiber fractions to AAFCO label requirements in the near future:  

  • Acid detergent fiber (ADF) (max): The fiber component that includes lignin and cellulose.  
  • Neutral detergent fiber (NDF) (max): The fiber component that includes lignin, cellulose, and hemicellulose.  

Also, if the feed manufacturer makes any claims, such as “added vitamin E,” it should list the amount.  


Each tag should include an ingredients list. The terms listed might be true individual ingredients or collective terms, such as “grain products.” This list gives no indication of the grade of ingredient, such as Grade A corn. Ingredients are listed from the highest amount to the lowest, with no indication of the actual inclusion amount. For example, a product label might list: Wheat middlings, oats, alfalfa meal … and have 80% wheat middlings and only 10% oats and 3% alfalfa meal. Vitamin ingredients are listed as “vitamin supplement,” and other non-nutritional ingredients (preservatives, etc.) might be itemized, as well.  

Directions for use

All commercial feed manufacturers should provide some directions with each product, whether written out or presented as a chart (see page 36 for an example). These typically list amounts of feed a horse at a given weight and level of growth, work, etc., requires.  

Manufacturer’s name, address, and net weight of the bag

This is required because local mills might mix a popular commercial brand’s formula for the manufacturer.  

Other information might include general horse health guidelines (e.g., always provide water).  

Note that feed manufacturers must follow specific AAFCO guidelines on labels provided with or attached to actual products. But they are free to include additional information on their company and product websites that might be useful to owners making feed selections.  

Feeds for Youngsters

When feeding young, growing horses horses (typically up until 2 to 3 years of age) with a product formulated specifically to meet their growing bodies’ needs, it’s important to consider some key figures on the feed tag. First take a good look at your horse’s age, weight, average daily weight gain, etc. and determine his nutrient requirements (this is best achieved by working with an equine nutritionist). You’ll also want to have your hay analyzed so you know what nutrients your horse is already receiving from any hay or other forage you are providing, as commercial feeds are designed to fill that gap.

Then look at the product name and/or purpose statement. It should be something along the lines of “Growth,” “Junior,” or “Foal.”   

From there, look for the guaranteed analysis similar to the one pictured above. A product for growing horses typically contains a fairly high level of protein, which is a major component of body tissues such as muscle, compared to products for other types of horses. Values of 14-16% are common for growing horses. But feeding your youngster a higher percentage doesn’t always mean he is getting more protein.  

For example, if the manufacturer recommends feeding 4 kg (about 8.8 pounds) of a 14% crude protein product, that would provide 560 grams (1.2 pounds) of protein. A recommended feeding rate for a product that has 16% might only be 3.5 kg (7.7 pounds), which would also provide 560 grams of protein. For this reason, when considering what product to use, you’ll also want to read the instructions to see how much you should feed.

Also, because crude protein percentages don’t really give any indication about protein quality, many feeds designed for growing horses are labeled with the amount of lysine (a key amino acid for the growing horse, usually present at about 0.8-1%) or other amino acids, such as methionine and threonine. The AAFCO does not require these to be in the guaranteed analysis, however.

Calorie content, or energy density, is something we’re used to seeing on human food product labels, but you won’t see this labeled on horse feeds. Still, it’s important to equine growth. Fat and fiber content can give you an indication of the feed’s calorie content, though, because fat tends to increase calorie density and fiber decreases it. If a feed is greater than 18% fiber, it might be labeled as a “complete feed,” which means you can feed it without any added hay or other forage in the diet. The fat and fiber content might also hint at the amount of starch and sugar in a product, because when fat and fiber content is high, starches and sugars tend to be lower.  

For a growing horse, the average calcium (between the minimum and maximum values) in the bag should be around 1%, and the phosphorus minimum should be about 0.55-0.65%. This will ensure the horse is receiving sufficient calcium and phosphorus for adequate bone growth. Copper and zinc are also involved in bone and tissue development: Copper should present at 60 to 90 parts per million (ppm), zinc at 150 to 250 ppm. Selenium should be in the feed at 0.3 ppm, but levels might be as high as 0.6 ppm in some products. A growth formula feed’s vitamin A content is typically in the 3,000-7,000 IU/lb range.  

Select a feed whose manufacturer has listed high-quality ingredients on the tag. Quality sources of nutrition for growing horses, such as oats, alfalfa meal, beet pulp, rice bran, soybeans, or peanut hulls, should be near the top of the list. The formulation might contain other seedmeals, such as linseed (aka flaxseed). Different types of vegetable or seed oils will also be listed, which might contain omega-3 fatty acids, along with minerals. Look to see that the ingredients include fat-soluble vitamins A, D, and E, as well as some of the B vitamins (e.g., folic acid) that can be lacking in hay. Many feeds also include yeast products, which some researchers believe benefit the GI tract’s microbial ecosystem and the product’s digestibility.  

How much you feed your young horse depends on his age, weight, and the amount and type of hay you feed. It is important to follow the guidelines as directed on the feed tag. This is because equine nutritionists do a great deal of research to formulate products that meet growing horses’ nutritional demands. If you do not feed your horse the recommended amount of a product, he might not be getting the nutrients he needs.  

Another important feature on the feed tag is the manufacturer. A feed designed by a large equine nutrition company likely has experienced PhD nutritionists on staff to develop and formulate its products. Most companies have well-trained feed representatives who can come to your barn, look at your horses, and help you select the best feed for each. This is very important for young, growing horses, as rate of weight gain and a smooth and steady growth curve are important for preventing orthopedic diseases such as osteochondritis dissecans (bone fragmentation to the point the bone is loose), physitis (growth plate inflammation), or osteochondrosis (abnormal cartilage ossification, or hardening into bone). Many feed representatives have scales they can bring out to your facility periodically to weigh your youngsters. The company’s safety standards and reputation can also help you choose which feed is best for your growing horse.  

Take-Home Message

Working closely with a feed company representative or private equine nutritionist is important, particularly if you’re managing growing horses. In many cases you can prevent accelerated growth rates and resulting developmental orthopedic diseases simply by providing appropriate nutrition. Calorie (energy) intake greatly influences a young horse’s rate of gain, but remember that calories are not listed on equine feed labels. Therefore, while your feed tag is there to help guide you in your product selection and to tell you what nutrients and ingredients are in the bag, you might also need to seek professional advice.