Feeding the Young Horse
Good nutrition is important with any age of horse, but it’s probably never more important than during the first few years of life. Poor nutrition can lead to stunted growth, and dietary imbalances, nutrient deficiencies, and likewise, overfeeding, can also lead to Developmental Orthopedic Disease. For growing horses, finding a nutritional balance is key.
A young horse’s diet should be based on high-quality forages with grains added as needed to provide a concentrated source of energy, protein, vitamins, and minerals.
Of course, I’m a fan of forage-based feeding and have written about studies which concluded young horses can do well on forage-only diets, but the only way to know if your pasture/ hay is sufficient in protein, minerals, etc. is to have it tested.
After four months of age, a weanling’s nutrient requirements will exceed what can be provided by a mare’s milk. If he’s already on pasture, then eating grass will be a natural behavior, but if not, then supplemental hay and possibly concentrates ( via creep feeding) are in order.
High-quality protein is crucial for muscle, ligament, and tissue development. According to this article by Kristin Janicki, MS, PAS, “Most young horses that should mature to around 1,100 pounds will need about 675g of protein per day when they’re around 6 months old.”
With weanlings, careful attention should be paid to the minerals, calcium, phosphorous (Ca: P ratio should be 1:1 to 3:1) zinc, and copper (Zn: Cu ratio should be 3:1 to 4:1). Keep in mind that if you are feeding a legume hay, they are typically higher in calcium. Grains are higher in phosphorous. So any changes with either of these ingredients will also change your Ca: P ratio. Trace minerals may need to be provided in the form of a supplement or pre-formulated concentrate.
It’s important to feed each weanling as an individual to achieve a steady rate of growth. If you notice he’s growing too quickly or slowly, adjustments should be made in the diet.
The diet shouldn’t change much from weanling to yearling, but their growth rate does slow some by the time they reach a year old. Around 15 months of age, horses should reach 90% of their full height, 95% of their mature bone length, and 70% of their adult weight.
If yearlings are on good pasture in spring and summer, this may be all they need to continue their moderate growth rate. Continue to pay attention to the Calcium: Phosphorous ratio though (have pasture tested) and supplementing trace minerals may still be necessary. During the fall and winter, as well as in times of drought, supplementing with good quality grass hay and some legume hay (such as alfalfa) is needed.
If they aren’t on green pasture, adding supplemental fat such as flaxseeds, chia, flaxseed oil, or camelina oil can also be beneficial to add around this time. As with any dietary change, introduce your fat source slowly.
Your yearling should be gaining around 1.25 pounds (450-600 grams) daily until he’s reached around 18 months of age.
Two and Thee-Year-Olds
By this age, your young horse’s nutrient requirements have declined, but he isn’t quite finished growing yet. Again, forage should be the cornerstone of the diet, and concentrates only fed as needed. You can now feed your horse closer to what you feed your adult horses, again tailoring each diet to the individual horse’s specific needs. If your two or three-year-old is in training, his nutrient requirements will increase. There is also some new evidence suggesting joint supplements can help prevent problems before they develop in young horses. It’s definitely something worth checking into.
A key piece of information to keep in mind when feeding young horses is to feed small meals and often. Young horses have small stomachs which cannot handle large meals. And like all horses, they should not go for long periods of time without food–this will only increase the risk of ulcers and colic. Please remember to make ALL feed changes slowly, over a period of 7-14 days.
For help in determining your horse’s specific nutrient needs, I recommend using the National Research Council’s calculator.
Sources and Further Reading