“Managing equine growth is a balance between producing a desirable individual for a particular purpose without creating skeletal problems that will reduce a horse’s athletic ability,” said Clarissa Brown-Douglas, PhD, a nutritionist for Kentucky Equine Research Australia.
She noted that managers should be familiar with equine growth patterns, and she guided attendees through the first few years of a horse’s life, discussing ideal feeding techniques and key points to remember.
Equine Growth Patterns
Study results have shown that when the average horse is born, he weighs about 10% of his mature weight, Brown-Douglas said. She explained that horses grow quickly during the first year of life, reaching 43% of mature body weight by 6 months of age and 61% of mature weight at 12 months. By the time the average horse turns 2, he weighs about 96% of his mature weight.
Researchers have also revealed that growth rate can be influenced by factors including birth month (foals born earlier in January were significantly smaller at birth than foals born later in the spring, but gained more weight than the latter group at 3 months of age), weaning (growth rates slowed at weaning time, but increased the following spring), and sales preparation (growth rates can increase when young horses are being prepared for sales, depending on the animal’s diet).
Feeding Young Horses
At each stage of a growing horse’s life, he’ll require different feed sources and nutrients to help him stay strong and healthy.
Brown-Douglas said foals receive 100% of their nutritional requirements from their dams’ colostrum and then milk during the first month or so of life. An average Thoroughbred foal, she said, will consume about 15 kilograms (about 33 pounds) of milk daily. After the first few days, foals will likely start nibbling on grass, she said, after watching and learning from their mothers.
A foal will sometimes nibble on the dam’s grain rations if she allows and, as mentioned, will consume grass and hay, but he won’t require supplementary feed rations until he reaches about 2 months of age. At this point, Brown-Douglas suggested providing the foal with creep feed, which provides additional nutrients needed for growth.
Select a creep feed designed for growing horses, feed according to label instructions, and ensure the calcium:phosphorus ratio is appropriate, she stressed. Additional keys to creep feeding success, Brown-Douglas said, include:
- Good feeder placement: Ensure the mare can’t access the foal’s feeding bin, but select a location that’s easily accessible for the growing horse.
- Allow time to eat: Foals will consume their creep feed at different rates. Ensure each foal has adequate time to consume the nutrient-dense feed.
- Try the ‘Buddy System’: Brown-Douglas noted that foals might be more apt to eat well if accompanied by other foals. If possible, let foals creep feed in company.
Researchers have also determined that creep feeding is associated with lower weaning stress in foals, Brown-Douglas said.
When foals reach weaning age, nutrition becomes of paramount importance as this is the age when the skeleton is most vulnerable to developing disease or disorders, Brown-Douglas relayed.
At weaning age, horses are most prone to developing developmental orthopedic diseases (DOD), such as osteochondritis dissecans (OCD) or wobbler syndrome. While these disorders might have a genetic component, Brown-Douglas said that nutrition does play a role in DOD development. Feeding to prevent and manage DOD was discussed in a subsequent lecture, but Brown-Douglas provided some tips for feeding the weanling:
- Ensure the weanling is consuming an adequate amount of vitamins and minerals, and ensure mineral ratios (such as calcium:phosphorus) are balanced properly. She said the best way to achieve this is through a ration evaluation, as blood, hair, and hoof analysis won’t be useful in evaluating mineral levels.
- Avoid feeding weanlings too many calories. Studies have shown that heavier foals have a higher incidence of OCD than thinner foals. Brown-Douglas said there’s no simple rule that dictates how much a weanling should be fed, but suggested weighing and determining body condition score of weanlings on a regular basis to ensure they’re not gaining too much weight.
- For overweight weanlings, choose grass hay over alfalfa.
- Choose a concentrate designed for growing horses, and feed according to label directions to ensure the weanling consumes the appropriate amount of nutrients from the grain. Avoid feeding straight cereal grains or food designed for mature horses.
- Choose a feed with lower glycemic energy sources (high fiber and oil, rather than high starch from cereal grains) as a high glycemic response to a meal has been implicated in the pathogenesis of DOD.
Brown-Douglas said protein does not appear to play a role in DOD development and, in fact, is vital for sound growth and development. If horses are showing signs of excess body condition and DOD, reduce the energy in the diet but not the protein.
By the time foals reach 12 months of age, the are less likely to develop DOD, Brown-Douglas said. Continue monitoring growth carefully and avoid overfeeding. Conduct ration evaluations to determine correct nutrient and mineral balance and to ensure the yearling’s nutritional needs are being met.
Brown-Douglas advised basing the yearling’s diet on forage and supplement with a concentrate designed for growing horses. She recommended designing a feeding schedule for each individual yearling. For example, “easy keeper” yearlings shouldn’t be allowed to become too overweight, as mentioned previously. Brown-Douglas recommended a low calorie balancer with concentrated levels of essential protein, vitamins and minerals for these horses. On the other hand, yearlings that still have room to grow should consume “normal amounts” of fortified feed, she said.
Although it can be a challenging balancing act, feeding growing horses can be successfully achieved by remembering to aim for steady growth rates, to avoid overfeeding, provide horses with low glycemic energy sources, feed adequate protein, and base the diet on forage. If questions or concerns arise, consult an equine nutritionist or veterinarian.