Conversations From Across the Pond – Adjusting Diets for Your New Horse

Following SICAB, many Americans find themselves in the process of importing a new horse from Spain. Guest contributor Coby Bolger, a long-time equestrian, professional nutritionist and resident of Spain, provides some helpful advice.


An equine nutritionist is always at the orders of the rider and the veterinarian of the particular horse in question.

Saying that, after 18 years working as an equine nutritionist, coordinating the diets for the top equine competitors in Spain, I have found that it is important to contribute a calming voice of reason in a cacophony of marketing promises that are the reality of today’s horse feed world.

Simply put, riders are being inundated with messages that they can greatly increase their horse´s performance by using this or that product. They are also being told that certain feedstuffs are “dangerous” and that they are putting their horses at risk.

In general, nutritional training for professionals is embarrassingly weak, to the point that most riders do not know how to read or interpret a feed tag in relationship to their horse’s requirements. Another problem is that riders do not have easy access to science based, non-commercial nutritional information.

As with our own diets, we are becoming knee-jerk reactionists and much prone to commercial manipulation.

I am often called to work with riders who have a horse that has been exported from Spain to the United States, Mexico, Colombia, Korea, or other countries in Europe, to ensure a trouble-free adjustment with the new owner. My conversations over the years, have been with many different riders who practice every sort of equine discipline.

Time and time again, I find myself navigating rider angst and basic nutritional misconceptions.

What should riders know about adjusting a diet for a newly acquired horse?

When you import a horse, know what the original diet was and try not to make major changes for at least 1 month – If you have a bought a horse, it is because you like him. (Obviously, I am speaking here about quality horses for competition or breeding, not rescue horses.)

Part of what you like about the animal, has to do with the work and the diet he received. I see riders quickly introduce radical changes to horse’s diets and management, thinking they are doing a better job than what the original rider was doing.

Often, there is a big surprise when the horse’s character and way of going changes completely and not in a good way.

You need to do a diet evaluation to understand what the horse was eating and look for something similar in your own market. It is also beneficial to know how the horse was worked. This is where an equine nutritionist can really help.

The diet evaluation should include:

  • Total amount received
  • Did the horse receive cereals, which ones and how much
  • Were the cereals cooked or manipulated with heat, soaking or grinding or some other way?
  • How many times a day did the horse receive a grain ration?
  • Did he receive a commercial feed product – Which one and how much per day?
  • Amount, type and quality of the forage
  • Did he have straw bedding?
  • Was he regularly turned out? In what size paddock and for how long? Was there fresh grass present in the paddock?
  • How about supplements? What did he receive?
  • Was the diet balanced according to a least NRC or INRA levels

If the diet was poor and did not respect NRC minimums, adjust the nutrient levels without going crazy. But don’t radically change the starch and oil content of the diet. That will affect your horse’s character and physical form.

When working with a rider, I like to use the terms “open your hand” to slowly adjust up in nutrient contents and calories or “close your hand” to adjust down. It suggests that feeding is not a precise science, but all about knowing your horse and how he reacts to different feeding regimes.

If the horse is on the thin side, you can increase the total ration to 2.2% of his body weight by introducing more hay. If he is a bit chubby, move toward a total ration of 1.8% total body weight and give him a little poorer quality hay. And then quietly get to know your horse.

If you are in danger of falling off, lower the starch content a bit and lunge him before you get on. Or pay a professional rider to keep the horse on the right track. I will occasionally even have the horse sleep outside in a small paddock if possible. There are plenty of options, but good horsemanship and experience is key.

I like to have an initial visit with the vet just to get the horse off on the right foot. A control blood test always comes in handy to evaluate your new horse’s form over time.

Don’t plan an aggressive competition schedule before you have had a chance to acclimatize the horse. Take 2 months to evaluate the horse. See how fit he is, how social he is, get him accustomed to your transport habits and take him around to local shows. As you get to know him, you can transition into a correct diet for both your stable management and his requirements.

Pay attention to the hay quality he received before and don’t think you are doing him a favor by radically increasing the hay quality or quickly introducing green grass into the diet. Many horses bred in Spain, especial in the Madrid or in Andalusia have no access to green grass, and this major change can initially create havoc with their intestinal flora.

Don’t be afraid of oats. Unprocessed oats (cleaned of course) are highly digestible and have the lowest starch content of all the cereals. If the horse has received oats his whole life, you only need to add in a balancer to bring the protein, vitamin and mineral content up to snuff.

If he was receiving an oat and straw based diet, by all means balance the diet with a balancer and kick on.

High oil diets are not for every horse – there has been a relentless onslaught of marketing messages that high oil diets are better for horses. While this is true for horses for Endurance horses or horses with certain metabolic problems like insulin resistance, RER or PSSM, most horses do not need a high oil diet. Oil is a calorie source, so horses that have the tendency to gain weight easily should move towards a lighter ration.

Low starch diets are not for every horse – Kentucky Equine Research did an informal study on starch content of equine diets during the Lexington WEG. In general, the European horses were managed on higher starch levels than the US competitors.

Starch gives “sparkle”. If you are hanging off the lights of the indoor school because your thoroughbred bucked you off, don’t give a high starch diet. But if you are wearing a huge spur and want your Andalusian PRE to have the “WOW FACTOR” while you are going down the center line, give him some starch.

Nutrition is not that complicated. You need to manage your horse’s feeding so as to prevent digestive upsets like ulcers, colic or laminitis. Then you need a clear understanding of the nutritional requirements of your horse and how different feedstuffs available to you contribute to getting your horse to the proper nutrient levels. Once you combine these requirements successfully, you can start to think about the million other variables to guarantee your horse’s success.


_MMM7758 By Coby Bolger – Equine Nutritionist – Spain

Coby Bolger, originally from Virginia, is the managing director and founder of Horse1, Equine Nutrition Centre in Madrid, Spain. Coby spent 5 years in England eventing at an international level, gaining dual Spanish/US citizenship in 1998, winning the Spanish National Eventing Championships in 1999 and 2000 and representing Spain at numerous international events including European Championships and World Equestrian Games. Coby continues to ride, write, teach and generally “give back” to the equine world, as any dedicated horseperson would do.

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