Feeding Options For Problem Horses
By Dr. Katie Young, Equine Nutritionist, Purina Mills, LLC
Part 1 – Underweight and Overweight Horses
As Dr. Leo Eldridge, one of our Purina research veterinarians at the Research Farm, says, “If you have a horse, you have a problem.” Of course, as a horse owner myself, I am well acquainted with this philosophy! And, according to Murphy’s Law of Horse Ownership, the more you spent on the horse, the bigger the problems will be.
As a nutritionist, I’d like to be able to say that we can fix most problems by feeding the horse correctly. Unfortunately, in many situations all I can say is once we’re feeding the horse as well as we can, then we have to look for different solutions to address the issues. However, there are some situations in which nutrition can solve the problem, or at least help manage the problem. For instance, nutrition can often help with underweight and overweight horses, and sometimes proper nutrition and management can improve the situation with horses that are susceptible to colic and/or founder, or have problems with tying-up, gastric ulcers, or Cushing’s Disease.
Underweight Horses
I am often asked questions about putting weight on a thin horse. My initial reaction is to try to determine why the horse is thin in the first place.
When dealing with a thin horse, first we need to look at the horse’s health status. Is the horse suffering from parasites, disease, chronic pain, or dental issues? These are all issues to be addressed by the veterinarian.
Another possibility is that the horse is getting old enough that its teeth are no longer adequate to chew long-stemmed hay. Hay is very fibrous, and as a horse ages, its teeth wear down to the point that the horse is unable to fully chew the hay, and, also with age, the horse’s digestion and absorption in the gut becomes less efficient. Therefore, what hay and feed does get fully utilized. In these situations. I recommend feeding Purina’s Equine Senior. Equine Senior was designed to contain enough roughage to be fed with no or minimal hay, so that the geriatric horse can get enough nutrients to meet its requirements without being able to chew adequately. The horse should be gradually switched from the current feed to Equine Senior, and then the amount of Senior will be gradually increased to compensate for the roughage the horse is unable to eat. There will come a time that a geriatric horse will not be able to utilize hay whatsoever, and will need to obtain all its nutrients from Equine Senior. For this reason it is not uncommon to feed 15 or more pounds per day of Equine Senior, especially if the horse is working. If the time comes when the horse’s teeth are such that the horse is no longer even able to chew the soft pellets, then water can be added to the Equine Senior to make a mash. (Note: the age at which a horse becomes a Senior is determined by the horse. Some horses need to be fed Equine Senior in their teens, others will do fine on Strategy or Omolene 200 and grass or hay well into their twenties.)
In most cases, the reason a horse is underweight is that if is just not eating enough calories. So, to put weight on a horse, first you need to determine how much the horse currently weighs and how much weight it needs to gain. An easy way to determine the horse’s body weight is to use a weight tape. Purina spent seven years measuring horses at the Research Farm to develop their body weight tape, which is available through your Purina Mills Dealer. Be sure to read the directions on the tape, measure around your horse’s heartgirth (running the tape just behind the horse’s withers) and determine the current weight. To decide how much weight the horse needs to gain, you need to condition score the horse. In general, most horses should be at a body condition score (BCS) of 5; broodmares should be 5 to 7. ABCS of 5 is a horse that you can look at from the side and not see any ribs showing, but if you run your hand along the barrel you can easily feel the ribs. For more information, go to the Purina Mills website (horse.purinamills.com, click on Body Condition Scoring Chart).
For every condition score below 5, the horse needs to gain about 45 pounds, and a 1-pound gain requires about 8000 kcals over the calories required for maintenance. So, for example, it the horse needs to go from a 4 to a 5, it needs to gain 45 pounds, which is a total of 360,000 kcals. Obviously, we’re not going to feed that in one day! It is safest to put weight on a horse slowly, so let’s take 90 days for this example. 45 pounds of gain in 90 days is_pound per day, a safe goal to aim for. About 4000 additional kcal per day over the normal amount fed should achieve_ pound of grain per day. This could be accomplished by adding 2 lbs of Strategy (3000 kcals) and 1 ob of alfalfa hay (900 kcals) per day. Asin all cases, changes need to be made gradually to reduce the risks of digestive upsets.
Overweight Horses
There are a few pathologic causes of obesity, but usually the cause is simply over-feeding. Beauty is in the eye of the beholder, and many horse owners prefer the look of a horse with quite a bit of “bloom.” We also tend to enjoy the reception we get from our horses when we bring them more food – they love us! However, horses that carry excess weight are more proce to health problems. For instance, some researchers believe that obese horses are more likely to develop Equine Metabolic Syndrome (Peripheral Cushing’s Sydrome), which may lead to serious health problems.
It the horse is obese (body condition score 8 or 9), the answer is to cut calories and increase energy expenditure. Again, you need to determine the desired weight of the horse by using the body weight tape and body condition scoring, and then feed 65-70% of the calories needed to maintain the horse at the desired weight. To calculate the digestible energy (calorie) requirement, use the following equation:
DE = 1.4 + (0.03 x BW), where BW is the horse’s desired weight in kilograms (1 kg = 2.2 lbs).
To meet the calorie requirements for losing weight, the horse owner can feed lower calorie feeds such as grass hay with Purina’s Equine Adult or a concentrate such as Nature’s Essentials Born to Win (a concentrated source of protein, vitamins and minerals).
Example: 1100 lb horse
1100 divided by 2.2 = 500 kg
1.4 = (0.03 x 500) = 16.4 Mcals (or 16,400 kcals) per day required for maintenance
70% of 16,400 kcals = 11,480 kcals per day for weight reduction
Possible ration:
12 lbs grass hay (12 obs x 800 kcals/lb = 9600 kcals)
1 _ lb Born to Win (1.5 lb x 1300 kcal/lb = 1950 kcals)
Total – 9600 kcals + 1950 = 11,550 kcals per day
Of course, increasing the horse’s workload will also help the horse lose weight by increasing its use of calories. Ideally, again, the horse should be maintained at a body condition score of about 5. This allows the horse adequate energy stores for maintenance and work. If the horse is a broodmare, she should be maintained at 5 to 7 BCS for optimal reproductive performance.
In future articles, I will address nutritional management in situations such as colic, founder, tying-up, gastric ulcers, and Cushing’s Syndrome.
