A little over a year ago I received the following email.
"I have a 4 year old 17.2 hand Dutch warmblood gelding. He had OCD surgery as a 2 year old, and colic surgery as a 3 year old, and then suffered another colic 3 months post-op. He has chronic diarrhea/loose stool, and I have a difficult time getting him to pick up weight. I have tried just about every kind of treatment, and nothing really seems to work. I put him on a grass hay only diet after the colic, but I can't keep weight on him with it. Do you have experience with horses like this?"
This sounded like a very interesting case but I was curious to find out more about his colic’s and his diet overall. His owner sent me some further information.
He had the colic surgery for an impacted and displaced large colon. Both times that he coliced, he was out of her care, off being started under saddle. The first colic, there was a feeding instruction misunderstanding, and they had him on a diet of 100% alfalfa (6 flakes a day)...he ended up with terrible diarrhea, and then the colic. After that colic, she took him off of alfalfa completely, and the only other hay offered at the barn was a 3 way mix (oat, rye, wheat). He was fine on it at home, but again, when he went back to training, he coliced again. Both times he coliced within a week to 10 days of being at a new barn.
Since the second colic, he had been home with his owner, and absolutely fine besides being a very hard keeper. He was on all grass hay getting about 36lbs a day, but he just wasn't interested enough in it, and was leaving a lot, so it had been cut back to 24lbs a day, and he was still picky about it.
She went on to mention:
I've had to add a horrifying amount of supplemental feed to his diet because it's all that I can get him to eat. I'm really not all that comfortable with how much I'm having to give him. He is currently getting around 16 pounds of a 12% fat performance feed a day, plus 2 cups of corn oil in addition to the hay. He also gets a joint supplement, an electrolyte recommended by the vet after the second colic, and a digestive tract support supplement.
So, where to start? One of the first things I do with a new horse is to estimate its current weight, body condition score and the energy in the current diet. This allows me to calculate requirement and compare it to the current diet and using the body condition estimate whether the energy in the current diet is adequate to maintain body weight. This horse was estimated to weigh 1350lbs and to have an energy intake of 52 Mcal of digestible energy a day from his current diet, and his requirement for the level of work he was doing was only 28.5Mcal. With this amount of energy intake he should have been super fat yet he condition scored between a 4 and a 5, mildly under weight. Something was not right and the fact that he always had loose stools made me suspect that for some reason his digestive tract was not working optimally, specifically his large intestine. This would also explain why he was picky about eating the grass hay. It certainly sounded as though moving to new locations and different management styles had caused the horse some stress which had maybe caused some digestive distress resulting in colic.
Horses with gastric ulcers tend to go off grain and when the large intestine is disrupted horses will become picky about hay because the large intestine is where hay is digested. 16lbs of a fortified feed is a lot of feed unless you are feeding a complete feed and no hay. Based on the feeding directions for the high fat performance feed 16lbs was likely the maximum for his size and I wondered whether the high fat might be disrupting fiber digestion especially with the additional oil that was being added. Each horse has a different rate at which feed passes through its digestive tract. A horse with a higher rate of passage will be at greater risk of undigested feed reaching the large intestine. Feeds with high starch or fat contents that reach the large intestine can disrupt the bacteria and fiber digestion. With the added oil I thought that the level of fat in his diet may have been too great for him. My sense was we needed to remove some of the fat and work on supporting fiber digestion so that he would eat more grass hay and be able to derive more nutrients from it resulting in more weight gain, while hopefully firming up his manure.
Beet pulp is a highly fermentable form of fiber. It requires microbial digestion in the large intestine but pound for pound results in a similar amount of energy as oats. As a result it can be very helpful for getting weight on horses without the need to feed large amounts of grain that are high in starch and sugar. I did not want to rely too much on grain as an additional calorie source for this horse as he had a history of OCD and was still young, plus his digestive system already seemed upset and I didn't want to risk grain, at least not initially.
While the owner was wary of adding alfalfa due to the colic that had occurred when he had been fed alfalfa I felt that a small amount of alfalfa in the diet would be beneficial. Alfalfa is high in calcium and in cattle there has been some research that has shown that calcium reduces the negative impacts of fat on fiber digestion. Additionally, there has been some research suggesting that alfalfa may help to reduce the risk of ulcer development and it is a slightly better source of protein than grass hay which might help him build muscle. The initial plan was to gradually wean away from the high fat performance feed and replace it with beet pulp and to replace one flake of grass hay with a flake of alfalfa.
His owner started him on a small amount of alfalfa and right away saw an improvement in his manure. 4 days later I received an email,
"Just a quick update to let you know that his manure is the best that it has ever been! The only thing that I can think to attribute it to is the addition of alfalfa to his diet. I noticed a change almost immediately. "
This assured me that we were taking the right path. Over the next month we removed the high fat feed and introduced wheat bran to add more phosphorous in order to balance the calcium in the beet pulp. We eventually added oats to further increase the energy in the diet and a custom selected mineral supplement to insure the diet was correctly balanced. Overall the new diet provided 38Mcal a day, a 14Mcal decrease and yet he was gaining weight and had a much healthier digestive tract.
Sometimes making a diet for a horse is not as simple as clearly saying “you should feed x,y,z.” In some situations like this one you need to be willing to experiment and see what reaction you get, as we did with the alfalfa. The feedback you receive from the horse can help you to fine tune the diet further. Implementing a successful diet in this kind of situation takes team work, patience and trust.
If you have a tricky nutritional case that you would like help with please do not hesitate to contact us.
16lbs of Grain and Still Losing Weight by Clair Thunes PhD of Summit Equine Nutrition LLC is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.