Pound for pound, which has more calories, beet pulp or alfalfa? I know there would be some variation due to hay quality, but I am looking for an average. I am trying to put weight on a thin Thoroughbred and have been giving him alfalfa pellets and beet pulp pellets in addition to 15-17 hours a day of lush pasture. He also gets one to two cups of canola oil and two pounds of a ration balancer. The gelding is a cribber. Blood work revealed slight anemia but no thyroid issues. The gelding just arrived here two months ago, and he still seems lethargic with little appetite.
In response to your question on the difference in energy density between alfalfa pellets and beet pulp, there is little. The primary difference is in how they are fed. If you take the average digestible energy of alfalfa pellets at 1.092 Mcal/lb (range is from 0.933 to 1.191 Mcal/lb)* and compare it to beet pulp at 1.199 Mcal/lb (range is from 1.105 to 1.293 Mcal/lb)*, it would seem that beet pulp is more energy dense, although only slightly (only 0.1 Mcal/lb). These numbers, however, do not take into consideration moisture content. Beet pulp is usually fed wet after being soaked in water, so if you compared the wet beet pulp to the dry alfalfa pellets the amount of energy in the beet pulp would be less because you would factor in the water that adds weight (but not calories). If you fed the same amount in dry weight, the caloric density would be about the same. Both feedstuffs are good sources of fiber energy and work well for putting weight on hard keepers, especially the ones that are not very good at eating hay or grass.
For this Thoroughbred, I would say a combination of the feedstuffs is a good idea as long as neither of the two is unpalatable to the horse. If the horse is recently off the racetrack, he may be very accustomed to eating large amount of grains and not nearly as much roughage as you may be offering. It may be a matter of time before the horse settles down into his new home and develops an appetite for different types of feed.
There are other factors with ex-racehorses that have an influence on appetite as well. Most racehorses have ulcers (surveys suggest over 90%), and it takes time for them to heal after leaving the track. Having the horse out on pasture most of the day is one way to give the stomach time to repair itself, but it will take longer than two months. You may consider giving him a supplement like RiteTrac that will prevent him from developing new ulcers by providing a healthy gastric environment. Another recommendation is to include some alfalfa in the diet, which has been shown to reduce severity of ulcers. You have been doing this, but the horse has to be willing to eat the alfalfa. Since the horse is new to your farm, even if it is not off the track, and it does not have much appetite, I would suspect ulcers because of the change in environment. Anemia is seen in horses with bleeding ulcers.
Another issue can be hindgut acidosis or an imbalance in the microbial population in the hindgut, which will make it difficult for the horse to put on weight. When this occurs, we often see the appetite affected because the horse is not comfortable. Hindgut acidosis is often relieved by a supplement that includes a hindgut buffer like EquiShure. A supplement that corrects microbial imbalances would be a probiotic or a yeast blend like Triad.
Another problem with ex-racehorses is the possibility of steroid use, and withdrawal from steroids can be pretty hard on certain horses. It takes some of them about a year to come around and settle into a new program.
It looks like you are trying to stay away from starches with this horse by feeding a lot of roughage and oil for calories, and balancing it out with a balancer pellet, but sometimes a horse will actually gain weight faster with a little starch (particularly Thoroughbreds). If he does not come around with the current diet, you have a couple of options: (1) offering some oats in addition to what you are feeding (it may perk up his appetite); (2) mixing some of a commercial feed into the beet pulp/alfalfa pellet mix to make it more palatable; or (3) using a commercial feed and feeding it at the recommended feeding rate instead of balancer.
* This data is from Equi-Analytical.com, and the averages are from 408 samples of alfalfa and 637 samples of beet pulp.
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