Beet pulp is a nice halfway point between grain and forage---it`s lower in soluble carbohydrates than grains are and is high in pectin, which is a form of soluble fiber. Therefore, when digested by the horse, it provides a steady, slow rise of blood glucose for a long period of time---a good thing for an endurance horse with a long day ahead of him. This is as opposed to highly soluble carbohydrates, to one extent or another, such as grain or sugars. Depending on the exact type and content of the sugar molecules, glucose enters the bloodstream much more quickly and pretty much all at once. The blood glucose levels rises much more quickly and to a higher level, but then also drops much more quickly, potentially leaving the horse with low blood glucose levels while he still has many miles to go. The trick is to choose the correct form of carbo for the type of exercise your horse is performing---a higher blood glucose level is more applicable for racehorses (Tom, jump in here), while a slower, sustained glucose level is usually preferable for slower, sustained (endurance) exercise.
Soaked beet pulp is also a good way to get a little more moisture into your horse during a ride. Beet pulp easily holds water at a 2-3 to 1 ratio (a cup of beet pulp will soak up 2-3 cups of water) and that`s a nice reservoir of extra moisture to have in a horse`s gut on the trail. Beet pulp is also fairly high in fiber which will help maintain gut motility during a ride.
Also, while beet pulp is higher in energy than any hay, and is considered right on the borderline between being a forage and an energy feed, it does not have the risks of causing laminitis, azoturia, or acid-base disturbances that grains (highly soluble carbohydrates) do. It won`t upset the microflora bugs in the gut like soluble grains can. Horses that get silly on grains but can`t maintain weight on hay alone often do very well on beet pulp---and, as an Extra Added Bonus, beet pulp is a terrific base for adding fat to a horse`s diet, which has a bunch of advantages for endurance horses all it`s own.
The calcium-phosphorus ratio of beet pulp is just fine, it doesn`t have outrageous levels of any nutrients that contribute to Bad Things (like enteroliths, inverted ca-p ratios, etc) and it`s a nice source of quite a few of the macro and microminerals. It`s low in overall protein at 8.9% but has a better lysine content than any of the non-oilseed grains. It makes a terrific base for mixing in other supplements like probiotics and 15 mg a day of biotin, WHICH YOU ARE FEEDING, RIGHT????
It`s cheap and a little goes a long ways---it`s like that Instant Pudding scene in "Sleeper". Put a tablespoon in a bucket with water and the next morning you`re knee deep in soaked beet pulp, enough to fill your average Honda. I found that out the hard way the first time I filled a five-gallon bucket with beet pulp, added water and walked away. The next morning, I had to use a snorkel just to get into the feed room, and all the horses within a five-mile radius had a breakfast they still recall with great affection.
The down sides to beet pulp---if you`re looking for absolute maximum calorie density, this isn`t it. The energy level is 2.33 Mcal/kg, which is higher than any of the hays, including alfalfa, but is lower in energy than any of the grains such as oats, barley or corn at 2.99, 3.26 and 3.38 Mcal/kg, respectively. And lots lower than vegetable oil at 8.89 Mcal/kg. So you have to look at your own circumstances at decide where beet pulp fits into your feeding program.
More down side---it`s annoying to always be setting out beet pulp at night to soak, unless you`re a closet nutrition type that gets cheap thrills from that sort of thing. You can`t mix it up in five minutes like you can other dry feeds, and it will start to sour if you leave in the sun for too long. Lots of people feed beet pulp dry without soaking it and never have problems, but since George of the Jungle is determined to kill himself in New and Unusual Ways before he ever hits two years old, I try to keep potential weapons away from the imbecile.
Bottom line on beet pulp is that it`s a very safe way of getting extra calories into a horse either between rides or during a ride without some of the disadvantages of grain.
Hope this answers your questions.
Susan Garlinghouse, BS An. Sci.,almost MS
and Recovering Closet Nutrition Type