beet pulp article, Part Two

["Susan Evans Garlinghouse" <suendavid@worldnet.att.net>]

Here's the other half...

 

Susan G

 

Myths and reality about beet pulp for horses (Part Two)

Susan Garlinghouse, MS

    Other than avoiding Rocket Rides, what difference does the glycemic index make? High-energy feeds like corn are still a more concentrated source of calories than beet pulp, right? Yes, they are—however, high-glycemic feeds such as corn and other cereal grains are also much more likely to cause nutritionally-related disorders such as colic, founder and polysaccharide storage myopathy. For these reasons, highly soluble carbohydrate sources must be fed in relatively small and carefully managed amounts to avoid intestinal upset. In contrast, the energy in beet pulp is primarily derived from both soluble and insoluble fiber—energy which must be released through microbial fermentation in the cecum and large colon, as is the energy in other forage feeds such as hay. While hays can contain varying amounts of insoluble fiber, which affect its digestibility and energy content, a significant portion of the fiber in beet pulp is in the soluble form of pectin—the same substance that solidifies fruit juice into jelly. Pectin is still processed in the cecum, but is highly digestible and easily broken down to useable energy by the microbial flora. Since beet pulp does not contain large amounts of soluble carbohydrates which may cause intestinal upset, it can be safely fed in much larger amounts. Therefore, although beet pulp contains somewhat less energy on a pound for pound basis than grains, it can provide more total calories to the horse when substituted for part of the forage portion of the ration, or used to extend and "dilute" a meal of grain. Although lower in fiber than most hays, beet pulp can be used to replace up to 50% of the forage portion of the ration—a feeding strategy which can significantly increase total calories without increasing the risk of colic or founder.

    Contrary to popular belief, while beet pulp can be soaked prior to feeding, it does not have to be. In fact, in many management situations, feeding beet pulp dry is preferable. Horses consuming soaked beet pulp in hot weather may be unable to finish off a large portion before it begins to sour and becomes unpalatable. Likewise, horses in cold climates may not be able to finish their soaked beet pulp before it begins to freeze. Research conducted at several universities have fed dry beet pulp in amounts up to 45% of the total diet and saw no instances of choke or other adverse reactions. Although beet pulp, particularly that in the pellet form, can cause choke, the choke is more in response to the particle size and the horse’s feeding behavior than due to the actual feed itself. Horses which bolt their food without sufficient chewing, or do not have adequate access to water, are far more likely to choke regardless of the type of feed than horses which eat at a more leisurely rate. Efforts should be made to prevent gobbling in these "wolfers", such as putting rocks into the feeder. If all else fails, then feeding only soaked beet pulp may be the only alternative.

    Many horse owners are also concerned that due to the amount of water that beet pulp soaks up, and the volume that it expands to, a large meal of dry beet pulp will somehow cause the stomach to swell up and rupture. A simple explanation of the equine stomach will allay this particular concern. The capacity of the equine stomach is 2-4 gallons, equivalent to approximately 4 ½ to 9 ½ pounds of dry beet pulp. Movement of food from the stomach to the small intestine can vary depending on a number of factors, but as the stomach begins to reach maximum capacity, stretch receptors in the walls of the stomach will trigger the release of motilin, a hormone which in turn stimulates the emptying of the stomach and passage of food into the small intestine, cecum and colon. As the capacity of the gastrointestinal system—approximately 38 to 48 gallons—is more than sufficient to adequately contain even a very large meal of beet pulp (or any other feed), the only horse in danger of a gastric rupture is one suffering from impaction or other severe lack of normal peristaltic movement.

    Concerns about beet pulp "pulling water from the blood and into the stomach and causing dehydration" are also unfounded. Regardless of the type of feed, horses will generally drink 3 to 4 liters of water for every kilogram of dry matter consumed (dry matter is what’s left over in a feed after its own moisture content is disallowed). Assuming free access to clean, fresh water, horses will voluntarily consume enough water to adequately process any amount of beet pulp consumed. If soaked beet pulp is provided, drinking will be proportionately less as the moisture content of the soaked pulp supplies considerable water. In either case, fluid shifts of moisture from blood plasma to the interior of the gastrointestinal tract will not be significantly different from those occurring with any other type of feed with similar moisture content.

    Aside from its energy density, beet pulp is also a relatively good source of calcium. Though not as high in calcium as alfalfa at 1.2%, beet pulp is still a good source at .62%—higher than any other commonly fed horse feed except for dehydrated milk. In addition, beet pulp does not contain excessive protein as does alfalfa. This adequate, but not excessive, level of calcium makes beet pulp a useful supplement for horses being fed a grass or cereal grain hay diet. Although most grass hays contain an acceptable ratio of calcium to phosphorus, orchardgrass, some grain hays and even individual crops of normally balanced hays can be slightly inverted below recommended levels. In addition, rations containing significant amounts of grain or bran can further create imbalances. By including several pounds of beet pulp as part of the daily ration, horse owners can supply an additional source of calcium to help ensure a balanced calcium-phosphorus ratio in the ration.

    A final word on providing beet pulp to horses—it comes as no surprise that horses are creatures of habit and will often eye a new addition to their feed tub as Poison Until Proven Otherwise. Many owners have tried adding beet pulp to their horse’s ration, only to have it stared at in horror, ignored or promptly dumped. Even if eventual plans are to feed the beet pulp dry, initially soaking a small amount of pulp until it becomes juicy and more palatable, and then mixing with grain or other already accepted feed, will help overcome reluctance on the horse’s part to trying something new. Eventually, most horses will deign to try the new feed and will soon be climbing over fences to get their fair share (or preferably, more than their fair share). At that point, amounts may be gradually increased and soaking may be tapered off until dry pulp is accepted equally well. Once the pulp is being regularly consumed, it may also be utilized as a useful method for "hiding" many other additions such as vitamin supplements, fats or medications.

Copyright Susan Garlinghouse, 1999.