Equine Nutrition - Starches And Carbohydrates

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No. Animals consume nutrients and other dietary components by weight, not percentage. The 3.3% represents that for every 100 lbs, 3.3 lbs would be starch. So let’s place that percentage in practical terms.

The fundamental questions of how much starch is actually how many grams of starch are in 4 lbs? One pound is the same as 454 grams. So 3.3% of 454 g is 14.98 grams, so let’s round-off to 15 g. Now that we know there are 15 g in 1 lb of this feed, since you are feeding 4 lbs then 15 X 4 = 60 g of starch in 4 lbs of feed.

What does 60 g of starch mean? For every 4 lbs of the feed, there are about 60 g of starch. Just keep in mind that unlike protein, fat, water or any vitamin or mineral there is no dietary requirement for starch, sugar or any non-structural carbohydrate.

Beet pulp is a byproduct from the processing of sugar beets. Herbicides or pesticides are not sprayed directly on beet pulp after the sugar beet processing. However, as with most agricultural plant crops, there are plant diseases, insects and weed issues that threaten sugar beet crops and therefore sprayed applications are not uncommon during the growth phase of the plant.

Regarding your second question, beet pulp is naturally dry and prickly. Some companies that sell it in sacks will add molasses to soften the product and of course there’s the benefit of flavor enhancing. In horse feeds, beet pulp is softened by the moisture from other ingredients as well as from the molasses and oils that may be added to the product. All horse feeds list the ingredients on the bag, so if molasses has been added it will be on there.

I suggest you read my fact sheet on Nonstructural Carbohydrates in Dr. Bray’s Corner. Our industry is in overdrive with concerns of starch/sugar and unfortunately many myths are circulating. Obviously I am not familiar with your horse’s particular situation, but if your horse has been clinically diagnose with IR then perhaps a comprehensive review of your horse’s diet may be appropriate to ensure their nutrient requirements are met while minimizing the nonstructural carbohydrate intake.

Integrity Lite No Molasses is the lowest starch balanced formula of the Integrity products and is a low sugar formula. You can add calories for weight gain by top dressing the Integrity Lite with Integrity Rice Bran or oil. Rice bran has more starch than oil, which is 99.9% fat.

You may want to consider feeding a different hay that is lower in starch, such as timothy or Bermuda. My forage feeding recommendations include that not more than 50% of the forage fed can be alfalfa and not more than 50% of the hay can be processed hay (pellets or cubes).

NSC is nonstructural carbohydrates and there is much confusion in the horse industry on how to evaluate carbohydrate content in feeds. Percent NSC is often the request I receive but is not a value that I use for evaluation. % NSC was originally a calculated value that did not really reflect valuable information on carbohydrate content Now the value is used loosely, a catch-all expression. Depending on the source, it may represent just starch, or starch and WSC (water soluble carbohydrates), or WSC and ESC (ethanol soluble carbohydrates), or only fructans. This confusion not only exists with horse owners but also in the veterinarian community.

Below is a table of hay pellets sold by Star Milling that provides data on starch, sugar, and other nonstructural carbohydrate content. The laboratory analyses that provide useful information are % starch, % ethanol soluble carbohydrates (ESC) and % water soluble carbohydrates (WSC). These three analyses provide different information. Depending on the concern, such as insulin resistant, laminitis, PSSM, colic, etc., the analysis that is used is dictated by the issue/illness being addressed.

A simple overview of what each analysis provides:

  • % Starch • Starches, some are resistant to small intestine digestion
  • % ESC - ethanol soluble carbohydrates • Represents carbohydrates digested in the small intestine. They are the carbohydrates that produce a true glycemic (blood sugar) response
  • % WSC - water soluble carbohydrates • Includes simple sugars, oligosaccharides (several sugar molecules hooked together) and fructans

Hay Pellet Sugar, Starch, Nonstructural Carbohydrate Data*

Hay Pellet % WSC % ESC % Starch % Starch+ % ESC
Hay & Grain 3/8 pellet 5.7 4.2 5.3 9.5
Alfalfa Bermuda 3/8 pellet 6.4 5.4 1.2 6.6
Oat hay ¼ pellet 6.3 5.3 0.7 6.0
Bermuda ¼pellet 7.7 6.0 3.3 9.3
Alfalfa ¼ pellet 7.8 8.1 6.4 14.5
Timothy ¼ pellet 14.5 9.3 1.3 10.6
Alfalfa 3/8 pellet 6.0 5.2 5.1 10.3
Alfalfa Oat 3/8 pellet 6.2 7.2 2.7 9.9
Alfalfa Timothy (50/50) ¼ pellet 7.6 6.0 1.4 7.4

*Values reported on as sampled or as fed basis.

  • WSC is water soluble carbohydrates
  • ESC is ethanol soluble carbohydrates
  • NSC is nonstructural carbohydrates and NSC = Starch + WSC
  • Fructan content of feeds will vary but a crude estimate can be calculated by subtracting ESC from WSC

Fructan is a carbohydrate made-up of the simple sugar fructose that is more concentrated in cool season grasses than warm season grasses and has been associated with precipitating laminitis and/or colic. For forages, fructan is a carbohydrate that is important to consider but the amount in the grass will vary with growth stage of the plant. Percent water soluble carbohydrates (WSC) represents sugars, some starch, and fructan content but the problem with using only % water soluble carbohydrates to assess fructan concentration is that one does not know the actual percentage of fructan in the %WSC analysis. Therefore one should use % starch along with %WSC for forage assessment.

There is confusion in the horse industry on how to evaluate carbohydrate content in feeds. Percent NSC is often the request I receive but is not a value that I and other nutritionists use for evaluation. % NSC was originally a calculated value that did not really reflect valuable information on carbohydrate content and now the value has been a catch-all expression that depending on the source may represent just starch, or starch and WSC (water soluble carbohydrates), or WSC and ESC (ethanol soluble carbohydrates), or only fructans. This confusion not only exists with horse owners but also in the veterinarian community.

The laboratory analyses that provide useful information are % starch, % ethanol soluble carbohydrates (ESC) and % water soluble carbohydrates (WSC). These three analyses provide different information. Thus depending on the concern, such as insulin resistant, laminitis, PSSM, colic, etc., the analysis that is used is dictated by the issue being addressed.

Here is a simple overview of what each analysis provides:

  • % Starch - starches, some are resistant to small intestine digestion
  • % ESC (ethanol soluble carbohydrates) - represents carbohydrates digested in the small intestine thus are the carbohydrates that produce a true glycemic (blood sugar) response
  • % WSC (water soluble carbohydrates) - simple sugars, oligosaccharides (several sugar molecules hooked together) and fructans

Since your pony is 33 years old and most likely a companion and not active, I would suggest the Integrity Lite without molasses which has 1.6 % starch.

There is much confusion in the horse industry about carbohydrates which is understandable because carbohydrates are a complicated class of chemicals. There are different laboratory assessments used to measure the different classes of carbohydrate chemicals. A standard to provide an understanding of starch content in horse feeds is the numerical value that represents % starch and the ethanol soluble carbohydrates (ESC). The ESC for Integrity Lite without molasses for is 5.9% thus the %Starch + %ESC for Integrity Lite without molasses is 7.5%.

Integrity Lite without molasses of course does not have molasses, does not contain any grains and the first two ingredients are beet pulp and soybean hulls which are “fiber” sources that promote gut integrity. You indicated your pony has worn-down molars and has issues with chewing so adding water to soften the feed is a practice some horse owners will use. Start with equal volume of water and the goal is to soften the feed. If your pony is an aggressive eater and tends to eat fast and not take time to chew, you can place “small rock boulders” in the feed bucket to create obstacles so that he has to navigate around the heavy objects to eat. This nutritional management practice will slow down the rate of feed consumption. Obviously, the “small rock boulders” phrase is a bit-of-humor because the rock-obstacles must be large and heavy enough so that the pony or horse is unable to pick any up by the mouth.

The Integrity Lite contains not more than 20% crude fiber but I always recommend a fiber source such as baled-hay or pasture. If baled-hay (long-stem fiber source) is not an option then you can feed a hay pellet. Fiber is a critical part of the horse’s diet so adding the hay pellet with the Integrity Lite is a better option than a ‘complete’ feed. You will have flexibility in regulating his diet.

Follow-up Note: Further details about the pony (see What to Feed your Horse) provided the information needed to recommend a blend of 1 lb. Integrity Lite without molasses with 6.5 lbs. of a hay pellet to start; adjustments would be made based on body condition score changes.

The percentage of starch and ESC (Ethanol Soluble Carbohydrates) are the measurements I use to evaluate the non-structural carbohydrates in a feed. NSC is mathematically calculated from the following: %NSC = 100 – (moisture + NDF + CP + Fat + Ash) and thus is an indirect empirical (mathematical) determination. The empirical score that one sees as % NSC has variables and inconsistencies when comparing feedstuffs. The Integrity Adult/Senior (No Molasses) contains 5.5% starch and 5.9% ESC. Integrity Lite – No Molasses contains 1.6% starch and 5.9% ESC. Integrity Timothy contains 13.2% starch and 7.4% ESC.

The lowest starch and highest fiber formula in the Integrity product line is Integrity Lite without molasses. This formula is well suited for older horses that may be inactive or worked lightly. As with all Integrity formulas, Integrity Lite is a balanced formula to complement the forage portion of the horse’s diet. Integrity Timothy is a formula more suited for more active working horses and does not contain the high starch grains corn and barley.

IThe NSC is not a value that I use for evaluation. The laboratory analyses that I use to evaluate feeds are % starch, % ethanol soluble carbohydrates (ESC) and % water soluble carbohydrates (WSC). These three analyses provide different information.

The forage pellet company that makes the teff pellet does not have information on % starch and % WSC. However, published data on teff hay reports % starch as less than 1.0%, % ethanol soluble carbohydrates approximately 4.3%, and % water soluble carbohydrates approximately 6.1%. Teff hay is a warm season grass and generally will have lower carbohydrate analyses than cool season grasses.

I actually like teff hay but the west coast horse owners are not using it. The lower demand means less will be grown and perhaps teff hay will not be available in some regions in the near future. I hope not because horse owners are missing out on a good alternative to other west coast grass forages.

The high-moisture feed you reference is not a feedstuff I recommend because of concerns with adequate fiber intake. Forages are the essential food source for horses (in fact, for all non-ruminant herbivores). Forages provide a source of energy and nutrients but more importantly, provide a source of fiber. Fiber is not a nutrient but is an essential component of a horse’s diet because of its role in promoting a healthy gut. Hay is approximately 90% dry matter (10% water) compared to the high moisture feed which is 55% dry matter (45% water). When comparing feeds, the comparison MUST be with equivalent dry matter or moisture content. The feeding recommendations of the high moisture forage provide inadequate fiber to the horse’s diet. In addition, the feedstuff relative to the cost per unit weight of dry matter is much more expensive than grass forage in the form of hay. Anytime a feed is processed, the cost of the feed is higher.

There is much confusion in the industry relative to non-structural carbohydrates (includes starch and sugars) being fed to horses. That confusion is perpetuated by internet blogs, some feed reps, and even professionals whose intentions are perhaps good, but usually limited relative to their knowledge with nutrition and nutritional management of horses. In the May 30, 2011 Feedstuffs, Dr. Pagan of KER wrote an excellent article on non-structural carbohydrates that address the misleading information circulating in the industry.

Our approach at Star Milling is to address the specific questions of customers, which is one reason why Star Milling setup Dr. Bray’s Corner so that the company can directly help our customers with questions. The Integrity Lite, No Molasses formula is the feed that best serves your needs and I have provided a table with the % starch and % starch + % ESC information regarding both Integrity Lite products. However please note that the emphasis is on total starch consumed not just the starch that is in the concentrate. The amount of concentrate being fed relative to the type and amount of forage being fed are key considerations when reviewing a horse’s diet that has been diagnosed with IR. Please note that Integrity Lite with no molasses is significantly lower than the formulas you are currently feeding.

Horse Feed and Form % Starch % Starch + % ESC
Integrity Lite, textured 3.3 10.6
Integrity Lite, No Molasses, textured 1.6 7.5
Your current Lite Pelleted  being fed 4.5 9.5
Your current Senior Textured being fed 6.4 13.2

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