Technical Research

Equinutrix researchers have spent countless hours in the laboratory to build a product line that works. Included in this section of our site is more in-depth information on:

  • How stressful is everyday stress?
  • What’s the big deal with starch?
  • Exercise Recovery

How stressful is everyday stress?

As a horse senses something potentially dangerous, or simply a stressful situation, the senses (hearing, sight and smell) deliver that stressful message to the brain which leads to a reaction by the horse. This message is passed between neurons until it reaches the brain. The stress message heads to areas of the brain that control emotions, mood, and pleasure, which are located within the hypothalamus. These control centers process the stress message and determine how the horse reacts. In some cases the reaction may be as minimal as a lack of attention shown to the rider; others could be as dramatic as fleeing the situation and running away.

Short term effects of stress:

  • Grinding teeth
  • Agitation
  • Anxiety
  • Nervous/flighty behavior
  • Stereotypies (i.e. – weaving, pacing, cribbing, or general stall destruction)
  • Reduced focus on competition

Long-term effects of stress:

  • Increased systemic inflammation
  • Increased susceptibility to disease
  • Increased susceptibility to ulcers
  • Metabolic disturbances
  • Reduced performance
  • Decreased fertility
  • Less milk production

If you are concerned with your horse’s stress level, check out the product research on ZENRG and Maximum ZENRG, contact us or your veterinarian!

What’s the big deal with starch?

normal hoof radiograph   laminitis hoof radiograph

Horses evolved as grazers consuming poorly digestible, grass-based diets that were low in nonstructural carbohydrates (NSC; sugar + starch). However, modern commercial diets contain higher levels of NSC which has been shown to predispose horses to impaired glucose and lipid metabolism. These impaired metabolic conditions are linked to a deadly disease of the hoof, laminitis.  Until recently, the link between alterations in metabolism, low-grade chronic inflammation associated with obesity, NSC in the diet, and laminitis has remained a black box. Research has now demonstrated that even in metabolically normal horses, NSC ingestion causes the microflora in the gut to produce lactate (a strong acid) and toxins while creating a leaky gut.  This allows for lactate and toxins to be absorbed into the blood stream, which leads to a rise in inflammation. 

For horses that are obese, or metabolically predisposed to insulin resistance, there is already a high level of circulating inflammation, which further impairs insulin signaling.  Horses have a threshold for this inflammation and consuming higher levels of NSC in the pasture, such as during the Spring and Fall, or in the grain, by over-consumption, can push the systemic inflammation over this threshold, which leads to a laminitic episode.

If you are worried about the NSC level in your horse’s diet, contact us or your veterinarian to have your feed tested, and check out the product research on Starch Guard. Because your horse’s health is our top priority, if you think your horse may be insulin resistant or laminitic, contact your veterinarian as we are happy to work with them on your horse’s dietary needs.

Exercise Recovery

But isn’t exercising healthy?  When it comes to our own health, that is what we hear.  Exercise, eat right.  Well, yes, but if you were out of shape, you wouldn’t go run a marathon, would you?  No.  Because stamina and training are required for an intense type of workout.  The same is true for your horse.  You may be thinking, but my horse isn’t out of shape he is worked 3-5 times a week.  That is great! But is at as intense as when you show or compete?

The majority of injuries in elite equine athletes are musculoskeletal and attributed to injuries during training and competition (Jeffcott et al., 1982; Bailey et al., 1997; Wilsher et al., 2006).  As a matter of fact, tying-up, limb soreness and lameness are the number one reasons to retire racehorses, and that the majority of these injuries occur during training rather than competition (Wilsher et al., 2006; Egenvall et al., 2013)!  Most horses aren’t in the elite athlete category, but are weekend warriors, whose owners have to work or go to school during the week, focusing on their equestrian activities on the weekend.  Assuming life doesn’t get in the way of your training during the week, and your horse is getting worked 3 times a week, was the intensity as high as when you compete?  A recent trial presented at the Equine Science Society meeting (Pagan et al., 2017a; Pagan et al., 2017b), showed that even 3 and 4* eventers are not training to the same level as they are competing.  Additionally, after intense exercise, like that experienced during competition, a five day rest period isn’t sufficient for the muscle metabolites to return to normal (Assenza et al., 2016).  So, are we setting our horses up for injuries and soreness?

A cascade of events occur following a single bout of exercise:

  • Build of lactic acid
  • Decrease in blood pH
  • Increase in inflammation
  • Increase in protein synthesis*
  • Depletion of glycogen

*Protein degradation could also occur if the exercise was too strenuous.  This would outweigh the benefits of protein synthesis and lead to muscle breakdown. A future technical research section will address protein synthesis and degradation and how to build muscle.

Although the direct cause of muscle soreness following exercise has not been fully elucidated, and was once thought to be a result of lactic acid build up, may be a result of a combination of the physiological events that occur post-exercise.  Either way, muscle soreness is a problem and can lead to injuries during training and competition. 

What is glycogen? And why do we care if exercise depletes it?

Glycogen is the storage form of energy in muscle cells.  When horses exercise, their muscles contract and it takes energy to facilitate this contraction.  At the molecular level, this energy is called ATP, but it needs a source.  Glucose that is consumed in the diet is stored in the muscle as glycogen.  When a horse is exercising glycogen is broken down and used to make ATP that can be used to allow the muscle to contract.  When glycogen stores are depleted, the stored energy source must be reestablished.  This puts your horse at a disadvantage when competing over consecutive days.  Horses do not replenish glycogen stores in the muscle as readily as humans do.  So, if your muscles feel tired and aren’t cooperating as well as they should when you are riding on day two or three of a show or event, imagine how your horse feels; as your trainer is shouting “More leg!”

Severe exercise induced muscle soreness

Tying-up or “Monday Morning Sickness” as it is commonly referred to is a result of abnormal physiology in the muscle of the animal that leads painful uncontrollable muscle spasms. Although most horses that are prone to episodes of tying-up are due to genetic issues and other physiological problems that have yet to be elucidated, a trigger for the episode is typically a stressful event, over-exertion of an unfit horse, or an unbalanced diet. For more information on Tying-up, check out this great review.

If you have concerns with muscle soreness in your horse check out the product research on Muscle Refresh, contact us or your veterinarian.


  1. Assenza, A., S. Marafioti, F. Congiu, C. Giannetto, F. Fazio, D. Bruschetta, and G. Piccione. 2016. Serum muscle-derived enzymes response during show jumping competition in horse. Vet. World. 9(3):251-255.
  2. Bailey, C.J., S.W. Reid, D.R. Hodgson, C.J. Suann, and R.J. Rose. 1997. Risk factors associated with musculoskeletal injuries in Australian thoroughbred racehorses. Prev. Vet. Med. 32(1-2):47-55.
  3. Jeffcott, L.B., P.D. Rossdale, J. Freestone, C.J. Frank, and P.F. Towers-Clark. 1982. An assessment of wastage in thoroughbred racing from conception to 4 years of age. Equine Vet. J. 14(2):185-198.
  4. Egenvall, A., C.A. Tranquille, A.C. Lonnell, C. Bitschnau, A. Oomen, E. Hernlund, S. Montavon, M.A. Franko, R.C. Murray, M.A. Weishaupt, V.R. Weeren, and L. Roepstorff. 2013. Days-lost to training and competition in relation to workload in 263 elite show-jumping horses in four European countries. Prev. Vet. Med. 112(3-4):387-400.
  5. Pagan, J.D., K. O’Neill, N. Ireland, and M. Davies. 2017a. Intensity of exercise during early-season competition in three-day-event horses assessed using KER ClockIt Sport smartphone application. J. Equine Vet. Sci.52:67.
  6. Pagan, J.D., E. Mulvey, K. O’Neill, N. Ireland, and M. Davies. 2017. Intensity and distance of exercise during training in advanced three-day event horses and thoroughbred racehorses assessed using KER ClockIt smartphone application. J. Equine Vet. Sci. 52:67-68
  7. Wilsher, S., W.R. Allen, and J.L. Wood. 2006. Factors associated with failure of thoroughbred horses to train and race. Equine Vet. J. 38(2):113-118.