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The research behind Dapple Topline

Every ingredient, what it does for your horse in plain words, and the published research behind it from universities, vet journals and national science bodies. Horse studies are listed first.

Horse study = research done in horses Other research = lab or human research on the same ingredient

L-Lysine
1,250 mg per scoop

What it doesThe first amino acid a horse runs short of. Without enough lysine, the body cannot use the rest of the protein in the feed to build muscle.

Why it matters for an older horseOlder horses digest protein less well. Lysine is what most often stops them holding muscle along the back and hindquarters.

Amino acid supplementation improves muscle mass in aged and young horses Horse study

Graham-Thiers & Kronfeld · Virginia Tech · Journal of Animal Science, 2005

Older and younger horses given extra amino acids (lysine and threonine) scored higher for muscle, and lost fat without losing weight. That means more lean muscle.

Nutrient Requirements of Horses, 6th edition Horse study

National Research Council · The National Academies Press, 2007

The official reference used by vets and feed makers in the US. It names lysine as the first amino acid a horse runs short of, and sets daily lysine needs.

Modelling of amino acid turnover in the horse during training and racing Horse study

Dunstan et al. · University of Newcastle, Australia · PLOS ONE, 2020

A model of how much of each amino acid a hard-working horse uses up. Lysine, valine, glutamine and ornithine came out short, meaning normal feed may not cover them.

L-Arginine
1,250 mg per scoop

What it doesHelps the body make nitric oxide, which opens up blood vessels. Better blood flow carries food and oxygen to muscles and hooves.

Why it matters for an older horseBlood flow slows with age. Arginine supports the delivery system that feeds every other ingredient to the muscle.

Evaluation of dietary arginine supplementation in aged mares Horse study

Martinez et al. · Texas A&M University · Translational Animal Science, 2023

Older mares fed arginine every day had better blood flow to the womb before foaling. The daily dose used was found safe.

L-Ornithine
750 mg per scoop

What it doesWorks with arginine. Helps the body clear ammonia, the waste made when muscles work and use protein.

Why it matters for an older horseA cleaner system after work means less tiredness and a quicker return to normal.

L-ornithine and ammonia during and after exercise Other research

Demura et al. · Kanazawa University, Japan · European Journal of Clinical Nutrition, 2010

Ornithine helped the body handle ammonia, the waste made when muscles work and use protein, during and after exercise. Study in people.

Modelling of amino acid turnover in the horse during training and racing Horse study

Dunstan et al. · University of Newcastle, Australia · PLOS ONE, 2020

A model of how much of each amino acid a hard-working horse uses up. Lysine, valine, glutamine and ornithine came out short, meaning normal feed may not cover them.

Glycine
500 mg per scoop

What it doesOne third of collagen is glycine. Collagen is what hooves, skin, joints and tendons are built from.

Why it matters for an older horseResearch shows the body does not make enough glycine for collagen on its own. That shows up as weak hooves and stiff joints.

High glycine concentration increases collagen synthesis Other research

de Paz-Lugo, Lupiáñez & Meléndez-Hevia · University of Granada and Instituto del Metabolismo Celular, Spain · Amino Acids, 2018

Cartilage cells given more glycine made 60 to 75% more collagen. The authors found the body does not make enough glycine on its own for collagen. Lab study on cartilage cells.

L-Leucine
400 mg per scoop

What it doesThe switch that tells muscle to start building. Of all amino acids, leucine sends the strongest "grow" signal to muscle.

Why it matters for an older horseOlder muscle answers more slowly. Leucine helps turn the build signal back on.

Leucine stimulated protein synthesis in horse muscle Horse study

DeBoer et al. · University of Minnesota · Journal of Animal Science, 2018

Horse muscle cells given leucine built about 1.8 times more protein. Leucine switched on the pathway (mTOR) that tells muscle to grow.

Effects of branched-chain amino acids on immune status of young racing horses Horse study

Baakhtari et al. · University of Miyazaki and Japan Racing Association · Journal of Veterinary Medical Science, 2022

40 young Thoroughbreds in training. Mares fed leucine, isoleucine and valine had stronger immune cell counts than mares not fed them.

L-Isoleucine
400 mg per scoop

What it doesOne of the three branched-chain amino acids. Muscles burn it for energy during work.

Why it matters for an older horseHelps a senior horse keep going on a ride without breaking down its own muscle for fuel.

Effects of branched-chain amino acids on immune status of young racing horses Horse study

Baakhtari et al. · University of Miyazaki and Japan Racing Association · Journal of Veterinary Medical Science, 2022

40 young Thoroughbreds in training. Mares fed leucine, isoleucine and valine had stronger immune cell counts than mares not fed them.

Timing of feeding a protein supplement during exercise recovery in horses Horse study

Graham-Thiers & Bowen · Emory & Henry University · Journal of Animal Physiology and Animal Nutrition, 2024

Horses given amino acids after work kept more protein in the body, had a higher muscle marker and a lower muscle damage marker.

L-Valine
400 mg per scoop

What it doesThe third branched-chain amino acid. Supports muscle repair after work.

Why it matters for an older horseResearch on working horses shows valine is one of the amino acids they run short of.

Effects of branched-chain amino acids on immune status of young racing horses Horse study

Baakhtari et al. · University of Miyazaki and Japan Racing Association · Journal of Veterinary Medical Science, 2022

40 young Thoroughbreds in training. Mares fed leucine, isoleucine and valine had stronger immune cell counts than mares not fed them.

Modelling of amino acid turnover in the horse during training and racing Horse study

Dunstan et al. · University of Newcastle, Australia · PLOS ONE, 2020

A model of how much of each amino acid a hard-working horse uses up. Lysine, valine, glutamine and ornithine came out short, meaning normal feed may not cover them.

L-Glutamine
250 mg per scoop

What it doesThe most common amino acid in the body. It is the main fuel for the cells lining the gut, and for immune cells.

Why it matters for an older horseA healthy gut lining absorbs more of the feed. That matters for an older horse that already struggles to hold weight.

Impact of feed withdrawal on nutrient transport in the equine small and large intestine Horse study

Aldridge-Dean, Lescun & Radcliffe · Purdue University · Translational Animal Science, 2023

When horses went without feed, their gut took up 82% more glutamine. The gut lining uses glutamine as its own fuel.

Plasma glutamine concentrations in the horse following feeding and oral glutamine supplementation Horse study

Harris et al. · Equine Veterinary Journal, 2006

Measured how glutamine fed by mouth raises glutamine in a horse's blood, showing horses take it up from feed.

Modelling of amino acid turnover in the horse during training and racing Horse study

Dunstan et al. · University of Newcastle, Australia · PLOS ONE, 2020

A model of how much of each amino acid a hard-working horse uses up. Lysine, valine, glutamine and ornithine came out short, meaning normal feed may not cover them.

These studies are on the ingredients in Dapple Topline, not on Dapple Topline itself. They are independent and were not paid for by Dapple. Links open the original publication. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

Eight researched amino acids. One scoop a day.

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