Protein is part of the main staple of a PSSM2 horses diet, but what exactly is protein why does it significantly help in terms of PSSM2 management?

What Is PSSM2?

PSSM2 is an umbrella term used for a group of muscle diseases. The easiest way to think of PSSM2 is like a filing cabinet, where everything that looked a bit like PSSM1 but wasn’t got chucked into.

In the PSSM2 filing cabinet there are currently 2 muscle diseases & these are MFM (Myofibrillar Myopathy), and RER (Recurrent exertional rhabdomyolysis) MFM & RER are both hereditary muscle diseases.

What Is PSSM2?

What Are Proteins?

Proteins are the most abundant molecules in the body, they are made up of large chains (Polymers) of Amino Acids which are linked together by peptide bonds (a chemical bond linking 2 consecutive amino acids together).

When Were Proteins Discovered?

Proteins were discovered in 1838 by Dutch analytical chemist Gerardus Johannes Mulder, it was later named by the Swedish chemist Jöns Jakob Berzelius, the word protein is derived from the Greek word prōteios which means “holding in place.”

When was protein discovered?
Jöns Jakob Berzelius & Gerardus Johannes Mulder

What Is The Function Of Proteins?

Proteins are the building blocks of body tissue and is the major structural component within the body; it can be found in cells, muscle, membranes, body organs, hair, and skin. When broken down into amino acids, proteins are also used for hormones, nucleic acid (the main information-carrying molecules of the cell), cellular repair, immune response, and as precursors to co-enzymes (a substance that enhances the action of an enzyme). Protein is also used to form blood cells and as a source of fuel.

How Do Proteins Aid In Muscle Function?

Without protein animals and humans physically couldn’t survive because 80% of what makes up muscles is protein- now that’s a big number!

Muscles are made up of 1000’s of tiny elastic fibers which are bundled tightly together. Each one of these bundles is wrapped in a thin transparent membrane called a perimysium. Individual muscle fibers are made up of blocks of proteins called myofibrils, myofibrils contain molecules and specialised proteins called myoglobin that help provide the oxygen and energy required for muscle contraction.

How Does Protein Aid In Muscle Function
Here we can see how many myofibrils are in 1 single muscle fibre, and muscles are made up of 1000’s of these!  
©2009 Pearson Education

Can Horses Produce Protein?

No horses cannot produce protein, it is something they can only get from food sources.

Where Is Protein Found In A Horses Diet Naturally?

Protein is found in good quality pasture, and forage, and for a normal horse without PSSM2 they will get enough protein in their diet from these sources alone.

Why Do PSSM2 Horses Need Supplemented Protein?

Dr Stephanie Valberg was the person to discover that PSSM2 horses benefit from protein, but it was a matter of chance and a bit of a guess that she stumbled upon this discovery. Dr Valberg observed PSSM2 horses with muscle wasting and the way that they would rapidly lose muscle when they entered negative nitrogen balance, so her suggestion was to add protein to see if it helped, and to her surprise it did.

(Top photo) Nellie an N/P3 N/PX Thoroughbred mare, before the PSSM2 diet suffering severe muscle wasting as a result of negative nitrogen balance.
(Bottom photo) Nellie after a few months of supplemented protein added into her diet we can see she is now back to normal body condition.
Nellie is one of the 100’s of PSSM2 horses who with the addition of protein into her diet, has seen improvement

But why did adding protein into the diet make such a difference to these PSSM2 horses? To find this out we now have to delve into the science.

One of the consistent results scientists are seeing on muscle biopsies of PSSM2 affected horses is an elevated frequency of centrally located nuclei. Nuclei also know as Nucleus is a membrane-bound organelle (a subcellular structure that has one or more specific jobs to perform in the cell) that contains the cell’s chromosomes.

But why were scientists seeing so much centrally located nuclei in PSSM2 horses? To answer this we must delve even further. Muscle is constantly regenerating from stem cells. The formation of a muscle fiber is a complex process that starts with the fusion of cells called myoblast (embryonic precursors of muscle cells). As the muscle fiber differentiates, one of the last things to happen is that nuclei (of which a muscle fiber has multiple) migrate from the center of the fiber to the edge. The fact that scientists were seeing so many centrally-located nuclei under the microscope in PSSM2 horses means that there are a lot of muscle fibers constantly regenerating.

Muscle fibers that are full of aggregates and disorganized myofibrils caused by PSSM2 are torn down, and new fibers will take their place, because PSSM2 causes a mutation in muscle proteins this process is one that is happening on repeat, this increased turnover of muscle tissue increases the horses need for protein.

What Happens When A PSSM2 Horse Doesn’t Get Enough Protein?

When a PSSM2 horse doesn’t get enough protein PSSM symptoms start to occur, including:

In severe cases a horse can enter negative nitrogen balance.

What Forms Of Protein Supplementation Are There?

Protein can be supplemented in the form of hardfeed, and powdered protein sources including:

-Chia Seeds
-Copra
-Hemp Protein
-Hemp Seeds
-Linseed (Flax seed)
-Pea Protein
-Pumpkin seeds
-Soybeans
-Spirulina
-Split Peas
-Sunflower Seeds
-Tri Aminos
-Vicia Fabia (Tick bean)
-Whey Protein

How Do I Know Which Form Of Protein Is Best For My PSSM2 Horse?

When it comes to choosing a protein for your horse its important to research into the protein beforehand, some protein sources are high in sugar compared to others which would not be good for a horse with both PSSM1 & PSSM2. The most common protein sources used by PSSM2 owners are pea protein, whey protein, hemp protein linseed, copra, and/ or Tri Aminos.

Where Can I Purchase Protein From?

You can purchase protein from any health or sports store.