The effects of feeding excess dietary protein

 

Why does my horse need protein?

Some of the key functions of proteins in your horse’s body include providing structure, nutrient transport in the blood stream, nutrient transport across cell membranes, regulation of metabolic function, as a component of the immune system and to act as a buffer to minimize fluctuations in body pH. Protein assists in tissue repair and growth,muscle function and heart health the  amount of protein required in growing, pregnant, lactating or heavy exercising horses is increased.

Protein Digestion overview:

Proteins are composed of units called amino acids. Although there are 21 different amino acids that are needed for protein synthesis, several can be made by the tissues of the body. Amino acids that must be provided in the diet are referred to as indispensable (essential) amino acids, and amino acids that the animal can make through its own metabolic pathways are termed dispensable (non-essential) amino acids. In order for your horse to be able to utilize dietary protein throughout his body they must first be digested into these individual amino acids.  The digestion of protein begins in the stomach, through to the small intestine which results in the end product the free amino acids. These are then available for absorption into the blood stream and used for various functions throughout your horse’s body. The absorption rates of individual amino acids are highly dependent on the protein source.

 

The latest research on protein in horses indicates that excess dietary protein, especially processed, can have several damaging effects. These include:

(1) High blood urea nitrogen and ammonia levels:

Urea is made when protein is broken down in your body. Urea is made in the liver  and passed out of your body in the urine.

Nitrogen is a component of both ammonia and urea. Urea and urea nitrogen are referred to somewhat interchangeably because urea contains nitrogen and because urea/urea nitrogen is the “transport method” used by the body to rid itself of excess nitrogen. Urea is released by the liver into the blood and is carried to the kidneys, where it is filtered out of the blood and released into the urine. Since this is an ongoing process, there is usually a small but stable amount of urea nitrogen in the blood.

Overview:

•  The liver produces ammonia which contains nitrogen -after it breaks down proteins used by your body’s cells
• The nitrogen combines with other elements, such as carbon, hydrogen and oxygen, to form urea, which is a chemical waste product.
• The urea travels from your liver to your kidneys through your bloodstream.
• Healthy kidneys filter urea and remove other waste products from your blood.
• The filtered waste products leave your body through urine.

Nitrogen is a component of both ammonia and urea. Urea and urea nitrogen are referred to somewhat interchangeably because urea contains nitrogen and because urea/urea nitrogen is the “transport method” used by the body to rid itself of excess nitrogen. Urea is released by the liver into the blood and is carried to the kidneys, where it is filtered out of the blood and released into the urine. Since this is an ongoing process, there is usually a small but stable amount of urea nitrogen in the blood.

Protein that is over what is required must be excreted via the urine and the manure. For this to be done it must first be converted to urea and ammonia by the Liver. High blood urea and ammonia levels on a blood test can indicate that the horse is getting too much protein in the diet. However, if horses are getting insufficient dietary energy and are breaking down body tissues for energy, this will also elevate blood urea and ammonia levels.

(2) Liver and Kidney stress: Recent research suggests that over feeding of protein per day exceeds the ability of the liver to convert protein to urea and ammonia for excretion in the urine. This places and added burden on the liver and the kidneys, and high gut urea levels can increase intestinal disturbances, and can be one of the causes of both ‘hanging’ or ‘bursting’ and also loss or decrease in appetite.

(3) Increased fluid and electrolyte demands: To excrete the extra ammonia and urea requires electrolytes and water. This places an added demand on body water and electrolyte reserves and increases urinary output. If, however the horse has a kidney weakness and is unable to handle the excess urea or ammonia there will be a build up of lactic acid with the resulting loss of performance or even ‘tying-up’, ‘Azotoria’ and ‘bursting’ or simply fading at the end of a race.

(4) Nervous /hyperactive: High urea and ammonia in the blood affect the nervous system, causing irritable behaviour and restlessness, and can disturb energy production during exercise. Horses on high grain will increase horses irritability and become agitated best to cut down on grains and offer alternatives such as cool grain mixes.Protein is sometimes blamed for making horses ‘hot’ and some horse owners will actively select low protein feeds in an effort to keep their horses calm.

(5) Increased risk of respiratory conditions: High ammonia in the urine contaminates the stable environment. This is especially noticeable in warm weather, the ammonia fumes affect humans and horses alike, irritating the eyes and respiratory system and predisposing to respiratory infections and viruses.

6) Poor performance: Studies in America have demonstrated that feeding excess nitrogen over recommended levels can prolong racing times by up to 3 seconds.A high volume of lactic acid in the bloodstream can lead to many performance and health problems. Hindgut acidosis can lead to laminitis, hindgut inflammation, ulceration and even colic. It can also reduce the ability of the horse’s muscles to remove exercise induced lactic acid, leading to a slower recovery from exercise or even tying up.

(7) Excess protein can cause calcium deficiency: Feeding excess protein has been found to leach calcium from the body due to increase in Uric Acid causing poor bone density, weak lung walls, weak bowel walls and can lead to internal bleeding i.e. ‘bursting’ and bone fractures.

(8) Excessive urinating :
Horses on high protein diets will. Getting rid of waste nitrogen requires a lot of water so horses on high protein diets tend to drink AND urinate a lot. Now, this isn’t a problem if your horse has ready access to water and lives outside. But for horses in stables, feeding too much protein is going to mean a whole lot of extra wet bedding for you to muck out every day, which is time consuming and can be expensive depending on what you pay for bedding.

Vitamins and minerals which are all available in herbal form are 100% safe and absorbable simply because having already been digested once by the plant they are easier to absorb by the horse and any excess that are not needed will be easily flushed out by the kidneys or through the bowels.

It has been found after research into horses that ‘burst’ that a much higher percentage, 78% responded to treatment when fed on a majority oat ration must be  whereas with horses fed on processed concentrates, the response to treatment was much lower approx only 25%.

Oats are classed as both a herb (avena sativa )and a food, they are a strength-giving cereal, low in starch but high in minerals. Also rich in Vit. B they contain alkaloids, glycosides and fixed oils which are an important source of Vit. E. They are a nerve tonic and bone building and contrary to modern day thinking are the best possible feed for horses that are in work. The best way to feed them is soaked as explained here.

The herb and the food benefits of oats

This wonderful herb is thought to be soothing to the brain and nervous system,

Avena sativa seeds are not only a rich source of carbohydrate and soluble fibre, they also have the highest content of Iron, Zinc and Manganese of any grain. It is said to be useful as a nerve restorative.

As a food, oats are known to be good for the heart because they keep blood fats under control.

Soaked whole oats, soaked for approx. 12 hours in cold water, this makes the oats a living enzyme again, which enables the horse to digest them more easily. Because they are now a living enzyme and easier digested the energy is released into the system quicker and without any build up of lactic acid, so no tying up, and also they do not affect the temperament due to no starch build up in the hind gut. The other benefits of soaking include the fact that any chemical residue from sprays etc., are washed away, but not the goodness of the oat, also as Vit E is in the outer husk of the oat, after soaking it becomes easier to assimilate. The oats should be drained if possible overnight or for at least an hour before feeding, and enough can be put up to last a whole day.

Reference:

The natural healthy horse /protein and performance .

hygain.com.au/protein/