Horses depend on certain electrically charged minerals to maintain the balance and flow of vital body fluids, the transmission of nerve impulses and the healthy function of the muscles and the circulatory system. These minerals are called electrolytes. Their positive and negative charges help to control the body’ s pH( acid / base) balance and the transport of nutrients and waste products in and out of the cell. The minerals sodium, potassium, chloride, calcium, and magnesium collectively are termed electrolytes.
What do each electrolytes do?
Sodium and Chloride- NaCl, common salt, is the major electrolyte of the body. Salt is comprised of two electrolyte ions( charged particles) – sodium( Na +) and Chloride( Cl-). It is found in much higher concentration outside the cells( in the blood and other fluids surrounding the cells) than within the cell. The saltiness of the blood is measured as it is filtered through the kidneys. This way the body knows how much water to release in the urine to keep the concentration of salt in the blood at normal levels. When the horse becomes dehydrated and the blood sodium level is much more concentrated, sweating will slow or even stop as the body is trying to preserve the critical balance of salt to water.
Potassium- Inside the cells, potassium( K +) assumes the role as the major positively charged electrolyte. One of potassium’ s major roles is to keep the sensitivity of nerves and muscles at normal levels, not under or over reactive to impulses telling them to contract. This includes both skeletal and heart muscles.
Calcium- When we hear calcium, we think of bones and teeth. This is indeed a major function of calcium in the body, and most of the calcium is found within bones and teeth. However calcium in its ionic form( Ca ++) is an important electrolyte. Like potassium and magnesium, it is critical to the normal function of muscles and nerve tissue.
Magnesium- Magnesium is probably the most overlooked electrolyte. Although found in much smaller amounts than many other electrolytes. It has a critical role to play. Magnesium functions as a co factor for over 300 enzyme reactions within the body. This means if magnesium is not present or is present in an insufficient amount, each of these 300 reactions will suffer. Magnesium is required for normal muscle function, especially for relaxation of a muscle.
Phosphorous- Phosphorous is involved in the formation of bone. About 85 % of the body’ s phosphorous is located inside the bones in a solid form. The remainder is distributed between the blood and the interior of the cells. Inside cell, phosphorous is absolutely essential to the normal metabolism of carbohydrates, fats and proteins, as well as the generation and storage of energy from basic fuels.
Manganese- Manganese is an electrolyte you rarely hear about. Like magnesium, manganese is present in relatively small amounts compared to many other electrolytes, but it is essential to the formation of normal connective tissues( tissues that hold your body together), and the formation of joint cartilage.
Manganese plays a role in the metabolism of fat, the creation of DNA and the manufacture of cholesterol.
Copper- Copper is also present in very small amounts compared to the other electrolytes. The utilisation of iron to make red blood cells requires copper. Formation of the protective outer coating on nerves also requires copper, as does the production of skin pigments and the formation of healthy collagen – the major component of tendons and ligaments. Similarly, healthy joint cartilage can only be produced when there is adequate copper available.
Fluid Losses
Exercise generates a great deal of heat that must either be dissipated from the body or stored. The dissipation of heat is very important, because if a large amount of heat is stored, body temperature will rise to dangerous levels. In the horse, the processes that contribute to the dissipation of heat during exercise include radiation, convection, conduction and evaporation. Of these, evaporation may be the most important; particularly when horses are exercised in warm conditions. To facilitate evaporative cooling, horses sweat. Sweating is certainly desirable as a means to maintain body temperature, but high sweating rates result in high rates of water and electrolyte loss.
Horses consist of approximately 60 % water, which works out to be around 270 kg of water for a 450 kg horse. Most of the water is contained in cells( intracellular water) but some is outside of individual cells( extracellular water). Blood plasma, which constitutes a large portion
Page 36 • The Australian Quarter Horse Magazine • January • February • 2018