Protein & Amino Acids in the Equine Diet
Posted by amy gill on Thursday, August 23, 2012 Under: Nutrition Tips & Advice
Proteins are sometimes called the building blocks of life, and when new tissues are made, large amounts of dietary protein are required. The stages in an animal’s life when new tissues are extensively manufactured are:
10 Essential Amino Acids – Their Functions
The ten essential amino acids that must be supplied by dietary means have a wide range of functions. A trick to remember the 10 essential amino acids is to recall PVT TIM HALL.
Phenylalanine
Effects of Amino Acid Deficiency
Lysine is the amino acid that is often in shortest supply in horse feeds and is particularly important for growing horses. Because feed ingredients used for horse rations can be deficient in some amino acids, most feed companies are now adding lysine, methionine, and threonine directly to the formulation of a supplement or concentrate in addition to the crude protein in the product. This is important because if one amino acid needed for protein synthesis is in short supply, that protein cannot be formed. This can lead to:
If necessary, the horse also can use protein as a source of energy during starvation or intense exercise by removing the amino group (the nitrogen portion of the molecule) and using the carbohydrate skeleton that is left for energy production. Starving horses or protein-deficient horses will catabolize muscle tissue to produce amino acids for other biological processes.
Take Home Message
When thinking about meeting your horse’s protein requirement, remember that it does not mean just supplying a certain amount of crude protein, but ensuring levels of specific amino acids as well. For situations in which protein requirements will be higher, such as growth, pregnancy, and lactation, be sure to re-evaluate your horse’s ration to make sure all requirements are being met.
- Growth
- Lactation
- Pregnancy
10 Essential Amino Acids – Their Functions
The ten essential amino acids that must be supplied by dietary means have a wide range of functions. A trick to remember the 10 essential amino acids is to recall PVT TIM HALL.
Phenylalanine
- Produces adrenalin & noradrenalin; is an anti-depressant
- Regulates protein turnover and energy metabolism along with isoleucine and leucine; vital for muscle coordination
- Produces serotonin and is a mood stabilizer; precursor to niacin and may aid in blood clotting
- Enhances growth and food efficiency; produces adrenalin and is a precursor to the thyroid hormone
- Helps form hemoglobin and fights nervous system degeneration
- Important for hair coat and growth; helps prevent deposits and adhesions of fat in the liver; essential for selenium bioavailability; second only in importance to lysine as a limiting amino acid
- Maintains plasma, hematocrit and serum albumin; releases histamine from the body; helps treat arthritis; stimulates stomach acid secretion and improves appetite
- Stimulates insulin and growth hormone release, helpful as nutritional aid in cancer therapy; stimulates immune system by boosting T-cell production
- Keeps muscle protein from degrading
- Enhances growth and nitrogen balance; promotes bone growth in foals; stimulates gastric juices
Effects of Amino Acid Deficiency
Lysine is the amino acid that is often in shortest supply in horse feeds and is particularly important for growing horses. Because feed ingredients used for horse rations can be deficient in some amino acids, most feed companies are now adding lysine, methionine, and threonine directly to the formulation of a supplement or concentrate in addition to the crude protein in the product. This is important because if one amino acid needed for protein synthesis is in short supply, that protein cannot be formed. This can lead to:
- Poor-quality growth and developmental disease in growing horses
- Poor body or muscle condition and possibly bone breakdown in working horses
If necessary, the horse also can use protein as a source of energy during starvation or intense exercise by removing the amino group (the nitrogen portion of the molecule) and using the carbohydrate skeleton that is left for energy production. Starving horses or protein-deficient horses will catabolize muscle tissue to produce amino acids for other biological processes.
Take Home Message
When thinking about meeting your horse’s protein requirement, remember that it does not mean just supplying a certain amount of crude protein, but ensuring levels of specific amino acids as well. For situations in which protein requirements will be higher, such as growth, pregnancy, and lactation, be sure to re-evaluate your horse’s ration to make sure all requirements are being met.