It depends. Horses on pasture may or may not need vitamin supplements. Good quality grass-legume pastures and iodized or trace-mineralized salt can supply adequate nutrients to maintain an adult horse at light work or mares during pregnancy. However, lush, early spring pasture may need to be supplemented with a high-energy source, such as grain, while late fall- and winter-pasture forage may require protein and vitamin A supplementation.
Why Might Horses on Pasture Need Vitamin Supplements?
The basic nutrients that animals require include carbohydrates, protein, fat, minerals, vitamins, and water. The energy needed for growth and activity is derived primarily from carbohydrates and fats. Protein will also supply energy, particularly if carbohydrate and fat intake is inadequate or if protein intake exceeds the needs of the body.
Vitamin A is required for growth, reproduction, milk production, and the maintenance of normal resistance to respiratory infections. All green-growing crops are rich in carotene, which animals can convert into vitamin A. Vitamin A supplement is often added to animal diets to ensure a supply when livestock are not fed green forages and are not on good pasture.
Vitamin D enables animals to use calcium and phosphorus; a deficiency causes rickets in young growing animals. The ultraviolet rays of sunlight produce vitamin D from the provitamin in the skin. Livestock that are outdoors in the sunlight much of the time have a plentiful supply of vitamin D. Under winter conditions in cold regions, cattle, sheep, and horses ordinarily get ample amounts from the hay they are fed.
The vitamin B group is not important in the feeding of cattle, sheep, and other ruminants, because the bacteria in their rumen synthesize these vitamins. Very young calves, however, and poultry, swine, and other monogastric animals require the B vitamins in their diets. Vitamin E is necessary for normal hatching of eggs. Vitamin C, which prevents scurvy in humans and guinea pigs, can be synthesized in the bodies of most other animals and need not be supplied in their food.
Vitamin K is synthesized by bacteria in the intestinal tract and can be absorbed, and, if livestock can ingest feces, a dietary supply is usually not important. Today many animals are raised without fecal contact, though, so vitamin K is often added to their diets as a safety factor.
What Factors Determine the Need for Supplements?
- Pasture Quality: Good quality grass-legume pastures can provide adequate nutrients for adult horses at light work or pregnant mares.
- Seasonal Changes: Lush spring pastures may require high-energy supplements, while late fall and winter pastures may need protein and vitamin A supplementation.
- Workload: Horses performing medium to heavy work may need additional supplementation.
- Life Stage: Growing or lactating horses have higher nutritional needs and may require supplements.
How Can You Ensure Horses Receive Adequate Vitamins?
- Assess Pasture Quality: Regularly evaluate the quality of the pasture to ensure it meets the horse’s nutritional needs.
- Provide a Balanced Diet: Supplement pasture with high-quality hay and grains as needed.
- Offer Mineral Supplements: Provide iodized or trace-mineralized salt to ensure adequate mineral intake.
- Consult with a Veterinarian: Work with a veterinarian or equine nutritionist to determine the specific vitamin and mineral needs of your horse.
What are the Risks of Over-Supplementation?
While ensuring adequate vitamin intake is crucial, over-supplementation can also pose risks. Excessive intake of certain vitamins and minerals can lead to health problems, such as toxicity or imbalances. Always follow recommended guidelines and consult with a veterinarian to determine the appropriate supplementation levels for your horse.
How Do You Know If a Horse Has a Vitamin Deficiency?
Signs of vitamin deficiency in horses can vary depending on the specific vitamin involved. Common symptoms may include:
- Poor growth
- Weakness
- Muscle stiffness
- Respiratory infections
- Reproductive problems
If you suspect your horse has a vitamin deficiency, consult with a veterinarian to conduct a thorough examination and recommend appropriate testing and treatment.
Horses were among the last species of livestock to be domesticated. Domestication took place at least as early as 3000 BCE, probably in the Near East. The wild ass, which when domesticated is usually called a donkey, was first domesticated in Egypt about 3400 BCE.
The specific and exact nutrient requirements of horses are poorly understood. Usually, these may be supplied economically from pasture forage, harvested roughages, and concentrates. Moldy or dusty feeds should be avoided because horses are extremely susceptible to forage poisoning and respiratory complications. Silages of all sorts should be avoided since horses and mules are extremely susceptible to botulism and digestive upsets.
Oats are the preferred grain for horses because of their bulk. Corn (maize), barley, wheat, and milo can be used, however, whenever they are less expensive. Weanling foals require three pounds of feed per hundred pounds of live weight per day; as they approach maturity, this requirement drops to one pound of feed per hundred pounds of live weight daily. Horses normally reach mature weight at less than four years of age and 80 percent of their mature weight at less than two years of age.
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