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Animal nutrition · the basics

Vitamins & Minerals

Small amounts can have large consequences. Balance, form, species, and the complete feeding program all matter.

For poultry, horses, cattle, sheep, and goats. Other species need separate guidance; examples are labeled by species.

Updated 3 min read

In this guide
  1. Vitamins help metabolism work
  2. Major and trace describe amount, not importance
  3. Total content is different from availability
  4. The right amount depends on the animal
  5. Make a supplement inventory
  6. Sources

Vitamins help metabolism work

Vitamins support specific metabolic functions without supplying dietary calories. Classification helps describe their behavior, but it does not tell you that every animal needs the same supplement. [1]

Fat-solubleA, D, E, and K

Water-solubleB vitamins and C

Vitamin groups [1]

Some fat-soluble vitamins, especially A and D, can accumulate and be toxic in excess. Water-soluble is not permission for unrestricted dosing. Use a species-appropriate feeding plan rather than assuming that more vitamins mean better nutrition. [1]

Major and trace describe amount, not importance

In horse nutrition, major minerals include calcium, phosphorus, magnesium, sodium, chloride, potassium, and sulfur. Trace minerals include copper, zinc, iodine, and selenium. Both groups matter. Selenium has a narrow margin between useful and toxic intake; check all supplements and fortified feeds together. [2]

The animal needs a balanced mineral supply, not simply a high total. For sheep and goats, mineral requirements and tolerances differ, and interactions among copper, sulfur, and molybdenum influence assessment. A mineral source cannot be evaluated independently of the whole diet. [7]

Total content is different from availability

In poultry, much of the phosphorus in seeds can be bound in phytate. Birds cannot use all of it without suitable digestive help. Formulated phytase can improve access, but total phosphorus alone does not establish available phosphorus or a balanced calcium–phosphorus supply. [3]

The right amount depends on the animal

Growing chickens and laying hens have different calcium needs. High-calcium layer feed is inappropriate for growing birds and can cause kidney damage. Choose feed for the birds’ stage rather than adding calcium to every flock. [4]

Sheep are particularly sensitive to excess copper. Use mineral supplements formulated for sheep, and keep sheep away from unsuitable goat or cattle products. For mixed groups, read the product’s species directions and cautions; do not assume shared pasture means a shared mineral program. [5]

For horses, extra vitamins A and D can be harmful. Follow vitamin-premix directions and account for amounts already supplied by other feeds before top-dressing. Several individually reasonable products can create an excessive combined supply. [6]

Make a supplement inventory

List every fortified feed, mineral, balancer, supplement, and treat. Record the label directions and what is actually fed. Ask which need each product addresses and what evidence supports its form and availability. Terms such as “organic” or “chelated” are a starting question, not a guarantee of the best choice for your animal.

For illness, poor body condition, or unexplained changes in performance, involve your veterinarian. Plan pregnancy and lactation diets with qualified help. For feed selection questions, ask our nutritionist.

Sources

Original Tucker Milling guide, informed by these primary sources. The cited institutions do not endorse Tucker Milling. Follow the current product label.

  1. Vitamins ↩

    Oregon State University · Principles of Animal Nutrition · chapter 13

    Accessed October 8, 2026.

  2. Providing your horse vitamins and minerals ↩

    University of Minnesota Extension

    Mineral balance and selenium; not its excess-vitamin advice. Accessed October 8, 2026.

  3. Phytate ↩

    Jacquie Jacob · University of Kentucky · Poultry Extension

    Accessed October 8, 2026.

  4. Feeding Chickens for Egg Production in Small and Backyard Flocks ↩

    Jacquie Jacob · University of Kentucky · Poultry Extension

    Accessed October 8, 2026.

  5. Nutrition and feeding for sheep and goats ↩

    Kerr, Conway, Tuck, Hammond & Olson · Oregon State University Extension · EC1652

    Reviewed 2025. Accessed October 8, 2026.

  6. Nutrient Needs of Horses ↩

    Oklahoma State University Extension

    Accessed October 8, 2026.

  7. Mineral requirements of sheep and goats ↩

    Shelby Filley · Oregon State University Extension

    Accessed October 8, 2026.

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