Feeding the Pregnant Mare – A Guide to the Best Start for the Foal

Feeding the Pregnant Mare – A Guide to the Best Start for the Foal

Feeding the Pregnant Mare

Feeding the pregnant mare is one of the most important factors for both foal development and the mare’s wellbeing during pregnancy. The mare’s nutrition does not only affect her own condition, but also directly determines the nutritional foundation the foal has even before birth.

The foal’s nutrition begins already in the womb.

Building the Foundation – It All Starts with Forage

The foundation of feeding the pregnant mare is high-quality forage:

  • good quality hay or haylage

  • sufficient energy intake

  • a consistent feeding routine

When the base diet is well balanced, the need for additional supplements remains controlled and the overall feeding plan stays clear.

Minerals and Trace Elements – Small but Crucial

The fetus receives all necessary minerals and trace elements from the mare.

Key nutrients include:

  • calcium and phosphorus (bone development)

  • zinc and copper (tissue development and growth)

  • selenium (part of the antioxidant system)

If the mare is deficient, the fetus will also receive less.

Vitamin E and Selenium – A Direct Link to the Foal

The mare’s nutrition directly affects the foal’s nutritional status both during gestation and after birth.

Research has shown that:

  • selenium intake in the mare directly influences selenium levels in colostrum, milk and the foal

  • the foal’s selenium status is largely built through the dam

  • the newborn foal receives most of its vitamin E from colostrum

  • the mare’s vitamin E level largely determines the foal’s intake during the first days of life

In practice, this means the mare’s nutrition directly determines nutrient availability for the foal.

The Antioxidant System – Why It Matters

Vitamin E and selenium work together in the body’s antioxidant system.

This system:

  • protects cells from oxidative stress

  • supports normal cellular function

  • plays a key role in metabolism

During pregnancy, its importance increases because:

  • fetal tissues develop rapidly

  • cell division is highly active

Adequate intake of vitamin E and selenium in the mare also supports the developing fetus.

 Colostrum – The Foal’s First Nutrition

Colostrum is the foal’s first and most important source of nutrition.

Research shows that:

  • the mare’s nutrition affects colostrum composition

  • vitamin E is linked to colostrum antioxidant content

  • nutrition may also influence antibody levels

Colostrum forms the foundation of the foal’s early nutritional status.

Omega Fatty Acids – Often Overlooked but Important

While protein, minerals and vitamins often receive most attention, the quality of fat is also important.

Omega fatty acids, especially omega-3 fatty acids:

  • are part of cell structures

  • contribute to normal body functions

What Do Omega Fatty Acids Do?

  • form part of cell membranes

  • participate in metabolic regulation

  • are involved in the body’s normal inflammatory response

During pregnancy, their role increases because:

  • fetal tissues and cells develop rapidly

  • the need for cell membrane building blocks increases

Effects on Mare and Foal

Research indicates that:

  • the mare’s fatty acid profile affects the foal’s fatty acid profile

  • omega-3 fatty acids are transferred through the placenta

  • they are also transferred via colostrum and milk

 In practice, the quality of fat in the mare’s diet is reflected in the foal.

Omega-3 vs Omega-6 – Balance Is Key

Many diets contain high levels of omega-6 fatty acids (grains, oils), while omega-3 intake remains low.

The goal should therefore be:

  • adequate omega-3 intake

  • a balanced omega-3 to omega-6 ratio

Good Sources of Omega-3

  • flaxseed / linseed oil

  • chia seeds, hemp seeds

  • algae-based DHA sources

These are also suitable for pregnant mares.

Why Does This Matter?

Omega fatty acids are not just an “extra”, but part of the whole:

  • support normal cell structure

  • are involved in tissue formation

  • are transferred directly to the foal

Together with protein, minerals and vitamins, they form a balanced diet.

The Last Trimester – The Most Critical Phase

The final third of pregnancy is the most critical stage for feeding.

During this period:

  • up to 60–70% of fetal growth occurs

  • the mare’s nutritional requirements increase rapidly

What Should Be Considered?

1. Energy

  • sufficient intake without excessive weight gain

2. Protein

  • high quality and sufficient quantity

  • supports tissue development

3. Minerals and Vitamins

  • especially Ca, P, Zn, Cu

  • as well as vitamin E and selenium

Practical Feeding

As the foal grows, it takes up more space in the abdomen →
the mare cannot consume large meals at once

Therefore:

  • smaller meals

  • more frequent feeding

Simplicity Works

Feeding the pregnant mare should remain simple:

✔️ forage + minerals + protein
✔️ simple additions (seeds, berries)
❌ strong herbal blends

The simpler the feeding, the easier it is to manage.

Water and Salt – Basics Matter

  • adequate water intake is essential

  • salt (sodium) should be part of the daily diet

Often overlooked, but absolutely necessary

After Foaling

A well-fed mare:

  • recovers more evenly

  • maintains body condition better

  • transitions more smoothly into lactation

And most importantly:
the foal’s nutrition does not begin at birth – it begins during pregnancy

Summary

Key principles of feeding the pregnant mare:

  • high-quality forage

  • sufficient energy and protein

  • balanced mineral and trace element intake

  • vitamin E and selenium as part of the whole

  • clear and controlled feeding

Especially: the last trimester is critical

References

  • Pagan, J. D. et al. (2009). Effect of selenium supplementation on mares and foals

  • National Research Council (NRC, 2007). Nutrient Requirements of Horses

  • Hoffman, R. M. (2013). Nutrition of the pregnant and lactating mare

  • Finno, C. J. & Valberg, S. J. (2012). Vitamin E and selenium in equine health

  • BEVA – Colostrum and foal immunity guidelines

  • McKenzie, E. C. et al. (2017). Effects of vitamin E supplementation in mares

  • Burns, T. A. et al. (2011). Omega-3 fatty acids in mares and foals

  • Hess, T. M. et al. (2012). Fatty acids in equine nutrition

  • O’Connor, C. I. et al. (2007). Dietary fatty acids and reproduction

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