What feed and supplements for optimal fertility of breeding stallions?

Just like broodmares, breeding stallions may sometimes need some extra support. Especially if they are also used in sports or do a lot of breeding. Of course, not everyone has a KWPN breeding stallion in the stable, but there are quite a few people in the Netherlands and Belgium who breed with, for example, Shetland ponies or their own crosses. What should you look out for in the nutrition for optimal fertility of a breeding stallion?

While stallions do not carry the foal and therefore do not need to receive the building blocks for, for example, the skeleton of a foal like broodmares, they still have special nutritional needs. These are mainly related to fertility.

Optimal fertility of breeding stallions

You want a breeding stallion to be as fertile as possible. This is to prevent disappointments and a lot of effort, energy, and costs for veterinarians and travel for both the stallion owner and the mare owner. In some breeds, such as Shetlands and Friesians, the sperm quality of stallions is not always optimal. The sperm cells are not always enough, good in structure, or mobile enough. Especially when the sperm is diluted or frozen for travel, it is important that the quality is very good. The breeding stallion must therefore be optimally fertile. Fertility in humans has been extensively studied. Up to 80% of fertility problems in men are related to so-called 'oxidative stress' and a reduced antioxidant function in sperm. To remedy this, you need so-called antioxidants in the diet. These are vitamins such as vitamin C and vitamin E.

Vitamin E for fertility

One of the most important vitamins for fertility is vitamin E. This applies to both stallions and broodmares. Research shows that giving extra vitamin E in the feed can result in a higher production of sperm cells and a better structure of those sperm cells. The sperm cells are also much more mobile, increasing the chances of fertilization. Vitamin E is found in fresh grass. If your horse is in a nice green pasture all day, the amount of vitamin E they get from grazing is usually more than enough. When grass is dried to make roughage, most of the vitamin E is lost. Hay contains very little of this essential nutrient. This means that you often have to supplement during the winter. Also, if your horse spends a lot of time in the paddock, or on a bare pasture, a supplement is a good idea. The body does store some vitamin E, but it eventually runs out. This is often at the end of winter, just when you want the fertility of your breeding animal to peak. Supplementing with vitamin E in the winter is therefore a good idea for breeding stallions and broodmares. Horses that are in competition have a higher consumption of vitamin E because this substance is also very important for muscle building. Breeding stallions and broodmares in sports therefore have an even greater need.

Keeping the immune system in check

To get a horse as fertile and healthy as possible for the breeding season, it is important that the immune system is also supported. Vitamin E is important for that, but other substances such as plant cannabinoids from cloves and vitamin C also play a role in good immune function. It is also important that your horse (mare or stallion) is not too fat or too thin. A healthy weight is important for low inflammation levels and optimal fertility.

Which vitamin E should you feed?

The most absorbable form of vitamin E for horses is called 'natural vitamin E'. This may sound a bit strange, as vitamin E is a natural substance. But the molecule can be produced in multiple ways, with the structure sometimes slightly different. Many cheap supplements contain so-called 'synthetic' vitamin E. This is often very poorly absorbed by horses. This is less of a problem in humans, as our bodies can use this substance much better than a horse's body. The most absorbable form of vitamin E is RRR-α-tocopherol. This is found, for example, in wheat germ oil. The so-called synthetic vitamin E is the isomer dl-α-tocopherol acetate. This is often found in cheaper vitamin E supplements and is poorly absorbed by horses. It may seem cheaper, but in the end, it is more costly. Besides vitamin E, other antioxidants are also important for better fertility. A good addition is, for example, vitamin C - also found in grass - or strong antioxidants from, for example, grape seed oil.

High doses? No selenium!

Finally, be careful with vitamin E supplements that also contain selenium. If you want to give a horse extra vitamin E because they train a lot, breed a lot, or carry a foal, then a combined supplement is unsuitable. Selenium in high doses is toxic. While you may want to feed quite a bit of vitamin E. Therefore, choose a vitamin E that contains the natural isomer and is free of selenium for your broodmares and breeding stallions.

Read also: 'Better fertility and healthy foals thanks to vitamin E'

Sources

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Contri A, De Amicis I, Molinari A, Faustini M, Gramenzi A, Robbe D, Carluccio A. Effect of dietary antioxidant supplementation on fresh semen quality in stallion. Theriogenology. 2011 Apr 15;75(7):1319-26. doi: 10.1016/j.theriogenology.2010.12.003. Epub 2011 Feb 4. PMID: 21295825.
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Mohd Mutalip SS, Ab-Rahim S, Rajikin MH. Vitamin E as an Antioxidant in Female Reproductive Health. Antioxidants (Basel). 2018;7(2):22. Published 2018 Jan 26. doi:10.3390/antiox7020022

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