According to Pavo's roughage monitor, grass and roughage in the Netherlands almost always have low concentrations of the trace elements zinc and copper. These minerals are involved in important bodily functions. They do not need to be present in large quantities in the diet, but it is important that your horse gets a little of both. Since Dutch soil is often rich in iron and manganese, horses rarely have a deficiency in those elements.

Peat Soil and Sandy Soil

On soils with high phosphorus, high lime, or high organic matter content (such as peat soils), a zinc deficiency is often observed. Copper deficiency is also common in soils with high organic matter content. A deficiency in copper in grass can also be caused by high levels of protein and sulfates. This is often seen in sandy soils. This means that in large parts of the Netherlands, there is too little copper and zinc in the grass and therefore in the hay.

Importance of Zinc and Copper

Zinc and copper are absorbed in the body through the same pathway. This means that if there is too much zinc in the roughage, copper will be less effectively absorbed. And vice versa. The ratio between these two trace elements in roughage must therefore be correct. The importance of copper for animals is significant. It affects metabolism, bone development, and the formation of red blood cells. A copper deficiency can lead to anemia, reduced immunity, poor coat, and fertility issues. The growth of foals can also be at risk due to it. Zinc is necessary for protein synthesis and metabolism. It is difficult to determine a horse's mineral status with a blood sample. Often, the body maintains a constant level in the blood. Therefore, hair samples are often a better indicator.

Sufficient Zinc and Copper?

To ensure that your horse receives enough zinc and copper, it is advisable to provide a mineral balancer in addition to good roughage. If your horse receives a lot of concentrate feed (see the packaging for the recommended daily dose), it may already contain sufficient levels. However, many horses receive much less concentrate feed than the manufacturer assumes. This is often healthy, as most horses in the Netherlands are not used for elite sports and the grains in concentrate feed can be stressful. But this means you need to supplement minerals (and vitamins) instead. For horses used recreationally or in basic sports, a mineral balancer alongside roughage is usually enough, especially for hardy breeds. The advantage of a balancer is that trace elements like zinc and copper are fed in the correct ratio and do not compete with each other.

Further Supplementation?

During certain periods, it may be wise to offer your horse extra minerals. For example, during shedding, periods of low immunity, or during pregnancy and lactation. If you want to give your horse some extra minerals, you can do so in the form of a mineral supplement from Bering Sea water. This supplement contains all the minerals and trace elements that your horse may need. You add this mineral supplement to a bucket of drinking water, possibly as part of a mineral buffet. Your horse can then choose whether it needs the extra minerals. Always ensure that your horse has access to fresh water without additives so it can make the choice. Note: Bering Sea water contains many different minerals and trace elements, but no vitamins. Therefore, it is not a complete replacement for a balancer pellet.

Never add copper and zinc to your horse without justification! Do not experiment with this on your own, always consult with your veterinarian first if this is necessary.

Sources: Roughage monitor Pavo Van Bömmel-Wegmann, S.; Gehlen, H.; Barton, A.-K.; Büttner, K.; Zentek, J.; Paßlack, N. Zinc Status of Horses and Ponies: Relevance of Health, Horse Type, Sex, Age, and Test Material. Vet. Sci. 2023, 10, 295. https://doi.org/10.3390/vetsci10040295