Autumn and acorns...

In autumn, there are many acorns on the ground, mainly due to storms and normal autumn weather.

Acorns raise many questions, and as horse lovers, we are very concerned about this topic and regularly receive warnings about it.

🔸Are all these warnings justified?

🔹And what about tannins?

Here is a brief summary about acorns and tannins.

🌰Acorns = energy bombs: ~54% carbohydrates (high in starch, low in sugar), ~30% fat, ~7.5% protein + vitamins/minerals and lots of tannins/antioxidants.

=> In large quantities, they are almost a "concentrated food source".

Why should one be careful?

🔸Starch spikes → difficult for sensitive carbohydrate metabolism (IR/EMS).

🔹High calorie content → "makes you fat" without sufficient exercise.

🔸Tannin content → excessive consumption may irritate the intestinal wall and overload the liver/kidneys.

🔹Risk group: hungry horses, horses with limited roughage intake or bored horses (who deliberately 'go searching for acorns').

Tannins: it all depends on the type

Condensed tannins (especially esparcette): promote healthy intestinal flora, can inhibit worms, protect proteins and provide antioxidants.

Condensed tannins are large, stable polyphenols. Unlike hydrolysable tannins, they do not have a carbohydrate core and cannot be easily hydrolysed by stomach or intestinal enzymes.

They therefore have a beneficial effect on the intestinal flora. This is one of the reasons why I am a big advocate of sainfoin in basic supplementary feed.

Hydrolysable tannins

These are found in acorns, oak leaves and walnut leaves. In small doses: astringent, antioxidant and mildly anti-inflammatory. In large doses: toxic to the liver and kidneys. Irritating to the intestinal wall. Hydrolysable tannins are a type of plant polyphenol (tannin). As their name suggests, they are hydrolysable, which means that they can be broken down into smaller molecules by water or enzymes.

Chemically, they consist of a sugar core to which bile acid or ellagic acid is bound. Through hydrolysis (= breakdown in the digestive system), they are broken down into sugar and phenolic acids.

Conclusion

A few ripe acorns = generally no cause for concern.

Green/unripe acorns in large quantities = to be avoided.

So be careful, especially with unripe green acorns. A few acorns are almost good for your health, but in large quantities they can cause acute or more hidden symptoms.

When it comes to tannins, it all depends on the type: some can be consumed without any problems, others with great caution, or not at all!

Practical considerations

Limit access as much as possible, but above all, provide sufficient hay and distractions.

Karin

Equine Naturelle