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Common Myths About Green Grass

1. “Assuming that because horses and ponies can get laminitis while on short grass, that short grass must be high in sugars; with no evidence to support this”.

Analyses that Calm Healthy Horses have conducted over the years prove otherwise. In fact, the opposite is true. The shorter the grass, the lower in sugars – BUT the higher in crude protein.

Short grass has little to no leaf area and grass needs leaf area in order to manufacture sugars. And yet horses frequently tip into laminitis on such grass.

2. “High Potassium in grass or lucerne/alfalfa ‘is of no concern’ as it is ‘easily excreted in the urine”.

It is easy to see how this myth has spread because in the Nutrient Requirements of Horses (NRC) it actually says that ‘excess potassium is excreted readily’ despite the fact that ‘safe maximum tolerable levels for non-ruminants would be 10,000mgs/kg’ which = 1%.......never seen in short or lush green forage, especially in cool, season grasses and lucerne/alfalfa where it is closer to 2% or more, even more (3-5%) in dairy or rye/clover pastures.

One reason why keeping horses on green grass all year round puts chronic stress on their homeostatic mechanisms and starts a cascade of physiological disturbances.

3. “You don’t have to feed hay when there is plenty of grass”.

Actually you do. There is very little fibre (Dry Matter) in short or lush green grass. Around 25% vs 80 – 90% in hay. Fibre content increases with maturity of the plant.

4. “Crude protein supplied in green grass is healthy protein and is all they need”.

The protein in green, growing plants consists of True Protein + ‘spare nitrogen’ – known as Non-Protein Nitrogen (NPN) mainly in the form of Nitrates.

These are NOT useful to the horse at all. In fact mono-gastric animals like horses have ZERO requirement for nitrates so their digestive system is not designed to deal with them at all.

Horses need YOU to ensure they are getting sufficient of all the amino acids which tend to be inadequate in both green grass and hay.

5. “Clovers should be part of the sward in order to fix nitrogen and encourage good growth”.

Horses evolved in low nitrogen semi-arid environments - a far cry from the ever-green paddocks & fields we expect them to graze and be healthy on!

6. “Sugars in the grass are the only aspect of grass to be concerned about..”

Grass needs to produce sugars in order to grow. Horses are healthier on more mature grass which is higher in cellulose from which they obtain most of their energy via hind-gut fermentation.

When grass has grown to the point it has plenty of leaf area and when conditions are favourable for photosynthesis and manufacture of sugars, then consuming these sugars can become problematic for many horses.

7. “Hay is all the horse needs”

Feral/wild horses do not eat green grass all year round, neither do they eat hay or mature, stalky plants all year round.

Because we keep horses behind fences, and thereby inhibit their ability to free range, we need to supply their daily essential nutrients in a supplementary feed. These nutrients include the 5 food groups necessary for good health and longevity– Carbs, Proteins, Fats, Vitamins and Minerals.

‘Good Doers’ need less carbs but still need quality protein, salt, vitamins & minerals. Working horses will need more carbs, protein, salt, vits & mins.

8. “A lush, green ‘meadow’ full of many different herbs and clovers etc is beneficial to the horse”.

Any obscure benefits these plants may have are completely overwhelmed by the enormous imbalances described above that the horse’s metabolism has to unnecessarily process. Horses did not evolve on this kind of forage. Yes their diet was varied – but was SPARSE and harsh not LUSH and easy! Horses evolved a mono-gastric style digestive system best for deriving their nutrition from LOW NUTRIENT DENSITY forage which varied throughout the year with the seasons.

Green grass (short or lush) is actually the most unbalanced forage you can feed your horse. It is impossible to 'balance to' as you can't take the excesses out and it changes with the season and the weather, whereas with hay it is possible as it has finished growing so is more stable.

When you subject the horse’s metabolism to the stressors of high potassium, lack of fibre, high crude protein/nitrogen and sometimes high sugars, in such grazing, it is no wonder there are so many horses with so many debilitating issues. Their metabolism copes until it doesn’t!

The good news is that understanding these points and making appropriate adjustments to MANAGEMENT in order to control the stage of growth and quantities of grass that your horse consumes makes ALL the difference – issues will resolve and you will have a safe, fun, enjoyable horse to ride!

High nitrate/potassium grass
High nitrate/potassium grass

grass which is much lower nitrogen/potassium
Much lower nitrogen/potassium!

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