1. STAGE OF GROWTH
It is irrefutable, because of evolutionary adaptations to semi-arid environments, that forage suitable for the equine mono-gastric style digestive system needs to be very high in fibre. Grass that is suitable for equine is very different to that of dairy cow grass.
Equines are Graminivores (GRASS eaters), a sub-section of Herbivores (general plant eaters):
“A Graminivore is a herbivorous animal that feeds primarily on grass, specifically "true" grasses, plants of the family Poaceae (also known as Graminae)”. Their dentition is specifically adapted for grinding the ‘abrasive silicates’ in grasses.
This is VITAL to keep this digestive system along with the horse’s metabolism, functioning optimally.
Did you know that the larger the herbivore the higher in coarse fibre their diet needs to be. Horses are large mono-gastric mammals (up there with rhinos!)
Wild/feral horses live on vast areas with very low stocking rates – other than in Spring, they have little access to green, vegetative grass, because where they live, it hardly ever rains.
Hence domestic breeding horses, growing youngsters and elderly horses do well on grass which is at a slightly younger stage of growth for part of the year but NOT all year round.
For the average recreational horse or pony, to stay reliably calm and healthy, mature grass or hay should form their staple diet.
Green, growing grass is hard work for the horse’s metabolism to handle compared to stalkier, yellower grass. This is why when horses have issues, taking them OFF green, grass works so well – it has the effect of giving their whole metabolism a rest.
Horses whose metabolism is already compromised (as in EMS, laminitis prone, head-shakers, pasture heaves, show signs of increased excitability like spooking) do better on more over-mature grass that has well and truly finished growing.
Grass when it is young, green and growing, has two major disadvantages for domestic horses:
- The Dry Matter content is very low so it DOES NOT PROVIDE ENOUGH FIBRE – a major reason why so many horses have digestive issues and develop ulcers
- The nutrient composition fluctuates with the season and the weather, making it a wildcard in your horse’s diet.
Grass (of any species) when it is in growth mode is very unbalanced forage (to be covered in more detail in future posts):
• Low Dry Matter content
• Excessive Crude Protein/Nitrogen levels
• Mineral imbalances: high potassium concurrent with low sodium & magnesium
• Sugars - as leaf area increases so does capacity to photosynthesise and manufacture sugars to fuel growth
When growth is inhibited - by drought, growing in the shade, low night-time temperatures, frosts or consecutive cloudy days these items accumulate in the plant until conditions favour growth.
While his metabolism is functioning normally the horse appears to cope well consuming unbalanced forage because his internal homeostatic mechanisms are working optimally and can maintain equilibrium despite the imbalances and fluctuations.
However, with continuous consumption of such unbalanced forage, their metabolism sooner or later reaches ‘tipping point’ and can no longer cope. This is when you see the evidence showing up on the outside of the horse with changes to health, movement and behaviour.
The take home message because we are not keeping horses in anything like their ‘natural’ environment, no matter what your grazing situation, is to do what you have to do to make sure that your horse’s forage predominantly consists of mature grass or HAY .
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