Why should we be fanatical about forage?

For every class of horse, a good diet should always be based around forage; it’s what they have evolved to eat! In this article I will guide you through the main reasons why we should all be scrutinising the forage that we feed to our horses by explaining how certain aspects of forage can have a significant impact on the overall health of your horse and what you should look for when sourcing it to enable you to become a forage connoisseur!

Through hind gut fermentation horses are able to efficiently extract available calories from large quantities of high fibre forage.  In fact many equines, even in medium work and when fed sufficient quantities are able to perform on a diet based solely around quality forage.  But not all forage is created equal!  Pasture quality can range enormously depending on grass species and how it is managed and hay or haylage can vary hugely in overall quality, consistency and nutrient availability depending on how it was grown, harvested and conserved. 

You owe it to your horse to be quite obsessed about the quality of the forage that you feed it.  Forage could form up to 100% of its total feed, and so it could be where all of its protein comes from!  If you have a growing youngster, performance horse or broodmare, their protein requirements will be significantly greater than your friends’ 15 year old happy hacker.  Did you know that the ‘crude protein’ fraction of the forage is actually made up of ‘true protein’ and ‘non-protein nitrogen’?  It is this mix that gives an indication of the ‘quality’ of the protein in the forage.  True protein consists of chains of amino acids.  Essential amino acids must be present in the diet (primarily from forage) whereas non-essential amino acids can be created by the animal providing there are adequate amounts of essential amino acids.  Non-protein nitrogen or NPN may consist of unbound amino acids, nitrates and nitrites.  The horse’s body must work hard to detoxify the NPN and so health problems such as poor immune response and kidney/liver stress could occur when the horse is exposed to high levels of NPN.  So how do you know what the protein quality of your forage is?  Firstly, reputable suppliers of commercially available forage should provide a yearly analysis.  Not all will go into detail about the ‘quality’ so it is worth enquiring should you have concerns.  If there is no analysis available or you make your own forage there are many companies offering low cost analysis services but try to choose one that is geared towards horses and not cows!  Secondly, growers of forage can influence the quality of the protein contained within their crop through simple good management practices.  For example, unbalanced soil fertility is typically the cause for high levels of NPN.  Soil, as a living ecosystem should be well cared for just like any other living thing.  Applying too much of the wrong type of fertiliser or even not applying any can result in deficiencies or excesses of minerals which are then taken up by the grass.  It is important to remember this when managing your own pasture as overgrazed, compacted or waterlogged ground could impact on the quality of the grass that grows.  Applying good old fashioned farm yard manure in the autumn and resting fields are good ways to ensure that you are getting the best from your grass, after all it’s the cheapest feed you’ll find! 

As horses spend most of their time eating forage it is important to think about its hygiene quality.  Grazing fresh grass is of course dust free but even the sweetest smelling hay will have some degree of dust, mould and fungal spore contamination, along with dust mites and their associated faeces!  Hay is never 100% dry, it can always absorb moisture from the atmosphere and it is this combination of oxygen and water that allows mould and fungus to develop.  Most horses will appear unaffected by dusty hay whereas others will have a mild occasional cough and nasal discharge, and some will have severe clinical symptoms and a veterinary diagnosis.  But what is going on under the surface in these horses who don’t suffer enough for a diagnosis?  What are the implications of long term dust, mould and fungal spore inhalation on performance and health?  Many people choose to soak hay which will alleviate symptoms but this can be hard work and will allow water soluble vitamins to leach.  Another option is to feed haylage.  In the absence of oxygen, mould and fungus cannot grow and its slightly damp nature makes it dust free.  Good haylage will be wrapped or bagged sufficiently to ensure no air enters which would result in aerobic spoilage.     

For generations hay has been the preferred forage choice.  Up to 100 years ago, fields were small and pasture was mainly comprised of native slow growing grass species interspersed with wildflowers and herbs.  Sadly, much of this traditional hay pasture has been lost due to agricultural intensification and replaced by modern varieties of faster growing grass.  Farmers were able to cut, dry and bale these small fields within narrow windows of good weather.  It is not economical for farmers today to produce hay from our large fields of high sugar varieties of grass intended for cattle.  For this reason, it can sometimes be hard to find a regular supply of good quality small bale hay that is relatively dust free and sweet smelling.  But if you can source good small bale ‘meadow hay’ and your horse or pony is sensitive to sugar through either being laminitic or insulin resistant then there is a chance that the Water Soluble Carbohydrate (WSC) content may be over the recommended 10%.  Ryegrass hay is even more likely to be high in sugar as Ryegrass has higher sugar content than other types of grass.  Soaking however will leach out some of the sugar but it is important to remember that after 6 months storage hay will already have a low vitamin content and soaking will reduce this even further.  Haylage has higher vitamin content and lower sugar content than hay.  During fermentation, the naturally present bacteria utilise the sugar present as an energy source during replication and break it down into Volatile Fatty Acids which gives haylage its wonderful smell.  Well-made high fibre haylage with a dry matter content of around 70% is therefore a perfectly safe option to feed to sugar sensitive horses.

When sourcing haylage, it is worth investigating the dry matter content.  Haylage which is baled too early resulting in low dry matter content will have a lower pH (more acidic) than haylage baled at around 70%.  Acidic haylage with a low dry matter can unbalance the gut and should be avoided.  Haylage should always be cut at a late stage of growth and have visible seed heads present to ensure it is high in fibre and relatively low in energy; haylage of this type will not cause hot behaviour!

So to conclude, there is a lot more to forage than first meets the eye and for the overall health of your horse it is worth regarding forage as a fundamentally vital aspect of a good diet; it is not simply gut fill!  We all have a choice, so use it!