Why Feed Chaff to Horses?

What is chaff for horses?

Chaff is quite simply dried forage that has been cut into small pieces, in contrast to the long grass stems in hay and haylage. There are many different types of chaff for horses on the market today, such as chopped hay, alfalfa, dried grass and straw, or mixes of one or all of these. Most are made by forage producers and bagged for ease of transport and to help maintain freshness. Molasses and/or oil or another mixer such as wheat or corn syrup is used to reduce dust and increase palatability. Flavours may be added such as cherry, apple or spearmint and herbs including garlic.

Dried grass is dried at high temperatures which kill any bacteria and spores, but preserve the nutrient value, leaving the forage clean and nutritious.

Many horse owners feed a small amount of chaff to horses just to bulk out the concentrate feed but there are other beneficial reasons for its use. Horses are predominantly fibre digesters or hindgut fermenters. Within the hindgut, are millions of micro-organisms that play a vital role. This is to break down digestible fibre content of the natural herbage diet, releasing energy-giving substances which the horse then uses.
Contrary to some beliefs, fibre is not just a ‘filler’. The hindgut micro-organisms create a delicate microbalance which, if upset, may result in health and performance problems and also may suppress the immune status of the horse, often creating a downward spiral of health problems.

Forage however, must not just meet the needs of the digestive tract, but also those of the respiratory system. Where conserved forage is fed it must be of good quality nutritionally but it must also be clean, i.e. free from moulds and fungi and therefore not compromise respiratory function. The deleterious effects of feeding poor quality forage cannot be underestimated. Forage also provides energy, protein and other important nutrients such as vitamins and minerals and is an entirely natural feedstuff for horses. It is generally well known that feeding plenty of good quality fibre helps to maintain the health of the digestive tract and has an important role in immune function.

Trickle Feeding

Trickle feeding fibre such as chaff (a little at a time) encourages horses to chew, producing much more saliva than when concentrates are fed on their own and this alkaline saliva buffers the stomach acid. The presence of a high fibre feed such as chaff in the stomach helps to neutralise stomach acid. Chaff will also encourage chewing, prolonging feeding time and the production of increased amounts of acid-buffering saliva. Furthermore alfalfa may actually have a more protective effect than other hay-based chaffs because of the high protein and calcium content giving improved buffering properties. Feeding a bowl of alfalfa chaff for horses, or any chaff prior to exercise, may be helpful as this will help to reduce the splashing effect of acid on an empty stomach.

Feeding large quantities of high starch, cereal-based concentrates may swamp the foregut and be rapidly fermented by the hindgut micro-organisms. This may lead to increased acidity in the hindgut, followed by the proliferation of undesirable micro-organisms and the delicate microbial balance is upset. Feeding chaff will slow down the horse’s intake by encouraging chewing, helping the horse to digest the feed properly.

Molasses

Molasses is often added to chaff mixes to reduce dust and increase palatability. Molasses has had a bad press and many horse owners have taken the idea that sugar is bad for humans and also to their horses. Molasses is actually the dark brown syrup-like residue produced as a by-product of the sugar extraction process from sugar cane or beet. Molasses contains roughly 40-50% sugar but is only added to chaffs typically between 10 and 40% The horses natural diet of grass often contains 20% sugar (on a dry matter basis) and horses will consume large amounts whilst grazing, mostly with no harmful effects. In fact a 500kg horse may consume roughly 10kg dry matter (or 50 kg fresh weight) of grass per day thereby eating about 2 kg or 2000g of sugar i.e. two bags of sugar every day! The horse is very well adapted to digest and metabolise sugar as long as it is ‘trickle fed’ (as in grazing) and not offered in one large meal.

Molasses is also present in molassed sugar beet pulp as some is added back during production. Molassed beet pulp therefore contains roughly 20% sugar, similar to grass, but it is fed at much lower rates. Sugar is actually vital for horses as an energy source and the central nervous system –including the brain – specifically requires glucose for energy.

Other benefits of the addition of molasses to chaff mixes is the natural nutrients contained within, such as potassium, iron, calcium, salt and B vitamins. So, molasses for horses is actually useful in moderation as long as the horses’ own natural ability to digest sugar in the small intestine is not overwhelmed. Contrary therefore to popular belief, the typical addition rate of molasses to chaff mixes means that grass usually contains much more sugar than molassed chaffs!

Other ingredients that may be added to chaff for horses include soya oil to increase energy content with some chaffs containing as much as 20% oil but more commonly around 10%.