Carbohydrates Digestion- Behaviour Responses
The primary source for feed for most horses is pasture. To understand their digestion, firstly we have to start with understanding what is happening in the grass. Grass grows by way of a process called Photosynthesis, and to do this it needs sunlight, warm temperatures , also moisture and carbon dioxide from the air ( yes really that gas that many think is so bad for the world!). In the presence of chlorophyll (the green colour), the plant converts those factors into growth above and below the ground and development of seed .
In winter, the cooler temperatures slow down this process but when spring comes with its warmth, extra sunlight and rainy days the processing increases and as a result, the starch and fructans (sugar) are produced. These are the carbohydrates of pasture.
New Zealand pasture is an important part of the business of the country, so a lot of development has gone on to create grasses that will create good milk and meat quickly and effectively. That makes much of the grass available to horses very effective in the photosynthesis, and therefore high in these carbohydrates.
The issue with the elevated behaviour reactions of horses to grass growth, particularly in Spring, is due to the higher sugar level – fructans . What happens in the spring is not just that the grass growth becomes more active, but also due to the fact that the mornings are cooler , the sun is up and photosynthesis starts, but the starch is still a bit slow as it needs heat. The fructans is up and going and as the growth hasn’t started up (also needs more warmth) the plant stores the sugar and so the stem has a high level . As the day warms up both starch and sugars are increasing but more in balance, and they are being used up in the growing process. When night comes the process stops, neither sugar nor starch is produced and it has been mainly used up in a warm day to grow the stems.
Horses do get affected by the higher fructans as they have difficulty digesting these sugars which often pass undigested into the hindgut where they cause hindgut acidosis. This causes discomfort, even pain. So their behaviour changes, although actual responses will vary as horses are all different. The grass gets more balanced as spring moves into Summer and also the horse becomes accustomed to the better pasture.
Note fructans can be high in hay, depending on when it is cut, and it can stay easily stored in the hay stems. However it is water soluble and so soaking or washing the hay will reduce the levels of it.
While it is ideal to have pasture sown with species more suitable for horses, very few can do that. So horses that are susceptible to reacting badly to these fructans need to be kept off the pasture when it is high, graze them at night, bring them inside or off the grass in the very early morning (a pen maybe ) and give them soaked hay instead. As Spring progresses into Summer gradually let them out more early - starting evening and then late afternoon, until they can adjust to being out all the time. Horses do need sunlight to create certain vitamins.
However another solution is to assist horses with the digestion of these sugars and starches. Scientific tests have shown horses can be assisted to digest them by giving enzymes called alpha amylase and beta glucanase ( Richards , Choct et Al ), That is why we created Vetpro Digest Rite, it contains those enzymes as well as prebiotics called mannan oligosaccharides to enhance the gut flora and improve efficient absorption, rice bran with gamma oryzanol and a silicated oxide toxin binder. This unique combination has clearly shown to improve the Spring behaviour of so many horses and assist with many issues relating to digestion of carbohydrates, whether from grasses or grain ingestion.
Grains provide starches and sugars, often to a much higher degree. The issues within the gut are similar; they can also pass though the fore gut without digestion and absorption and therefore create acidosis in the hindgut. Again the active ingredients of Vetpro Digest Rite will assist and the Performance variety is balanced towards assisting the carbohydrate digestion of grain, the Sport variety is balanced towards horses mainly on pasture.
Horses that are overweight, sometimes of a chunky body type, are more vulnerable to carbohydrates and may develop laminitis (founder). A more drastic locking up is required, the weight must absolutely be reduced and again feeding both the enzymes mention above and the oligosaccharides can reduce the negative effects of the founder. Animals with this issue should be presented to a veterinarian for diagnosis and treatment.
Don’t be misled into “the horse is behaving badly because the spring grass has toxins” myth , it is particularly the fructans, but also the starches that is the main cause of the Springtime dances.
Toxin binders are the latest trend product mainly not required by horses on normal pasture fed fresh feed.
These toxin binder products were designed primarily for cattle as certain natural fungi in grass inhibited the performance of the feed intake, the pasture was less efficient in providing full nutrients and so, for example, the cow was less efficient in producing its output. The health of the animal itself was not reduced (not toxic), the addition of the binder made the factory process of the animal more successful.
A toxin binder will bind fungi present in mouldy feeds , such as grains, but also poorly stored hay etc. Horses that ingest mouldy feed or toxic plants , or are sometimes susceptible to the black seed heads of paspalum, do benefit from a toxin binder . However these horses are sick and appear so. They don’t rush around in an excitable way. More importantly they need the services of a veterinarian
The main area of a toxin binder in horses is when they are grazed on endophyte rye grass . This is a type of grass used predominately for cattle pasture and the endophyte is a fungi that is deliberately present as it prevents the stem being eaten by beetles, weevils and other bugs and so debilitate the quality of the pasture. This endophyte can release neurotoxins and it is mainly the LolitremB that is harmful to susceptible horses . It causes a condition known as staggers and tends to happen in the autumn when the grass is short and the animal grazes the low stem. However many modern pastures are being sown with endophyte Rye that does not release LolitremB . Normal pasture and any grass most of the year, do not release toxins that cause negative behavior patterns .
The solution to problems of carbohydrate digestion is to reduce the intake especially when the pasture is high in sugars. Wash all hay. Reduce the grain intake, if a high level is needed for energy then breakdown into small feeds but spread out throughout the day. Alternatively assist the digestion with enzymes and prebiotics such as those provided in the product VetPro Digest Rite.
Click here to read about Digest Rite- A multi-formulated supplement to assist with dietary related problems, such as staggers and excitability.