STARCH VS FIBRE - AN EXPERIMENT ON FOALS

I’m a big fan of the Journal of Equine Veterinary Science. One very recent article really grabbed my attention and I will attempt to translate it into more layman terms below. The full article citation is at the end of this post.

The article is titled the super catchy, ‘Growth rates of Thoroughbred foals and in vitro gut health parameters when fed a cereal or an all fibre creep feed’.

Essentially this experiment looked at whether thoroughbred (TB) foals grow as big and as fast when they’re fed an all fibre diet as opposed to a cereal based diet and also whether an all fibre diet made any positive difference to their gastrointestinal health.

The very first two sentences of the article verbatim are: “Traditions and the economic advantage when producing big athletic TB yearlings for sale, encourages owners to feed high levels of cereals. Such diets can predispose gastric ulceration and developmental orthopaedic diseases, impacting negatively on future careers.”

This first line explains why feeding a lot of cereals/grains (i.e. sugar and starch) is attractive - big foals get more money at sales. What’s also known is that feeding large amounts of cereals can negatively affect young horses as it predisposes them not only to gastric ulcers, but also to growth-related disorders, particularly developmental orthopaedic diseases.

Given breeders want to grow large foals/yearling, if they don’t feed grains then they’re going to have to significantly increase the amount of fibre that’s fed. Many TB breeders are reluctant to do this though as they believe that the lower energy and protein digestibility of fibre feeds reduce growth rates and cause ‘hay belly’ in comparison to high starch (cereal) diets.

Groups of foals in this experiment were put in matched pairs (one eating a grain-based diet and the other a fibre-based diet) and weight gain, height, girth body length were measured each week. A range of lab-based tests for gut health were carried out at the same time.

Results demonstrated that comparable high growth rates can be achieved and achieved in the same amount of time when they’re fed a fibre diet as when they’re fed a cereal-based diet.

The laboratory gut-health test results suggested that the fibre-fed group maintained a healthier gut environment by raising pH and lowering lactate production compared to the cereal-based group.

These results work to dispel the industry-held belief that feeding high levels of fibre to foals will produce pot-bellies and not sustain desired growth rates.

Naturally all of this is extremely interesting in terms of feeding foals and young horses, but further to that I think the results of this study can be applied beyond just this experiment.

If while growing there is a better and healthier way to provide calories and energy to a horse, can this not also be translated to our adult horses? Grains shouldn’t be fed to horses with laminitis and horses with metabolic diseases. Starch is known to irritate, if not cause ulcers. Horses fed high grain diets are likely to chew less, drink less and spend less time grazing. Horses fed a high starch diet are more likely to suffer from colic. A high starch diet has been shown to have adverse effects on microbial populations in the hindgut. The list goes on and on.

I’m not quite sure then, why so many of us still choose to feed high grain, high starch diets when there are so many brilliant, effective and affordable alternatives. And just because you’re not feeding the obvious boiled barley, pollard or cracked corn, if you’re feeding a premixed, ‘complete’ feed I urge you to turn the bag over and read the ingredients. Even products that contain the words ‘Cool’, ‘Calm’ and ‘Low GI’ almost all contain large amounts of grains/cereals/sugars/starches. In fact the overwhelming percentage of all premixed complete feeds contain a huge amount of grain.

Making the switch may seem difficult, but it doesn't need to be. There are plenty of resources available to you online or feel free to get in touch with me and I can help you with the transition.

I highly recommend you to read the full article, it contains a great deal more information than what I’ve posted here.

Moore-Colyer M, Tuthill P, Bannister I, Daniels S, Growth rates of Thoroughbred foals and in vitro gut health parameters when fed a cereal or an all fibre creep feed., Journal of Equine Veterinary Science (2020), doi: https://doi.org/10.1016/j.jevs.2020.103191.