At first glance, adding chopped fibre to the bucket feed may seem a bit superfluous. To some, it may feel like the garnish to the main meal; for others, it’s something they do because they’ve been told it’s important, but without really understanding why. Here we explain the important role of chopped fibre and why horses and ponies with EMS and PPID may particularly benefit from chopped fibre as part of their bucket feed.
What does adding chopped fibre do?
The addition of chopped fibre slows the rate at which feed is consumed, also referred to as the rate of intake. Studies show it takes horses significantly longer to consume pelleted feeds if chopped fibre is added (Ellis et al., 2005). In this study, the addition of chopped straw, at an inclusion rate of 20%, to a ration containing pellets and other chopped fibres resulted in significantly longer eating periods and increased the number of chews. To put this into context, a scoop of high-fibre cubes weighing 1.5 kg would require 300 grams of chopped straw to achieve a 20% addition. More chews result in more saliva, which is a natural buffer to acidity in the digestive system. The more we can do to increase the number of chews the horse makes, the more we’re helping to maintain a healthy gut.
So does the fibre type matter?
Studies have shown that straw is consumed significantly more slowly than hay (7.9 g compared to 14g of dry matter per minute) (Dulphy et al., 1997), and a more recent study by Jansson et al. (2021) found that 50% wheat straw fed with haylage was consumed more slowly than haylage alone. Ellis et al. (2005) added straw to rations that already contained chopped alfalfa and saw a further increase in the time taken to eat the ration, and so yes, the type of fibre added does make a difference!
Are there benefits to slowing intake as much as possible?
The slower rate of consumption of straw mixed with haylage resulted in a lower insulinaemic response – the level of insulin the horse produces to manage the rise in blood glucose levels after eating. In fact, in the evening, when the rate of intake was slowest, there was no significant increase in insulin levels at all. This study was carried out in horses considered to have relatively normal insulin sensitivities, but this effect could be even more beneficial to horses and ponies with insulin dysregulation (ID). ID is associated with diseases like PPID and Equine Metabolic Syndrome (EMS).
A published study (Macon et al., 2022) showed that horses with ID had a greater insulinaemic response to as little as 0.1g/kg bodyweight of non-structural carbohydrate (NSC) compared to horses without ID. NSC is the combined values of sugar and starch in a feed, and a level of 0.1g/kg is very low. A key point from this study is that all horses consumed the feeds being tested in around 10 minutes, which is fairly typical for a bucket feed. This finding, combined with the findings from Jansson et al’s study, highlights the importance of not only using low NSC feeds but also slowing the rate of intake as much as possible when managing horses with ID.
This is where the use of chopped fibre with a supplement or balancer has an important benefit over other forms of fibre. Obviously, a supplement is usually the lowest starch and sugar option, but it has to be mixed into something, and the extra chew time generated by chopped fibre rather than mashes, for example, is a rationale for using chops. We also need to consider what the sugar and starch content of mashes would be, too!
Key Concepts to Take Away
- The use of feeds with higher levels of NSC can reduce insulin sensitivity in any horse, even youngstock, which have been shown to have reduced insulin sensitivity when fed higher levels of starch-based feeds
- Horses and ponies with ID are more likely to have exaggerated insulinemic responses to even very low levels of NSC intake
- A slower rate of intake can help to modulate the insulinemic response
- Consider using straw both in the bucket feed and mixed with other forage to slow the rate of intake and therefore reduce the insulinaemic response
- Whilst these studies use small numbers of horses and ponies, they are published in peer-reviewed journals and so provide us with valuable insights to how we can best manage our horses and ponies.
