Text: Hannah Botha
Have you ever heard someone say, “my gelding looks pregnant” or “he isn’t fat; he just has a big belly”? Both comments refer to a horse with a bloated, sagging belly known as a hay belly. Hay bellies occur over time and can accompany a loss of overall condition in the horse, especially over the top line; however, some horses remain in good condition but still have this appearance.
So, what causes this look?
There can be many reasons for a sagging belly, including:
- Worm burdens, especially in younger horses. It’s recommended that faecal egg counts be used to determine the worm burden so that it can be treated if necessary. This is better than blanket deworming. If your horse has a bloated look, always rule this out first.
- In older horses’ conditions such as Cushing’sDisease can cause enlargement of the belly
- Mares who have had larger numbers of foals can have this appearance.
However, the most common cause of a ‘hay belly’ is poor quality hay and/or pasture. Now your hay may look green, smell sweet and have all the hallmarks of great hay, but at certain times of the year, it may not have as much nutritional value. Hays with a high stem-to-leaf ratio (with little leaf) can indicate a mature cut hay, and it’s these cuts that we need to avoid for horses with hay bellies. Overly mature/stemmy hays have high levels of lignin (contained in the stem). Lignin is non-digestible or ‘nutritionally unavailable’ for the horse. Although these mature hays provide a lot of bulk, they don’t give a lot of nutrition. So, to make up for this drop-in value, the horse must eat more hay, which sets them up for a hay belly. Fermentation of fibrous material happens in the hindgut and is performed by microbes, and when large amounts of non-available bulk enter the system, these microbes must work overtime to digest this component fully. As the microbes work harder to ferment the hay, they produce excess gas, and it’s this combination of gas and non-available bulk that produces that hay belly look.
The same goes for pasture. Just because your horses have access all day to a paddock doesn’t always mean it’s providing them with adequate nutrition. For example, in areas of low winter rainfall, pasture quality reduces significantly compared to summer. This poorer quality grass will again cause the microbes to work harder, creating the distension. In this case, additional fibre would need to be provided to compensate for the poor-quality pasture.
So, how do we combat a hay belly?
In an ideal world, testing your hay would be the first step to determining the NDF (Neutral Detergent Fibre). This figure indicates the amount of non-digestible fibre in the hay. Anything over 60% NDF would be a red flag. However, hay testing is not always possible, and thus we need to rely on suppliers for information.
As a rule of thumb, when selecting hays, look for ones with more leaves than stems, indicating a more immature cut. Also, ask your supplier if they can get the stage of cutting details from their farmer to help make your decision easier.
For most of us, however, making do with the hay we can get is going to be our only option. Still, in these situations, there are several things we can do to help reduce a hay belly.
For horses that are generally in good condition but have a hay belly, monitor the amount of hay being eaten, as it could simply be that your horse is over-eating. Round bales left in paddocks can mean that some horses will set up camp around the bale and simply consume too much bulk. For these horses placing hay nets around the paddock will help spread their daily requirement over more hours, meaning they always have access but will not be able to eat as much.
The other factor to consider is the horse’s exercise routine. It stands to reason that if the horse is not working or not working correctly that the development of a good top-line will be hard to achieve. Before changing hay or feed, it’s therefore worth looking at the horse’s exercise routine. Strengthening the top-line muscles will help support the belly, creating a better overall look and reducing the appearance of that hay belly.
For those that have also experienced a loss of condition and/or top-line, you will need to support their roughage intake with high-quality, highly digestible fibre sources. These include hay cubes, chaffs, and beet products. These products not only provide higher levels of calories to assist with weight gain without excitability, but they are more digestible, meaning they won’t cause a hay belly appearance. They also have the advantage of providing more quality proteins. Overly mature hay will have a lower protein level, which can lead to a reduction in muscle tone over the top line, especially in horses that don’t get additional concentrates. However, correct work and adequate nutrition go hand in hand when building muscle. You need both things in place to achieve a good top-line. If you can, changing your hay to a better quality or including higher quality hays such as lucerne into the diet can also help achieve higher calorie and protein levels for increased condition and top-line.
The main thing is not to restrict hay. This is something that could cause further issues, so instead, you want to look at quality but keep the desired daily intake of hay at the recommended amount of 1.5% of bodyweight in roughage per day.
Final thoughts
Hay belly is a frustrating problem to manage, but with time and patience sizeable improvements can be made to the health and appearance of your horse.