Q: I’m interested in your experts’ viewpoint on feeding before exercise. I know we shouldn’t leave horses with empty stomachs. But if you bring a horse in from a paddock to ride, should you give it a handful of hay or chaff before you actually get on (as my friend does) or is that a bit extreme?
Also, if you feed a horse breakfast containing grain, how long after that are you able to work them?
Tracey, Hastings
Vet Dr Dave van Zwanenberg replies:
Tracey, there is no one-size-fits-all here and it depends on the athletic performance you are after. In answering your question I am assuming you are not talking about elite performance in any discipline (racing, dressage, eventing, show jumping, endurance etc), as competition day feeding for elite performance, and the lead up to it, is a specialist subject and very dependent on the horse, its response to certain feeds and the specific type of work, duration and intensity required.
In general terms for the average sport horse prior to routine exercise, the following is true. The idea of feeding prior to exercise comes from trying to reduce acid splash in the stomach, and preventing ulcers in the top third of the stomach.
In the horse, the top third of the stomach has a lining that is very similar to skin. The bottom two thirds are much more like our own stomachs and mucosal, so capable of dealing with stomach acid.
Acid secretion happens towards the bottom of the stomach and is relatively continuous. Horses being a browsing-style feeder means there should be a relatively steady input of fibre into the stomach.
Unlike human stomachs that can cope with being empty, a horse stomach fares best when there is a constant fibre mass present, with the fibre that is exiting the stomach being replaced by new stuff from the top. The fibre mass is a physical block preventing the acid from the lower portion of the stomach touching the walls at the top of the stomach and causing ulceration.
During exercise, the stomach contracts slightly, and this along with the physical movement of the body increases the risk of acid splash from bottom to top – thus having a stomach full of fibre helps to prevent this.
Added to this, the saliva from incoming feed also helps to buffer any acid reaching the top portion of the stomach.
If you pull your horse out from the paddock and tack it up to ride, then in essence this is the scenario in the stomach. If, however, you pull your horse out of the paddock and spend an hour or so grooming and working around your horse prior to exercise, or you have the horse in transport for a reasonable period (in my local area this could be a trip to hack our in Woodhill forest), then a small feed of a handful of hay/grass prior to exercise will help ensure the stomach has a decent fibre mass prior to exercise.
Outside of certain elite performance codes (eg. racing) there is no detrimental effect from a gut full of hay to expected or perceived performance
The feeding of grain prior to exercise is slightly more of a hot potato. The fibre portion of the feed will still act as a fibre mat and prevent acid splash. The higher energy content of the hard feed will provide a more readily available supply of energy.
In some horses this is helpful in providing more “energy” in their movement, in others it may be a case of check your life insurance policy and hang on to the snorting 19-hand fire-breathing monster (or anywhere in between these two extremes).
Peak glucose concentration occurs about one to two hours after a hard feed. So in this case, the answer is ‘it depends’ and probably: know thy horse first before trying it out.
Nutritionist Dr Lucy Waldron replies
Horse are evolutionarily adapted to run from predators at a moment’s notice under all kinds of circumstances, and carry the majority of their feed (for 2-3 days) in their hind gut.
Typically, any feed in their stomach only remains there for short periods, as their stomach is relatively small, about the size of a football.
So, the bulk of feed only remains in the stomach for 20-60 minutes (depending on the source of feed), according to research. In fact, it takes around 16 hours of complete feed removal to empty the horses stomach (a period of time we use in research to allow scoping for ulcers, so we can see the stomach wall). Given catching, grooming and prep time before riding, your horse should be fine to ride without extra feed. Horses prone to ulcers do need extra care, such as feeding slow-release calcium and fibre generally throughout the day in small amounts.
There are various discussions regarding the time lapse between riding and feeding, which are ongoing. However, if your horse is not doing fast work, then the normal amount of prep time seems to be fine.
We do have to be careful not to project human consumption issues onto our horses – which have a very different digestive system that is adapted for quick flight when necessary.
As children we are always told ‘don’t exercise on a full stomach’ as this is a problem for the human digestive tract. Your horse is very different!
Many owners report issues with bad behaviour is horses at events – and much of this may be due to travelling without access to fibre-rich forage, which is a common practise in New Zealand.
This, plus the excitement of being somewhere new and fun, means the horse will typically evacuate its bowels, which can reduce the levels of fibre in the hind gut, leading to a reduction in calming B vitamins from hind-gut bacterial fermentation.
I feed my horse a haynet whilst travelling and at shows, and there is no data showing that feeding during travel increases the risk of choke (a horse that is going to choke will do so wherever it is – even in the paddock or stable).
