Forages ‒ the leaves and stems of plants such as grasses or legumes available to horses as fresh pasture or as preserved hay ‒ make up the foundation of the equine diet. Depending on the species and material of the plants, they can provide almost all of the nutrients required by most horses: the calories and protein, as well as many of the vitamins and minerals.
Forages are also vital to provide fibre that is required for digestive tract health. Recall that horses have a complicated digestive tract that has a small stomach suited to trickle feeding, and well-developed “hindgut” that houses a large ecosystem of microbes that act to ferment the horse’s fibrous diet to provide additional nutrients.
When fibre is lacking in the diet, the natural flow of digestive material through the intestines is compromised and the ecosystem may be negatively impacted, resulting in digestive disturbances such as colic. Of course, the natural grazing behavior of the horse is well suited to nibbling on hay or pasture throughout the day.
In cases when forage quality is low, or a horse’s needs are higher, we may need to add supplemental ingredients or feeds to the diet to meet the horse’s needs.
There may be times when a horse cannot consume hay or any long-stem forages due to poor dentition or jaw issues, feed sensitivities, or a variety of other reasons. In these cases, it is important to ensure the horse is provided with ample fibre and the nutrients that would be otherwise found in hay.
In many cases, horses just simply can’t handle long-stem hay, but could handle chopped, pelleted or cubed hay. This would still provide the same nutritional value and fibre as long-stem hay, but in a way that can be easily chewed, particularly if these were soaked to make it even easier. I would generally recommend this over avoiding hay altogether, simply because the fibre and “scratch” component of the hay particles are good for intestinal health. Also, pound for pound, the nutrition provided in hay products would be the same as in long-stem hay.
If hay is not an option at all, then there are other high-fibre alternative feeds, notably (non-molasses) beet pulp, rice bran or other types of bran. In general, beet pulp has the most similar nutritional profile as hay – with decent amounts of calories (a little more than hay), protein (a little less than hay), and lots of calcium. Beet pulp does tend to be a little on the low side of phosphorus, as well as some vitamins, so careful balancing would be required if that is the base of the diet. Beet pulp also tends to contain higher amounts of iron than hay, so iron intake might need to be monitored.
Rice bran provides the highest amount of protein and calories (per unit weight) compared to most grass hays and beet pulp, and is a good source of both calcium and phosphorus, although phosphorus is higher than calcium in rice bran. This can pose problems if the calcium-to-phosphorus ratio (ideally 2:1) is not corrected with other feeds.
Wheat bran is another higher protein fibre source, although it is very high in phosphorus and low in calcium and can be particularly tricky to balance out that ideal Ca:P ratio.
Just like with hay, knowing what is in the base fibre component of your horse’s diet is vital, and perhaps even more so than a hay analysis because of the risk of unbalanced calcium and phosphorus that we see in these feeds that we don’t tend to see with hay. A good supplement is limestone, which can be added in small amounts depending on how much calcium and phosphorus are required.
You might also need to provide more calories, specific amino acids, vitamins or other minerals – so when working with this type of base you should consider working with a nutritionist to add up all of the nutrients in your horse’s feed to compare them to requirements.
Also, ideally (just like with hay), you would provide the fibre sources free-choice. This may be tricky as most of these feeds should be soaked prior to feeding. I usually recommend offering fresh beet pulp or rice bran at least 2 times per day, and up to 4 times a day in the summer (due to the heat and flies).
It should be also noted that many “complete feeds” offered by various companies may be designed to be provided in place of other forages. These feeds would have added fibre sources already mixed in, and should be safe and balanced to feed on their own. Check with the feed company of your choice to see if that might be an option.
Offering a hay-free diet has its place with some horses, or at particular times in their lives. We tend to take hay and pasture for granted, but it really is an important part of the diet. We can make do without, but it just takes some extra work to get it right.