Are you feeding your horse enough hay?

Horses have evolved to graze frequently on small amounts for up to 15 hours a day. But today, horses and ponies are frequently stabled for part or all of the day and fed a limited supply of preserved forage, such as hay or haylage. This ultimately restricts their natural feeding pattern. If this is not adequately addressed, it can increase the risk of disease and/or abnormal behaviours.

Historically, the quality of forages, such as grass or hay, was too poor to meet the high energy demands of working horses, so their diet was high in cereal grains. Today, cereals are frequently included in daily rations, although they are now more common in complementary feeds. But this can mean less forage is provided, particularly for performance horses.

If the nutritional or behavioural needs for chewing or eating forage aren’t met, then the health of the horse may suffer. Potential consequences include gastrointestinal diseases, such as ulcers, colic and diarrhoea, or the development of behavioural vices. These needs are now better understood and have been agreed in the form of recommendations recently published in the scientific journal, ANIMAL.

“Significant changes were agreed to the recommendations for feeding hay or haylage to horses” explain Dr Pat Harris. “We now have a much better and deeper understanding of the nutritional needs of horses, so it seemed wise to update the guidance for all those feeding horses to reflect this”. Dr Harris, who is Head of Equine Studies at the WALTHAM Centre for Pet Nutrition, joined other equine nutrition experts to review the large body of research. “Together we agreed to update the recommendations, which we hope will ultimately improve the health and welfare of all horses”.

In Europe, feeding haylage is increasingly common. It is not unusual for owners to underfeed haylage as it is commonly used to replace hay on a weight for weight basis, or when there are concerns over potential weight gain or unwanted behaviour due to its higher energy value. With the new minimum recommendation for forage intake increasing dramatically to 15g dry matter per kg body weight (g DM/kg BW) from 10g based on this review, it is even more important to ensure horses are fed sufficient forage, especially haylage.

But what does this actually mean?

"Ultimately this translates as an increase in the minimum amount of hay for a 350kg pony from almost 4 to nearly 6kg per day (assuming 90% dry matter), or a rise from 5kg to 7.5kg for haylage (assuming 70% dry matter)” highlighted Dr Harris.

Obviously, for a larger thoroughbred horse the increase in daily amount of haylage is more dramatic .

A 550kg thoroughbred requires an additional 4kg to meet the minimum recommendation of nearly 12kg (if the dry matter content is 70%).

To further recreate the natural feeding behaviour, food should ideally be freely available through the day. When this is not possible, at the very least, horses should not be left without the opportunity to eat for more than 4-6 hours. Although different recommendations were made for those horses who require a dramatic reduction in calorie intake, the need to forage and chew still remains important.

To read the full review paper,

Harris et al., 2016. Review: Feeding conserved forage to horses: recent advances and recommendations. ANIMAL. Available online.

What is dry matter?

Dry matter (DM) is the content of a feed or forage that remains after the water or moisture has been evaporated. Hay typically has the highest dry matter content, with the new terminology defining this as over 85% DM. Haylage has a much lower DM content that may be as low as 50% according to this new publication.

How do I find out what the dry matter of my hay or haylage is?

Commercially sourced haylage may have the dry matter content displayed on the feed bag or available through the company’s website. However, haylage and hay bought directly through farmers are unlikely to have this information. There are a number of feed analysis services available, and they will be able to give you basic nutrition information for a small charge.

What does g DM/kg BW mean?

“g DM/kg BW” means how many grams of dry matter you should feed per kilogram of your horse’s bodyweight.

How do I calculate how much DM my horse is getting?

To calculate the minimum value for your horse, multiple their bodyweight (in kg) by 15. This is how many grams of DM they need a day. If you know the DM content of your forage, multiple the grams by 100 and then divide by the percentage DM. For example, if a 500kg horse is fed haylage with a dry matter content of 70%, it needs 500 x 15 = 7500g of DM a day. For this horse’s haylage, this would mean feeding 7500 x 100 ÷ 70 = 10714 g or 10.7kg of haylage a day.