Forage and Fibre

If hay is being soaked to improve its hygienic status then recommendations are most commonly to soak for between 10 and 20 minutes although some advocate soaking for up to 1 hour. The key point though is that the hay should not be allowed to dry out prior to feeding so once the hay has drained it should be given to the horse.

If hay is being soaked to reduce the sugar content then there are lots of factors to consider not just the timing. Firstly the ratio of hay to water is important and current advice is to use as much water as possible to maximise the leaching of sugar. Some researchers have advocated 10 parts water to 1 part hay but this simply isn’t practical for everyone. The general principle is to use as much water as you can whilst taking into consideration the fact that water is a very precious resource – using rainwater for soaking hay is one possible solution. The other factor to consider is that warmer water will remove more sugar too. Again it is not practical for everyone to use warm water but studies have shown that around 16C was optimum for sugar removal.

If you can use lots of warm water then it is suggested around two hours will help to reduce sugar levels without losing too much dry matter from the hay. Soaking for longer starts to increase losses (Bochnia et al, 2021) so the horse then has to consume more to ensure they receive sufficient fibre intake. In warmer conditions, soaking for more than two hours is also likely to result in the hay starting to ferment and this is not desirable for then feeding to horses. Studies have shown that soaking for longer periods such as 9 hours, also increased the microbial contamination in the hay. Researchers suggest this could potentially cause digestive upsets but how significant this issue is remains to be confirmed as soaked hay has been fed for many years to lots of horses without apparently causing extensive problems. In principle, in cool conditions, it is therefore acceptable to soak hay overnight if you want to but it is important to be aware that the microbial load in the hay will be increased and more is likely to need to be fed to compensate for the dry matter lost from soaking for a long time.

Techniques for soaking hay vary but there are now specialist tanks available that have drains and that are on wheels for easy manoeuvrability. If these are out of your budget range then dustbins or even an old bath can be used too. The benefit of a bath is that it has a plug and so the used water can be removed easily without having to lift or tip heavy containers. It also means the hay can be left in while the water drains off so that it is a bit lighter by the time it needs to be used.

The recommendations for the length of time to steam hay vary according to different manufacturers of commercial steamers. In studies the steaming period was around 50 minutes. If choosing a steamer that advocates less steaming time it is worth asking what research they have done to show the shorter time frames along with the temperature of the steam is sufficient to kill the same levels of bacteria. Although shorter steam times may seem more convenient, it is important to compare their performance. Although steamers are quite expensive to purchase, their performance can not be replicated trying to steam hay yourself.

One study by researchers in Denmark, found that a horse eating straw as the sole or predominant source of forage source was 4.5 times more likely to have gastric ulcers. What often gets lost from this study is the proportion of straw in the ration. In the UK, straw is rarely fed as the sole forage source so this is unlikely to be an issue. Recognising that straw can be useful as a low-calorie forage source for good doers, a study has been published investigating the safety of feeding 50% wheat straw. The research found no increased risk of ulcers from using 50% straw to replace haylage in the ration.

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No, wheat straw is more commonly available in Scandinavia as oats aren’t grown there. In the UK oat straw is usually first choice, followed by wheat and then barley.

Additional concerns may relate to risk of impactions which largely stem from studies published in the 1980s. In more recent studies exploring different types of bedding for horses and their implications for welfare, it is apparent that if horses have access to straw bedding they do move between their hay and their bedding and so the time taken to consume their forage ration is longer. Researchers in these welfare focussed studies advocate this behaviour and highlight that those bedded on shavings do, in some cases, eat their shavings but also spend less time eating which has negative consequences for digestive health. What we want to avoid is a horse or pony eating a large amount of straw in one go and so if it’s part of a mix of forages, this is less likely to occur.  If a horse or pony has poor teeth or a history of impaction colic then straw is probably best avoided if fed in long length. It may still be suitable if chopped and mixed with other ingredients in the bucket feed though. If you are in any doubt please consult your vet.

If your horse has poor dentition or a history of impaction colic then straw may not be suitable but it is worth discussing with your vet as straw isn’t necessarily any more fibrous than some late cut hays. Chopped straw may be a viable option in these scenarios or dampening to soften may help too. As with any new feed introduce small amounts and increase gradually over at least 7 days. Mixing straw with the other forage will help to reduce the amount the horse is consuming at one time – problems typically occur when a horse gorges on one ingredient so the key is to limit the amount they can consume. Horses will often pick through the mix of straw and other forage which is great as it slows their intake even further!

Some horses won’t eat straw, even if there is nothing else on offer. Whilst it might seem wasteful, mixing straw in with other forages can mean it still serves a purpose by slowing the horse down when eating as they sort the straw out from the other forage.

Calculations using typical values for forages show that if straw replaces one third of the weight of an average hay, a reduction in energy intake of 16% is achieved. Obviously replacing half of a higher quality forage such as haylage will achieve an even greater reduction. Interestingly, research suggests that to lose 0.5 unit on a 5 point body condition scoring system is thought to require a reduction in energy intake of 11-15% in the total diet. This makes straw the ideal choice for maintaining forage intake but reducing weight.

Straw has a much lower water-soluble carbohydrate (WSC) content than grass forages so it has less of an impact on blood glucose and insulin levels when eaten. This, combined with a slow rate of consumption meant that in one study, no significant increase in insulin levels occurred in horses consuming 50% straw and 50% haylage. This is really valuable information for managing insulin dysregulated (ID) horses such as those with EMS or PPID.

The hygienic quality of straw can vary, so some care is required when sourcing some for your horse or pony. Straw can be soaked or steamed but if this isn’t practical then chopped straw is available to buy in branded packaging. This will have been dust-extracted and sourced from reliable growers.

Well not themselves no but they do have a population of microbes in their digestive tract that can, and the energy the microbes release from fibre is what the horse uses as fuel for work, maintenance or growth. The other key fact is that the horse’s digestive system is designed to slow the transit of fibre long enough for the microbes to break down the fibre and release the energy – if the horse’s gut was like ours, the bugs simply wouldn’t have time to do their work before the food passed through and out of the digestive system.

Different cuts of hay or haylage can vary significantly in nutritional value, even when harvested from the same field in the same year. This is because the plant’s nutritive value will be affected by its physiological age, i.e., how mature the plant is.

Depending on the weather conditions in a given year, the first cut may be taken as early as mid-May. At this point, the plant is still fairly young and is likely to contain much more leafy material as opposed to stalk and stem. The seedheads may just be emerging and the plant will be more nutrient dense with a higher protein and water soluble carbohydrate (WSC) content. By the time of a second or even a third cut, which could take place as late as September, the nutritional quality of the plant will have dropped.

The maturity of the plant at the time it is cut will also determine how digestible and nutritious it is. A second or third cut in August could be very different to a first cut in August. This is because as the season goes on and the plant matures, it needs more structure to hold it upright, so the amount of fibrous stem material increases. Forages that are harvested as a first cut later in the season when the plant is more mature will often feel stalkier to the touch, with thick, coarse stems, and contain less leaf material. The higher proportion of structural fibre it contains will be less easily digested by the horse and so these later cut, more mature forages are usually more appropriate for good doers as typically they won’t provide as much digestible energy (calories). In contrast, forages harvested when the plant is younger will generally feel softer, containing more leaf, and be more easily digested by the horse. They are also usually more palatable. This means they are a typically preferable choice for poor doers or performance horses, as the horse will be able to extract more benefit from them, as well as being more likely to consume them in sufficient quantities.

However, there are a number of other factors that can also affect forage quality, such as plant species, weather conditions and even the time of day that it is harvested. For this reason, conducting a forage analysis is the only way to know what your forage is providing and determine its suitability for an individual.

Er, no it doesn’t, well not much anyway, not by the time it has become a feed for horses and other animals. The sugar has nearly all been taken out for use in human foods and what is left is a really fibrous pulp. The pulp itself is less than 5% sugar so less than half the simple sugars found in most hays. Some sugar beet pulp has molasses added to make it a little bit sweeter and more palatable but unmolassed sugar beet pulp is a really great source of highly digestible fibre with a low sugar content. The fact that it is so digestible means it is effective at promoting weight gain safely. As it is fed soaked it can be used in a dilute form to dampen feed and hide supplements for horses and ponies that require a low sugar diet.

Haylages are typically baled at around 40-50% moisture and tightly wrapped in around 4-8 layers of stretch polyethylene plastic film to exclude oxygen and allow fermentation to occur. Common wrap colours include black, white and green. Although there is limited research specifically on haylage, studies in silage suggest that film colour has little effect on the chemical composition or nutritional quality of the conserved forage (Snell et al., 2003).

However, darker coloured films may absorb more heat from the environment. Snell et al. (2003) noted in the study that the black plastic-wrapped bales heated up more quickly on the surface than the lighter coloured bales, particularly during the middle of the day when there was a marked difference in temperature between the bales with different wrap colours. Hotter surface temperatures may increase the permeability of the plastic wrapping (Borreani and Tabacco, 2008), potentially increasing oxygen transmission and the risk of mould growth.

That being said, research carried out in temperate climates similar to in the UK found no significant effect of film colour on silage quality or mould development (McEniry et al., 2011), although further research in this area would be beneficial. This suggests that under typical UK conditions, the choice of wrap colour may not have a major impact on forage quality.

In hotter climates where radiation from the sun is greater, it could be preferable to use white or lighter coloured films to potentially reduce surface heating and oxygen passing into the bales. It’s important to note though that other factors like storage conditions, thickness of the wrapping, and number of wrap layers are likely to influence the quality and stability of the forage to a greater extent than wrap colour alone.

Rich can mean different things to different people but if we take protein as a measure of richness, most alfalfa chaffs in the UK have a protein level of between 12 and 15%. This is comparable to a conditioning cube or competition mix. Most importantly a percentage of protein means nothing until it is considered in conjunction with how much is fed. One scoop of a 12% alfalfa chaff weighs around 400grams and so supplies 48 grams of protein which equates to between 6-8% of a 500kgs horse’s daily maintenance needs. Very few people feed more than a couple of scoops per day and so are only supplying around 12-16% of their horse’s total requirement – certainly not a case of being too rich for most horses! Confusion is often caused by the fact that alfalfa is used as a hay in the USA and Canada and so is fed in much, much greater quantities – maybe 10kgs a day. This fact is often missed when information is posted on the internet that relates to feeding alfalfa.

Oatfeed often causes confusion especially when it’s included in feeds for horses in light work or those prone to laminitis. Oatfeed is the fibrous hull from around the grain and is removed when the grains are processed for use in human foods such as porridge. Oatfeed contains around 25% fibre so although it comes from a cereal plant, it’s not the grain itself and so is relatively low in starch at approximately 10-12%. It is supplied in a pelleted form and so can be used to dilute other ingredients in lower energy feeds.