We were very excited for Chloe Drakely from the University of Derby to use one of our Simply Steam Hay Steamers to carry out her dissertation on Do Horses Have a Preference Over the Way Wet Hay is Prepared? and have taken all of the key information from the study to read below.

Compared to wild horses domesticated horses have a widely reduced diet and restricted grazing times. Over 50 plant types can be consumed in the wild which is limited to just a few for domesticated horses. Naturally foraging and grazing can last 18 hours. It is therefore important owners ensure that forage is highly palatable for the horse. This study looked into horses’ preference on preparation methods of wet hay.

4 horses were offered 3 different types of wet hay simultaneously for a period of 15 minutes. These include wet nets which were dunked in water, soaked nets which were left submerged in water for 1 hour and steamed hay which was steamed in a Simply Steam steamer for 1 hour. 2 horses were tested each day for the duration of the data collection period.

Data was collected in the form of first approached and time spent consuming each type and ran through SPSS in the form of a Chi – Square test and Kruskal-Wallis test. It was found that steamed hay was the most palatable with it being approached first on 87% of occasions and the average time spent eating it over the duration of the study was 30.07. This is over double that of the next closest hay type, wet hay with an average of 11.76. Literature suggests that the smell and taste is sweeter and added moisture makes it easier to chew.

An additional test was carried out on horse 3 as he had abnormal results when compared with the other 3 horses in the study. It is believed this difference in results could be linked to the horse behaviour and temperament.

The main purpose for providing hay that in some way has been made wet is to reduce the respirable dust particles. However, different preparation methods can change nutritional values as well as the mould, bacteria, and dust concentrations.
Wet hays nutritional content is not altered much from its dry matter form as it is not exposed to the water long enough. Wetting hay is mainly used for reducing the amount of airborne repeatable particles that could be inhaled.

Soaked hay is used to reduce nutritional values of hay and airborne respirable partials especially useful in management of equine metabolic syndrome and laminitis (Müller et al., 2015). Soaking for prolong periods of time reduces minerals and one study suggested that after 15 minutes macronutrients had reduced significantly along with water-soluble carbohydrates which will help with respiratory problems (Bochnia et al., 2021). Crude fibre had increased in this time along with acid detergent lignin and acid detergent fibre content. Argo and McGowan (2014) also found increases of between 30% and 35% in acid detergent fibre and up to 74% in neutral detergent fibre with losses up to 5.7% in minerals when soaking hay. A decrease of between 5 and 15% was seen in metabolizable energy. Decreases of up to 35% was seen in prececal digestible amino acid and crude protein fraction content. Before soaking the prececal digestibility was at 56% however after the 15 minutes had reduced up to 49%. These values had limited change after this point (Bochnia et al., 2021). Owens et al., (2019) also found that soluble protein concentration in soaked hay is reduced along with potassium and non-structural carbohydrates compared to previous values in the dry matter. The reduction from soaking of water-soluble carbohydrates leaves the horse to chew on insoluble fibres which are harder to digest and provide less nutrients (Ferguson, 2008). Soaking makes it hard to calculate the horse’s nutritional intake and therefore the correct amount to feed.

Steaming was found to reduce yeast levels. Reductions of up to 99% in airborne respirable particles and the microbial contamination have been seen in tests by Moore-Colyer et al., (2016). Similarly, Claußen et al., (2018) found this content in steamed hay is reduced by 89.92%. He also found that steaming hay can increase water content from 13% to 31%. Water-soluble carbohydrates were reduced by 18.3% and a preservation in protein and mineral content was also observed. Earing et al., (2013) also found that water soluble carbohydrates reduce by 13%, however he adds that ethanol-soluble carbohydrates reduce by 27%. James and Moore-Colyer (2013) state that a 2.3% loss can be seen in water-soluble carbohydrates which is likely due to nutrient leaching from cellular structures experiencing heat induced breakdown, which is beneficial for laminitis ponies.
As steaming can help poor hygienic quality hay without stripping it from necessary nutrients many other methods can be used to slow down the horse’s forage intake so consumption is not too high, but the horse can still graze for long period of time. These methods include creating multiple locations for forage and the use of smaller holed hay nets (Ellis et al., 2015). Whereas for soaked hay other methods can be used to increase consumption time lengths such as grazing muzzles, strip grazing and small hole hay nets (Glunk et al., 2013; Lundqvist and Müller, 2022). Hay nets do allow for small particles including dust to fall out the net however this can then be inhaled by the horse. In the field grazing muzzles are often used so that the amount of grass picked up with each bite is reduced. Strip grazing is where the horse must walk to different feeding and water stations to encourage movement.

Impact on Owners

Soaked hays waste material, mainly liquid, can be classed as an environmental pollutant. This means that it can be hard to dispose of whereas steamed hay has little to no wate product. The department for environment, food, and rural affairs (DEFRA) state that any runoff must be placed into a sealed effluent tank or impermeable lagoon and disposed of by licenced removal company (GOV.UK, 2015). For many owners this can prove difficult to implement and maintain especially in larger livery yards. Besides these removal costs soaking hay can be relatively cheap for owners as all they need is a bucket and water. Steaming hay can be expensive as the initial cost of equipment and then running costs such as water and electricity can be high. It has been suggested by Simply steam that the running cost is between £0.68 and £1.34 per hour.

Results

With the use of SPSS, data on the type of hay net approached first was analysed and presented in a pie chart as seen in figure 2. Average times spent eating each forage type for each individual horse was analysed and recorded in a bar chart as shown in figure 3. A simple boxplot was also created to display the deviation in overall time spent eating each forage type and the mean and average consumption time as shown in figure 4.

4.1 Hay Type Approached First

Figure 2: Figure 2 shows how often each type of hay was approached first.

A Chi – Square test was used to analyse the data collected. There was no significant association between individual horses and the forage they chose first (x2(3) = 2.4, p = 0.494). Although there was no significant association for each horse, overall, 83% of the time steamed hay was the first to be approached. Soaked hay was never approached first.

A Pie Chart to Show How Often Each Hay was Approached First

Wet 17%

Soaked 0%

Steamed 83%

All horses except horse 3 shows a significant preference to steamed hay. Only horse 2 had notable time spent at the soaked hay and horse 4 only consumed the steamed hay.

4.3 Total time spent on each forage type

Figure 4: shows a simple Boxplot of the amounts of hay consumed overall.

A Kruskal-Wallis test was used to analyse the data collected. There was a statistically significant difference between time spent consuming wet hay (M=11.76, SD = 14.06), steamed hay (M=30.07, SD = 13.64) and soaked hay (M = 0.19, SD = 0.27) (H(2)=7.13, p = 0.028). The results show that the horses had a statistically significant preference for steamed hay.

Time Eating Steamed Hay

The aim of the project was to prove that steamed hay is the preferred wet hay preparation method for horses. The results show that horses do have a significant difference in the time that is spent consuming hay for different preparation methods. As the results show that steamed hay had a mean consumption time of 30.07 overall whereas wet, the next most consumed, only had a mean of 11.76 it can be inferred that horses do have a preference to steamed hay over the other preparation methods of soaking and wetting hay. Theses consumption times can be seen in the box plot in figure 6 and raw data in appendix 5. Earings et al., (2013) study also found a preference for steamed hay where 1.38kg more steamed hay was consumed than dry forage over the duration of his study. Literature backs this finding up as Owens (2019) found that horses preferred steamed hay as it was evenly treated, then dry hay and finally soaked hay. Literature suggests that this is due to horses having a preference for sweet tastes and many have suggested a sweetened odour (Merkies and Bogart, 2013). This result has been found in studies with varying sample sizes from 6 to 31 horses and breeds from a variety of breeds including warmbloods, cobs, and standard bred horses (Laat et al., 2022). Merkies and Bogart (2013) also state that knowing this preference for horses helps with increasing the consumption of nutrients. Holzer et al., (2022) along with Mueller et al., (2021) and Redgate et al., (2014) also found that hay with higher crude protein and sugar contents is preferred by the horse. All of these statements are backed up by Berg et al., (2016) who agrees preference is determined by the odour, taste and nutrient content of forage. Sroka et al., (2022) did suggest that out of these preference factors odour has the lowest effect. The texture of steamed hay has also been suggested to positively affect consumption and palpability due to the added moisture and softening effect of the steam (Earing et al., 2013).

CONCLUSION

It is imperative that owners and care givers are able to understand and interpret animals’ specific behaviours to indicate when the horse is stressed and their preferences. Horse welfare should always be the main priority. Along with appropriate management of horses correct feeding practices helps to ensure good mental and physical health. It is important that horses are provided with highly palatable methods of feeding to ensure appropriate nutrition is consumed. It limits negative and oral stereotypical behaviours such as crib biting and helps in the prevention and management of a variety of medical conditions. Including but not limited to Reoccurring airway obstruction, colic, and gastric ulcers.

Soaking hay does reduce the nutritional values more than steaming or wetting hay, but it is less palatable. Therefore, it may be better to feed steamed hay and instead reduce intake times with other methods such as the use of small holed hay nets or placing hay in different locations around the field or stable. This will also provide mental stimulation as horses are natural foragers.

This study allowed for a range of research methods to be utilised to collate information relating to the aim of the study. The hypothesis that steamed hay would be the preferred preparation method was proved during the study. A clear trend in the preference for steamed hay can be seen within the results of this study. With over 3 quarters approaching the steamed hay first and significantly more steamed hay being consumed for the duration of the study.

Future research is needed to identify if this continues with a larger sample size and provide better reliability of results. Also, further research is needed to identify if the order or location of nets effects the horses’ choices.