Fiona Watkins, Indpendent Equine Nutritionist, BSc, Pro Dip.
Chennels West, Brook Lane, Albury Heath, Guildford, Surrey. GU5 9DH.
Telephone:- 07919 994634
Email:-
Minimising dust in hay
All hay contains a certain amount of dust. Contaminants include fungal spores, bacteria, pollens, dust mites and other dust fragments. The extent of contamination with fungal spores largely depends on the dry matter at baling. A survey of English hay over the last ten years has reported that over 90 per cent of hay samples had a spore count of over 10,000/g of material. The type of spores present is important with some being more harmful than others.
The thermophillic actinomycetes are most likely to contribute to respiratory disease. Exposure to these harmful contaminants may contribute to respiratory hypersensitivity and infection and even recurrent airway obstruction.
Moulds produce substances called mycotoxins, which when consumed chronically can severely affect a horse’s health. This is particularly relevant for performance horses, where mycotoxicosis can lead to loss of performance, poor appetite, failure to thrive and specific health problems related to the liver and digestive systems.
Steps should be taken to minimise the horse’s intake of mould, spores and mycotoxins to ensure good health and maximum performance. These steps include:-
1. Soaking Hay
This process dramatically reduces airbourne particles by:-
- washing them off the hay and,
- initiating the germination process of the spores.
Any dust particles not washed through will stick to the hay, which at least means they cannot escape into the air, but it does mean that these spores are ingested and it is not known whether the long-term ingestion of dust and fungal spores can have detrimental affects on health.
Prolonged periods of soaking haycan cause significant loss of nutrients.
Research has shown that a 10 minute soak is adequate to reduce the respirable particles numbers by 95% while minimizing nutrient loss and so this is the recommended time for soaking hay.
2. Steaming Hay
Steaming hay is more time-consuming but the advent of commercial hay steamers has made this process considerably easier and has the advantage that it kills the bacteria and fungal spores present and does not cause loss of nutrients from the hay.
3. Vacuuming Hay
In this process, the hay passes through a ‘dust cure’ machine and it is the most effective method of removing contaminants. Having taken in the hay, it combs and vaccums it, delivering loose, clean material. The machine is fully portable but must be connected by a qualified electrian to a 20-amp single-phase electricity supply.
The machine is relatively expensive but would be a valuable item of equipment in a large yard (in fact, all horses and ponies would benefit greatly from the advantages of having 97 per cent of dust removed from their hay). It should take two-and-a-half minutes to process a bale but, in practice, the machine can prove rather more time-consuming.
4. Shaking Hay
Shaking hay thoroughly using a long-handled fork out of doors allows dust fragments to be blown away. A protective mask should be worn or steps taken to ensure that the dust blows away from the handler. This is not a very effective way of reducing your horse’s exposure to moulds and spores.
5. Mycotoxin Binders
Feeding a mycotoxin binder can reduce the impact of mycotoxins. Some of which are derivatives of yeast cell walls, whilst others are clay-like substances. These products bind the mycotoxins in the gut rendering them less harmful.