Equine Feed Storage: Moisture, Pests and Contamination Control

Feed storage is part of feed safety. A sound ration can be compromised after delivery if it is exposed to damp, condensation, rodents, birds, insects, dirty equipment, chemicals or residues from an earlier product. In an equestrian setting, the consequences may include loss of nutritional value, rancidity, mould growth, contamination with faeces or urine, accidental access to the wrong feed and avoidable respiratory exposure to dust and spores.

The central principle is straightforward: keep feed dry, cool, clean, identifiable and inaccessible to pests, while using it quickly enough that deterioration does not outpace the storage system. This applies to compound feeds, straights, cereals, balancers, supplements, treats, soaked-feed ingredients, forage and bedding stored in the same building.

Great Britain’s feed-hygiene framework places emphasis on suitable storage, cleanliness, prevention of contamination, pest control, identification and traceability. The legal detail varies according to whether a business is storing feed for its own horses, feeding animals intended for the food chain, manufacturing or marketing feed, or operating as a registered feed business. The practical controls described here are therefore useful across the sector, but commercial operators should establish which registration, record-keeping and hazard-control duties apply to their activity.

Why moisture is the primary storage hazard

Moisture does not merely make feed look untidy. It changes the environment in which moulds, bacteria, insects and mites can survive or multiply. Water may enter as rain through a defective roof, rise from a concrete floor, condense on a cold bin or wall, leak from a water pipe, or be introduced when damp scoops, buckets or partially washed containers are returned to storage.

Summer protection needs to balance insect coverage with airflow and freedom of movement. Readers comparing mesh, neck coverage and fit can see practical examples in the fly rug range at JSM Equestrian Supplies.

Condensation is particularly easy to miss. A feed room may appear dry while warm, humid air deposits water on the inside of a metal lid or silo wall. Temperature fluctuations can also produce localised wet spots in bulk stores. These areas may cake, heat, smell sour or support mould even when the majority of the batch remains apparently normal.

Dry feed is not sterile. Bacterial spores, fungal spores and insect eggs may already be present at low levels. Storage conditions determine whether they remain insignificant or become a practical hazard. Defra and the Animal and Plant Health Agency identify moisture, dust and feed residues as potential reservoirs for bacteria and as factors that attract pests. The GB code of practice for Salmonella control notes that Salmonella can survive dry and freezing conditions, while growth is favoured when warmth, moisture and nutrients are available.

Moisture control should therefore begin before feed enters the store:

• Repair roof, gutter, wall and floor defects before accepting a new consignment.
• Keep feed away from doors that admit wind-driven rain and from walls known to sweat.
• Separate feed from water tanks, wash-down areas, taps and pipes.
• Use pallets, stillages or other raised supports rather than placing bags directly on a concrete floor.
• Allow air circulation around stored bags and avoid compressing packaging against damp walls.
• Do not return wet scoops, measuring cups or buckets to a dry-feed bin.
• Investigate caking, heat, unusual odour, condensation or changes in texture rather than simply mixing affected material into fresh feed.

Mould, mycotoxins and the limits of visual inspection

Mould is a group of fungi rather than a single contaminant. Some moulds primarily reduce palatability and increase dust; others can produce mycotoxins, which are chemical compounds formed by particular fungi under suitable conditions. A product can therefore be unsafe or unsuitable without having a dramatic visible bloom, and visible mould does not identify which toxin, if any, is present.

AHDB guidance describes moisture and temperature as important determinants of mycotoxin production during grain storage. It also highlights the importance of cleaning old grain and dust from stores and machinery because storage fungi can persist between consignments. For equine premises, this makes residue removal and stock rotation more than housekeeping preferences.

Do not assume that a dry-looking bag is necessarily sound. Fine dust, webbing, insects, caking, heating, sour or musty odours, oily rancidity, discolouration and an unusual reluctance of horses to eat a feed are warning signs. Conversely, the absence of these signs is not proof that a feed is free from mycotoxins. If contamination is suspected, isolate the batch, retain its label and batch information, and seek advice from the feed supplier or an appropriately qualified feed or veterinary professional. Do not attempt to make a suspect feed acceptable by adding a supplement, diluting it with clean feed or removing only the visibly affected portion.

Wetting, soaking or steaming may alter dust exposure or the physical characteristics of some feeds, but these processes should not be treated as a universal method of removing mycotoxins. A Wisconsin Extension review specifically warns that reducing the physical dust problem does not necessarily reduce mycotoxins in mouldy forage.

Choosing a storage location

A feed store should be a dedicated, manageable space rather than a corner of a general-purpose shed. The best location is weatherproof, well drained, ventilated without being exposed to driving rain, and sufficiently secure that horses, dogs, cats, wildlife and unauthorised people cannot gain access.

Feed should be kept away from:

• fuels, lubricants, pesticides, herbicides, disinfectants and other chemicals;
• veterinary medicines and supplements not intended for the same animals;
• muck, manure, used bedding and waste bins;
• dirty tack, boots and yard equipment;
• open drains, leaking water systems and wash-down points;
• hay or bedding that is dusty, damp or visibly mouldy;
• vehicle exhaust, workshop dust and areas where welding, grinding or painting takes place.

Where space is limited, physical separation is still worthwhile. Feed can be placed on one side of a clean partition, with chemicals and equipment in a separate locked cupboard or room. The objective is to prevent a leaking container, dropped bottle or contaminated tool from making contact with feed or feeding equipment.

Good layout also reduces handling errors. Every product should be identifiable from its packaging or a durable label. Bags should not be transferred into unlabelled bins, and a bin should not retain a label for a previous product after its contents have changed. On a working yard, labels should state the product, animal or group, date opened where useful, and any relevant feeding or medication status.

Storage containers: materials, design and performance

Original bags

Original bags preserve the manufacturer’s label, batch number, best-before information and feeding instructions. They are useful for traceability and may offer an adequate short-term barrier when kept dry and closed. Their limitations are vulnerability to rodents, puncture damage, moisture wicking from floors and deterioration after repeated opening. Sacks should not be left leaning against damp walls or stored where forks, nails or sharp pallet edges can tear them.

Plastic bins

Food-grade plastic bins with close-fitting lids are convenient for small and medium quantities. They are generally easy to wash, light enough to move and resistant to surface corrosion. Their performance depends on construction: thin plastic, poorly fitting lids and small gaps around hinges may not exclude determined rodents or insects. Some plastics become brittle in ultraviolet light or cold conditions, while others retain odours from oils or supplements.

A plastic bin should be large enough to permit cleaning but not so large that old feed remains inaccessible at the bottom. It should stand on a stable base, be protected from impact and be checked for cracks, chew marks and lid distortion. A sealed lid is useful, but a completely airtight container is not a substitute for putting dry feed into it. Sealing damp feed can trap moisture and accelerate deterioration.

Metal bins and drums

Robust galvanised or painted steel containers can provide strong rodent resistance and good physical protection. They are less vulnerable to chewing than many plastics, but they may dent, rust at seams or create condensation on internal surfaces when temperatures fluctuate. Any coating or lining must be suitable for contact with feed, and sharp edges must not be exposed.

Metal containers are often heavy and awkward to empty. A design with a smooth interior, accessible lid and no inaccessible ledges is preferable. Where a bin is used for different feeds over time, it must be completely emptied and cleaned between products.

Bulk bins and silos

Bulk storage is appropriate for larger yards and commercial operations when the bin has been correctly specified, installed and maintained. Important factors include weatherproofing, sealing, safe access for inspection, discharge reliability, resistance to bridging and the ability to remove residues from joints, outlets and dead spots.

Bulk systems can reduce packaging waste and handling, but they can also conceal deterioration. Temperature monitoring, inspection ports, intake controls and documented cleaning become more important as volume increases. Defra guidance advises emptying and cleaning storage units before new consignments where possible, or at least before a refill at an appropriate planned interval, with particular attention to joints and grooves where old material can lodge.

Pest control: exclusion before extermination

Rodents, birds, insects and wildlife present two related problems. They consume or damage feed, and they can introduce faeces, urine, feathers, hair, nesting material and microorganisms. Rodent activity may also cause secondary damage by chewing bags, electrical cables and insulation.

The most reliable pest-control system is a hierarchy:

1. Remove food and water sources. Clean spills immediately, empty feed dust from corners and repair leaking taps or pipes.
2. Exclude access. Close doors, repair holes, fit suitable door seals and protect vents without compromising safe ventilation.
3. Protect feed. Use containers and lids that cannot be readily chewed, tipped or opened by animals.
4. Monitor. Look for droppings, gnaw marks, tracks, nesting material, damaged packaging and unexplained losses.
5. Control an established problem. Use a competent pest-control provider where necessary and manage traps or rodenticides so that horses, dogs, cats, wildlife and children cannot access them.

Poison should never be placed loosely in a feed room or where a dead rodent could fall into a bin. The British Horse Society’s welfare code advises that feed should be stored in vermin-proof containers, while feed containers and utensils should be kept clean to discourage rodents. Where a dead pest is found in or beside feed, quarantine the affected material rather than removing the animal and continuing to use the batch.

Insect pests can arrive in grain or manufactured feed, particularly where stock is held for long periods. Signs include live insects, larvae, webbing, pinholes, dust trails and clumping. Do not apply an insecticide directly to feed unless the product is specifically authorised and the treatment is being carried out under appropriate professional and legal controls. In most equine stores, better stock rotation, cleaning and removal of infested material are safer first-line controls.

Hay, haylage and forage storage

Forage storage has different requirements from bagged concentrate, but the same principles apply: exclude rain, ground moisture, animals and contamination while allowing appropriate ventilation.

Hay should be stored under a sound roof, away from leaks and raised from the ground on pallets, rails or another system that permits air movement beneath the bales. The University of Minnesota recommends a waterproof, animal-proof storage site and warns that bales stored directly on the ground can absorb moisture. Rodent holes and wildlife access should be addressed because animals can foul hay, chew twine and introduce contamination.

Freshly baled hay deserves particular attention. If it was baled too wet, microbial activity can generate heat and mould during storage. A stack should be inspected for hot spots, smoke, musty odour and changes in bale condition, especially during the early storage period. A probe or temperature-monitoring procedure may be appropriate for larger quantities, but any person inspecting a stack must consider the risks of collapse, poor air quality and restricted access.

Haylage packaging should be checked for punctures, loose seals and rodent damage. A damaged bale is not automatically safe because the damaged area appears small: air and contaminants may have entered beyond the visible hole. Store wrapped bales where further damage is unlikely and follow the producer’s guidance for use after opening.

Do not store mouldy forage beside clean forage. Dust and spores can migrate during handling, and the affected material may also attract pests. The GB welfare code states that conserved forage should be clean, fresh-smelling and visibly free from mould and dust; contaminated, mouldy or stale feed and forage should not be fed.

Cleaning and sanitation

Cleaning is most effective when it removes the source of contamination rather than simply spreading dust around. Dry removal by industrial vacuum is generally preferable for dry residues because it minimises the introduction of water and limits aerosolised dust compared with sweeping or compressed air.

A practical cleaning sequence is:

1. Remove all feed, packaging and movable equipment from the area being cleaned.
2. Quarantine damaged or suspect material rather than sweeping it into a drain or outdoor area.
3. Vacuum ledges, corners, joints, pallet spaces, bin outlets and overhead surfaces.
4. Wash only where necessary, using a product suitable for surfaces that contact feed and following its label instructions.
5. Rinse where required by the cleaning-product instructions.
6. Dry the surface and equipment completely before returning feed.
7. Inspect for cracks, leaks, pest entry points and residues before restocking.

Wet cleaning can create a new hazard if a bin is refilled while damp. Defra advises that storage equipment should be dried before fresh feed is introduced. Disinfectants are not a replacement for physical removal of feed residues, and residues of detergents or disinfectants should be minimised.

Scoops, buckets, feed scales and mixing tools need their own cleaning schedule. A scoop used for a medicated feed, mineral product or supplement should not be assumed suitable for unrestricted use with another ration. Dedicated colour-coded equipment is a simple control on larger yards.

Stock rotation, traceability and purchasing

Buying more feed than can be used in a reasonable period increases exposure to humidity, pests and loss of freshness. The appropriate holding period depends on the product, packaging, storage temperature, oil content, moisture content and manufacturer’s instructions. Feed containing added oils or other oxidation-sensitive ingredients may have a shorter practical life after opening than a dry, low-fat pelleted product.

Use a first-in, first-out system, while keeping damaged or opened bags under closer observation. Record the delivery date, product, batch or lot number and quantity where practical. Keep the label until the bag is empty. This is especially important when several horses receive similar-looking products or when a supplier issues a quality notice.

Do not top up a part-used bin with a new bag without first checking and cleaning the old contents. Mixing old and new feed makes it difficult to identify a deteriorating portion and extends the effective age of the older material. A bin should be emptied, residue removed and inspected before it is refilled.

Deliveries should be checked on arrival for wet packaging, torn bags, pest damage, unusual odour, caking, incorrect product or a compromised seal. Photographing damaged consignments and retaining delivery paperwork can help resolve supplier claims and support traceability.

Contamination control in daily yard practice

Many failures occur during feeding rather than in the store itself. Keep feed preparation surfaces clean, wash hands after handling chemicals or waste, and do not place feed buckets on dirty floors. Feed should be measured with equipment that is clean and dry. Pre-prepared feeds containing water, chopped produce or other perishable ingredients should be made in quantities appropriate for prompt use, not stored indefinitely in a warm feed room.

Prevent cross-contamination between horses and products. Label individual tubs clearly, especially where horses receive different supplements, restricted diets or medication. Store medicated and non-medicated feeds separately, and control access to both. Never leave an open bucket of feed where a horse can reach it: accidental overconsumption is a management and safety risk independent of microbial contamination.

Spilled feed should be removed promptly. A small spill is still an attractant for rodents and birds, and repeated small spills can support a persistent pest population. Yard staff should know what to do with feed that has contacted manure, bedding, mud, chemicals, rainwater or a pest.

Inspection checklist

Common misconceptions

“A sealed bin makes any feed safe.”

No. A sealed bin protects against some external contamination, but it can also trap moisture, preserve an existing infestation and conceal deterioration. Feed must be dry and the container must be clean before filling.

“If the horse eats it willingly, it is acceptable.”

Palatability is not a safety test. Horses may consume feed that is contaminated, nutritionally inappropriate or damaged by storage.

“Removing the mouldy layer is enough.”

Contamination may extend beyond what is visible, and mycotoxins are not reliably identified or removed by picking out discoloured material. Suspect feed should be isolated rather than salvaged by appearance.

“Plastic is automatically rodent-proof.”

Some heavy-duty containers resist rodents well; thin or damaged plastic may not. Lid design, hinges, gaps and the surrounding building matter as much as the nominal material.

“More ventilation is always better.”

Ventilation helps reduce condensation, but uncontrolled openings can admit wind-driven rain, birds and pests. The target is a dry, stable environment with managed airflow, not an exposed store.

Quality indicators for storage equipment

When selecting a bin, cabinet, silo or feed-room system, assess the complete product rather than relying on a marketing term such as “airtight” or “animal-proof”. Useful questions include:

• Is the material suitable for contact with dry feed and resistant to the intended environment?
• Can the container be fully emptied, inspected and cleaned without specialist access?
• Does the lid remain secure but practical for frequent use?
• Are there ledges, seams or outlets where residues can accumulate?
• Can the unit be raised from damp floors and safely moved when full?
• Will the construction withstand rodents, impact, ultraviolet exposure and temperature changes?
• Can products be labelled clearly and stock rotated without confusion?
• Are inspection, maintenance and cleaning instructions available?

For commercial yards, the best system is usually the one that staff can use consistently. A technically excellent bin that is too heavy to clean, too small for the delivery pattern or difficult to label may provide poorer control than a simpler system that supports reliable daily practice.

Conclusion

Effective equine feed storage is a chain of controls. The building must prevent water entry; containers must protect feed without trapping damp; pest management must begin with exclusion and sanitation; cleaning must remove residues and end with thorough drying; and stock systems must preserve identity, freshness and traceability.

For most yards, the highest-value improvements are practical rather than elaborate: repair leaks, raise bags from the floor, use robust lidded containers, remove spills immediately, rotate stock, clean bins between products, separate chemicals and medication, inspect deliveries and quarantine anything with unexplained changes. These measures protect both feed quality and the wider hygiene of the equestrian premises.

Sources and further reading

• Department for Environment, Food and Rural Affairs and Animal and Plant Health Agency: Reduce disease risk from animal feed storage units
• GOV.UK: Animal feed legislation
• GOV.UK: Code of practice for the control of Salmonella in animal feed in Great Britain
• AHDB: Mycotoxin contamination: assessment of risk in livestock systems
• AHDB: Grain sampling and monitoring during storage
• AHDB: How the grain store environment affects pest, fungi, insects and mites levels
• GOV.UK: Code of practice for the welfare of horses, ponies, donkeys and their hybrids
• The British Horse Society: Knowing Your Horse – feeding and feed-room hygiene material
• University of Minnesota Extension: Selecting and storing horse hay
• University of Wisconsin Extension: Moldy hay for horses

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