Horse Owners and Equestrian Business Managers

In the past year, inadvertent use of manure containing aminopyralid has led to a small number of incidents involving alleged damage to sensitive crops being reported on allotments and in gardens in the UK.

The manure possibly came from farm animals or horses that had eaten pasture or conserved forage from grassland treated with a herbicide containing a small amount of aminopyralid.

Here are some facts about aminopyralid for horse owners and those in charge of equestrian enterprises, such as livery yards, racing stables and riding schools.

What is aminopyralid?

Aminopyralid is the active ingredient in herbicides such as Forefront, Pharaoh, and Banish. These herbicides are among the most effective for controlling and eliminating many deep-rooted perennial weeds found in grassland, including docks, thistles, nettles, and ragwort.

Ragwort control is especially important, as it can be deadly if eaten by horses.

When grassland is sprayed with aminopyralid, it kills the target weeds but does not affect the grass. However, when this grass is eaten by horses either out in the field or as conserved feed such as hay or haylage, a small amount passes out with the resulting manure.

You can test manure for aminopyralid residues (see instructions on right). If you believe you have manure containing aminopyralid, please contact us.

Is aminopyralid harmful to my horse?

No, but you must follow all labelling and safety literature, including:

The Pesticides Safety Directorate (PSD) has determined that, when used correctly, aminopyralid poses no harm to horses or other animals.

If you are spraying paddocks or pastures with herbicides containing aminopyralid, follow the advice on the product label and safety instructions, including:

Keep livestock out of treated areas for at least seven days after spraying.
Where you have sprayed for ragwort, keep animals off treated pasture until the weeds have died and have become unpalatable or have been removed.

How long does it take for aminopyralid to break down?

Micro-organisms in well-aerated soil breaks aminopyralid down over a period of time. If manure that contains aminopyralid is incorporated into soil and turned over frequently, the chance of any adverse effects on sensitive crops subsequently grown in that soil diminishes significantly after six months.

Treated paddocks and grasslands are considered aminopyralid-free after 12 months.

What should I do with affected stable waste?

It is important to think carefully about the disposal of any stable manure that may potentially contain aminopyralid residues.

Affected manure must not be given or sold on to gardeners or allotment holders as it will affect any sensitive crops that they subsequently grow in soil it has been incorporated into.

One safe option is to supply it to a farmer for use on pastureland or other land intended for grass, cereals, or maize, as these crops are not sensitive to aminopyralid.

Affected manures can also be applied to ground that is being re-seeded with a grass mixture.

If you sell your stable muck through a third party you must tell them if you have treated your grassland with an aminopyralid-based herbicide, or if you know that your horse has eaten hay or haylage made from treated pasture.

This will ensure that affected manure does not end up in gardens or allotments.

Where can I get more information?

Link to the following sites for more information about the use and effects of aminopyralid:

Horse and Hound:

http://www.horseandhound.co.uk/horsecare/1370/36547.html

Dow AgroSciences Forefront labels and leaflets:

http://www.dowagro.com/uk/labels/index.htm

Grassland Management, Dow AgroSciences:

http://www.dowagro.com/uk/grass_bites/management/success.htm

Pesticides Safety Directorate:

http://www.pesticides.gov.uk/garden.asp?id=2480

Department for Environment, Food, and Rural Affairs:

http://www.defra.gov.uk/farm/wildlife/weeds/index.htm

Be informed

Ask your hay or forage supplier if their product came from a farm or grassland where herbicide products Forefront, Pharaoh, or Banish were used. If you are aware, you can take the necessary precautions to prevent affected manure from reaching gardens and allotments.

Test manure before using it at home

Thoroughly mix 1 part manure with 1 part multi-purpose compost in a clean bucket. Prepare enough to fill four 5-inch pots.
Fill another four clean pots solely with multi-purpose compost. These will be the untreated comparisons.
Place each of the pots in a separate saucer to prevent water from on pot reaching another.
Water the pots and leave to stand for 24 hours.
Plant each pot with four broad bean seeds.
Observe subsequent growth for four-week period and note any ill effects in the pots containing the manure mix, such as cupped leaves and fernlike growth on new shoots.

These symptoms may indicate aminopyralid residue in the manure. Signs of other kinds of damage will most likely indicate other issues such as damping off or bacteria-infected soil, etc.

Or send a sample to a laboratory...

You can have manure samples analysed for the presence of aminopyralid. The Central Science Laboratory (CSL) will provide this service at approximately 200 per sample. Contact them at era@csl.gov.uk

Follow all safety instructions when spraying grassland

Keep horses and pets safe

Keep pets off sprayed areas until dry.
Do not allow horses to graze on sprayed pasture for at least seven days or until the weeds (especially ragwort) have died and are unpalatable or have been removed.

Minimise the impact of aminopyralid

If you have bought in hay or haylage or have sprayed your paddocks with aminopyralid, the resulting manure should be:

Spread onto pastures
Supplied to farmers for use on grassland or other land intended for grass, cereal crops, or maize
Fully rotovated into soil where sensitive plants such as potatoes, peas, and beans will not be grown

Contact us

If you have further questions, email us at UKhotline@dow.com.