Pasture management

Regular pasture management ensures your horse’s grazing remains in good nutritional condition; it is also one of the main ways of achieving effective parasite control in your horse. Effective pasture management, along with faecal egg count monitoring and use of a regular deworming programme, should ensure your horse benefits from nutritious grazing and remains free from internal parasites.

Pasture management involves the following:

  • Ensuring your horse’s grazing is in good condition and contains the necessary nutrients required for a balanced diet
  • Maintaining the pasture free from weeds and poisonous plants
  • Ensuring your horse’s grazing remains free from infective eggs and larvae, so reducing infection with internal parasites
  • General maintenance, e.g. fence conditions, safety, constant water supply, etc.

Good pasture management can be achieved by regular removal of faeces and pasture rotation, as well as cutting/topping, fertilising, weed killing and harrowing the pasture.
Removal of faeces has been shown to be a highly effective method. The most effective is to remove and dispose of faeces from the pasture every day which is obviously time consuming. In larger stables mechnical sweepers can used. If you cannot achieve this daily, removing the faeces on a regular basis (at least twice a week) is still effective in reducing the numbers of larvae on the pasture. This method is very effective in removing the eggs of the large and small strongyles. Most of the ascarid eggs will be removed and, although a few will remain as they are very sticky, the number should not cause problems. Regular removal of faeces will remove the tapeworm eggs before the mites can eat many, but removal will not reduce the number of bots.
Pasture rotation can also be an effective way of reducing the number of larvae on the grass. However, larvae and eggs are very resistant and can survive for long periods on pasture (many months and in smaller numbers even a year and far more for ascarid eggs). The pasture should be rested for at least 6 months to successfully reduce the numbers of larvae. Allowing other livestock, such as sheep, cattle and goats, to graze on the pasture can help to break the lifecycles of the equine worms. If you transfer your horses directly onto the fresh rested paddock they may contaminate it with worms. Preferably ask your vet to carry out faecal egg counts on the horses before transfer, then you can worm the horses that have worms 48 hours before they are moved on to the fresh, rested paddock.
Cutting or topping any long, rank areas of pasture as they appear will encourage stronger grass growth and even grazing. It is suggested that sward length should be maintained at a maximum length of 4″.
Fertilising your horse’s grazing ensures minimal weed growth, maximum grass growth and ensures the pasture contains the necessary nutrients required by your horse for a healthy diet. Fertilising should be done in the spring and autumn with a recommended fertiliser. It is advisable to obtain soil samples, which can be analysed to determine what sort of fertiliser your pasture needs to ensure it contains the correct levels of nitrogen, phosphorus and potassium. Soil sampling is recommended every 4-5 years. When fertilising, your horse should be kept off the grazing until the fertiliser has washed into the soil, this is usually for a period of two weeks (less if it rains frequently for a few days following fertilising).
Weed killing can be done by undertaking regular spraying of your horse’s paddock with a suitable weed-killer to remove infestations of weeds such as stinging nettles, and probably most importantly, any poisonous plants such as ragwort. Spraying is not always possible, in which case manual removal of poisonous plants should be done on a regular basis – ragwort is of particular importance as ragwort poisoning is life-threatening; ragwort is also classified as injurious by the 1959 Weed Act, and it is an offence to allow it to spread. Over-hanging trees should also be monitored to ensure they are not providing unsuitable snacks for your horse!
Harrowing your horse’s paddock aerates the soil by removing dead grass and moss from the pasture to allow new grass growth during the spring and autumn. Harrowing can also be useful during the summer months to break up piles of faeces allowing them to dry out, exposing any parasite larvae to the elements and to predators. Harrowing should only be done when the grass is short and the weather is dry so the larvae are exposed to sun and die from desiccation, otherwise it is counter-productive for effective worm control. Horses should not graze on the paddock for several weeks after harrowing.

Other important steps towards effective pasture management include:

  • General maintenance of the field and its surroundings, ensure:
    • All fence lines are in good condition and are ‘horsey’ friendly, so as to avoid your horse escaping or injuring itself on damaged or inappropriate fencing, e.g. barbed wire
    • Your horse has access to a constant supply of fresh water
    • Your horse has access to shelter, either natural, e.g. from bushes/trees, or man-made, e.g. a field shelter
    • There are no holes in the ground, e.g. rabbit holes, that your horse could put its foot in
  • Keeping the number of horses per acre (stocking density) to a minimum reduces the amount of damage to the grazing and also reduces the amount of faecal contamination. As a result, this reduces the numbers of larvae on the pasture. As a general rule one horse per acre is recommended.
  • Avoid your horse’s paddock getting poached (excessively muddy) during the wintertime. A poached paddock can cause mud fever and it will also reduce the quality and density of the grass, leading to increased weed growth.
  • It is also important to prevent your horse’s paddock from being over-grazed; this can also lead to a reduction in the quality and density of the grass, leading to increased weed growth.