Advice for livestock farmers affected by flooding

Rapidly rising water levels can cut off access to livestock and mean they can’t get to safe lying areas or food. If fields are prone to flooding then, where possible, move livestock ahead of time to fields with suitable drainage and an area where animals can stand out of the mud or damp. Take extra care if livestock are usually kept near a river.

Provide clean water and plenty of food. Outwintering in wet and windy conditions can increase a cow’s energy requirement by up to 15%.

Feed spoilage

It is important to assess your feed for spoilage as it could be contaminated which can cause health problems through chemical toxicity or infections.

Watch our webinar recording to find out how to assess the nutritional quality of flooded silage clamps/bales and explore the options available for standing maize. 

Things to consider

  • Soil/dung contamination – soil may contain clostridia spores; and sewage and effluent contamination may lead to gut diseases such as Salmonella
  • Feed consumption and quality - poor energy and nutrient intake and low dry matter intake may lead to poor rumen function, acidosis and ketosis
  • Bales that have been standing in water may have their feed quality reduced and could be contaminated by water working its way between the layers of film on the bales
  • Introducing new feed - hungry animals will try to eat as much as possible. Changing from mainly pasture to high carbohydrate supplements like cereals, can cause rapid changes in rumen fermentation and there is a risk of developing acidosis, sometimes called grain overload, which can kill livestock


  • Closely inspect bales for separation of the plastic layers and small holes. Assess these bales now so you can plan to source extra feed if necessary
  • Provide clean water and energy feeds to prevent ketosis
  • Introduce new feeds slowly. If stock are/were on pasture, introduce with hay or grass silage first and then gradually add other feeds

Assessing feed stocks

Use our Feed and Forage calculator to understand whether you have a deficit based on current livestock numbers and feed supply and to inform your decisions about stock sales or purchasing of extra feed. The calculator can be used for baled and clamp silage.

Or, you can quickly work out the total dry matter available (t) using this calculation: (number of bales x bale weight (t) x DM%) ÷ 100.

As a guide:

5ft wide round bales = 0.63 t FW

6ft x 4ft rectangular bale = 0.35 t FW


A B C Tonnes (DM)
Silage type No. of bales Bale weight (t) DM% AxBxC/100
E.g. second cut grass silage 400 0.63 30 76

To work out the amount of silage in your clamp, you need to know the volume of clamped material (length x width x height) and the density of the silage. 

Our feed and forage calculator can estimate density for you. 

If you'd prefer to calculate intakes by hand, as a rule of thumb, dry matter intake (DMI) is 2–2.5% of bodyweight. To calculate silage intakes of dairy cattle, see page 21 of our forage first guide








Type of stock


Average liveweight (kg)


Daily requirements (kg)


Feeding period (days)

Total tonnes (DM)









Suckler cows







Growing cattle







Total DM to be eaten (tonnes)


Safety margin – allow for losses (5‒10%)


Total tonnes of DM required


Water contamination

Flood water could contaminate livestock water supplies. The risk will depend on your source of supply and distribution network.

Provide your stock with a fresh trough of clean water or empty and clean existing troughs to discourage stock drinking from flood water

  • It may be necessary to test microbiological quality of water at the point of supply for contamination; view our guidance on taking samples for testing
  • Identify the source of the issue; is it on the public or private water supply system?
  • Find out if the issue is localised; is it just your farm or the wider area? 
  • Let your water wholesaler and retailer know how you are affected 
  • Reduce your non-essential water usage and prioritise use for essential activities 
  • Be prepared to describe your daily water requirements; use the Dairy Water Audit to help
  • Install sufficient, clean storage facilities to receive alternative water supplies, such as those delivered by tanker 
  • Depending how long your supply is interrupted, you may need to consider alternative options from specialist companies such as Water Direct and Wincanton

Manure and slurry

Excess water can cause leaching and runoff from livestock manures.

Manure heaps should not be sited within 10 m of watercourses nor within 50 m of boreholes

High rainfall over autumn and winter months can result in higher volumes than normal in slurry stores. This can pose problems later on, especially in NVZs when slurry has to be spread to prevent stores from over-topping.

The Environment Agency has provided advice for farmers facing difficulties with slurry storage which covers advice on temporary storage, reducing slurry volume and what to do if you need to spread to land.

Contact the Environment Agency on 03708 506 506,or out of hours or in the event of an emergency on 0800 80 70 60, if:


Damp conditions in housing can increase the risk of several conditions because it favours the survival of bacteria and viruses. Damp conditions are also stressful for animals, as they will have to burn additional energy to keep warm.

Things to consider:

  • More frequent scraping out and bedding down may be necessary, particularly in sheds where stocking densities are higher than usual
  • If you are forced to overstock sheds, are there ways to split animals into smaller groups according to size and age?
  • Avoid major changes to the ration until housing conditions are back to normal to keep stress levels as low as possible
  • Ventilation – fresh air is vital even in damp conditions to reduce numbers of circulating bacteria and viruses. However, make sure there are no draughts at animal level
  • Clean, dry, deep bedding will help stressed animals to stabilise body temperature more quickly
  • Consider alternative bedding if straw is in short supply, check our Bedding materials directory for information

Ten top tips to reduce the impact of wetter winters on outdoor pig paddocks

Animal health

Standing in water and deep mud can predispose animals to, and aggravate, infections and diseases, such as foot rot.

The youngest, oldest and pregnant animals, and those kept in high stocking densities, will be most prone to stress and health issues. Discuss the conditions with your vet, who may be able to help to develop a control plan.

View the APHA's report for more in-depth technical information on the medium and long-term effects of flooding

Calving and lambing

The stress of flooding means cows and ewes are more likely to give birth early. Extra checks may be needed as animals may give birth without showing normal signs, e.g. not bagging up. Make sure newborn calves receive at least three litres of colostrum and newborn lambs receive 200 ml of colostrum within two hours of birth.

Explore further resources on colostrum management

Metabolic diseases

Stress and poor access to feed during flooding will increase the risk of metabolic diseases, such as grass tetany, milk fever and ketosis. Look at cows regularly and check for abnormal behaviour that could be a sign of metabolic disorders. 

Try to supplement dairy cows after calving with calcium and magnesium. This can be mixed in with feed and fed in-shed, or mixed with molasses and poured onto bales.


Livestock that have been standing in deep flood water for prolonged periods in cold conditions without access to food may be at risk of hypothermia.

Move livestock to dry sheltered areas with access to feed and clean water as soon as practical, weak animals may benefit from covers.

Transport stress

You may need to transport stock to grazing or housing away from your holding during flooding.

Transporting stock and mixing with other livestock is very stressful from a physical and social point of view. Good feeding, watering and magnesium levels help.

You could provide calcium and an energy drench to freshly calved cows before and after travelling.

The after effects of long-distance transport are detectable for up to two weeks.


Damp bedding can harbour bacteria, which can increase the risk of mastitis.

Infections can enter the udder through the teat canal at any time during lactation or during the dry period. There will be an increased risk of mastitis from environmental bacteria, e.g. E.coli or Strep uberis if animals are cold, wet and dirty.

When lambs and calves suckle from their mothers, the teat end is open and can stay dilated for up to two hours.

  • Provide extra bedding: a clean, dry environment is essential to reduce the risk of bacteria entering through the teat canal
  • Wash hands frequently and keep clothing clean: infections can spread between animals through contaminated hands or clothing
  • When drawing milk from the udder to check for milk supply, collect in a container rather than squirting onto bedding

In wet or muddy conditions, there are four key steps at milking: 

  1. Wash and dry all teats before milking – use a pre-milking teat disinfectant and give it enough time to act. On wet or muddy days, wash and dry every teat with one paper towel per cow
  2. Strip cows every day to detect clinical mastitis cases – treat promptly and isolate
  3. Make sure post-milking teat disinfectant covers 100% of teat skin on every teat of every cow
  4. Teat canals remain open for 1–2 hours after milking – set up feeding and other routines so cows don’t lie down soon after milking; this will help teats to remain clean after milking

Learn more about managing mastitis

Learn more about Mastitis Control Plans

Find out more about mastitis in sheep


High stocking rates, damp housing and poor air quality can increase the risk of respiratory disease. Continue to provide fresh air and freedom from draughts.

Learn how how to recognise, test and treat bovine respiratory disease (BRD)

Youngstock housing: legislation and market requirements


The hoof-horn and interdigital skin can soften in wet, muddy conditions. This can lead to footrot in sheep and digital dermatitis and ‘foul of the foot’ in cattle.

Remain calm and patient when handling livestock.

Extra walking in wet conditions will increase lameness cases. Animals will place their feet carefully if given time to walk at their own pace, which will reduce wear and injuries to softened hooves.

Both cattle and sheep may be more prone to puncture wounds, white line disease (WLD) and abscesses in wet conditions.

Use our lesion recognition and trouble shooter guide to identify conditions in cattle.

Download our lesion recognition and trouble shooter guide

For more information on lameness in sheep, see our guide on Reducing lameness for Better Returns and the resources available at #HealthyFeetHappySheep.

Consult your vet for a treatment and control plan.

Cow tracks are likely to be damaged and repair may take some time – look at options for preventive maintenance if risk of flooding is high.

Cow tracks: learn how to design and build an effective cow track


Wet, muddy fields provide an ideal habitat for the mud snail involved in the maintenance of the life cycle of liver fluke.

The survival of other parasites may be enhanced in wet conditions and lead to problems in the next grazing season.

Additional stress may increase the impact of existing parasite burdens or trigger more severe clinical signs, e.g. Type 2 Ostertagiasis.

For more information on parasite control in cattle, visit the Control Of Worms Sustainably (COWS) website, and for sheep, visit the Sustainable Control of Parasites in Sheep (SCOPS) website.

Download a copy of our liver fluke control in grazing livestock guide

Once floods have receded:

  • Check bales that have been moved by the floods for holes in the wrap; even very small holes will have taken in water
  • Keep a tally of the number of damaged bales and use the feed and forage calculator to calculate your feed requirements 
  • If you have to feed damaged bales to your livestock, do some quick checks to assess the damage to the nutritional quality – watch this webinar about assessing flooded forages to find out how
  • It is likely there will be changes in the flooded soil’s nutritional status, due to leaching and soils being removed or deposited. This may change its texture, pH and the amount of organic matter present. Soil tests may be needed in the spring
  • It is likely that weeds will take advantage of new grass leys caused by flooding in the year of the flood and in subsequent years. Be prepared to take action in the spring to reduce negative impact
  • Check your pastures and streams for potentially poisonous plants or other material, e.g. the roots of water dropwort, which may be exposed after heavy water flow or rainfall and may be toxic to grazing animals
  • Pastures contaminated with silt/sewage will have reduced palatability and intakes may be lower
  • Check the water supply for damage and contamination with silt; drain and clean out contaminated water troughs
  • You may wish to consider long-term planning for extreme weather; for tips and advice, watch our webinar recording

Support for farmers

There are numerous resources you can access and charities that you can lean on when faced with challenges.

Support for farmers: guides, resources and useful contacts

Forage Aid: emergency animal feed and bedding

Webinar: How to assess flooded forages and standing maize