The darker, colder months bring a range of issues for outdoor layer flock.The highest-profile of these is the risk of avian influenza, brought in by migratory birds from Asia and eastern Europe.
Wet, muddy conditions also increase levels of mycoplasma and E coli infections, while worm burdens are an issue – particularly if milder conditions persist.
As naturally available food becomes increasingly scarce, vermin are more likely to target feed bins, bringing with them the risk of salmonella. And as the nights draw in, hungry predators represent an even bigger threat.
Beyond this, there are bouts of severe weather that compromise welfare directly and indirectly by jeopardising feed deliveries, power and water supplies.
It all adds up to a need for flock-keepers to stay alert, says poultry vet Ian Jones of Hafren Veterinary Group in Powys.
He offers some guidance on the precautions that can help limit the impact of seasonal threats.
Avian influenza checklist
- Keep the area clean and tidy, controlling rats and mice and regularly disinfecting hard surfaces
- Clean footwear before and after visits
- Place feed and water in fully enclosed areas that are protected from wild birds, and remove spilt feed regularly
- Fence around outdoor areas where birds are allowed and limit their access to ponds or areas visited by wild waterfowl
- Avoid keeping ducks and geese with other poultry species
The main risk period for avian influenza is between November and March.
Vigilance is paramount during this period and any suspicion of disease, such as mortality in the flock or dead wild birds, should be reported to your vet.
Birds on the range are at risk from contact with any wild birds and their faeces which harbours the disease.
But migratory waterfowl such as ducks and geese, along with the native species that mix with them, are a particular threat.
It means wild birds must at the very least be chased away, but preferably deterred from coming near the range at all.
Any feed spillages around the sheds must be thoroughly cleaned up. Ponds and watercourses should be drained or fenced and covered to deter birds from landing.
Signs of avian influenza
There are two types of avian influenza: low pathogenic (LPAI) and high pathogenic (HPAI). The latter is the more severe type and is often fatal in birds. Its main clinical signs in birds are:
- Swollen head
- Blue discolouration of neck and throat
- Loss of appetite
- Respiratory distress such as gaping beak, coughing, sneezing, gurgling, rattling
- Fewer eggs laid
- Increased mortality
Flocks that are near larger bodies of water are at the greatest risk and may opt to house birds as a precaution.
However, this is a significant step and may compromise the free-range status of the eggs, unless there is a mandatory housing order in place, sanctioned by the Animal and Plant Health Agency (Apha).
With all this in mind, here are the nine key areas to focus on:
1. Be prepared
Contingency plans are usually geared towards the threat of avian influenza, and all farms should have an action plan.
However, there are a number of scenarios where being prepared will be an advantage in the winter.
For example, having a list of key contacts for a range of emergencies will help when time is of the essence.
Phone numbers for vets and local Apha offices should be to hand, as well as those for electricians and other maintenance experts if supplies are disrupted by bad weather.
2. Tackle standing water
Aside from the larger bodies of water, winter on the range sees the emergence of puddles and mud patches which can harbour bacteria such as E coli and mycoplasmas, causing high rates of mortality.
Hens would often rather drink from puddles, so consumption through nipples and drinkers can fall by 20%.
This represents a significant disease risk as muddy puddles can be contaminated with bacteria, and they attract wild birds, creating a concentrated point of contact with the flock.
Muddy patches will also help to spread the soil-borne bacteria, especially when hens take it into the house on feathers and feet.
Parasitic worms are an additional and increased threat when wet weather strikes; and the situation is worse still when raised soil moisture is combined with unseasonably mild conditions.
Standing water must be tackled. First, puddles should be drained and filled with gravel to prevent them from refilling. Second, wet areas should be mapped and recorded so that drainage work in the drier months can target trouble spots.
Mud and water around the house should not be tolerated because, once taken into the shed, the additional moisture can ruin scratch areas and compromise litter, giving rise to higher humidity and ammonia rates that threaten respiratory health.
If this is occurring, the drained area around the curtilage needs to be widened with existing stone areas, concrete walkways or verandas extended, so birds can shed the mud before they go through the popholes.
3. Protect popholes
Popholes should also be protected ahead of the winter to prevent rain and draughts entering the house. In Scandinavian countries, popholes are sheltered by an extended, covered area.
Known as a “winter garden”, this creates a transitional area between the house and range to keep out the elements and allows birds to shed mud and moisture.
Providing cover can help deter predators and vermin by limiting the amount of light visible in darker afternoons and evening before the house is shut up. Foxes and rats will be attracted by the glow, so it is worth minimising the effect, if possible with a covered area.
4. Manage grass
Preventing salmonella infection is crucial for egg producers and forms a key part of the Lion Code assurance scheme. This means deterring the vermin that carry the disease is critical.
Rodents and other pests use long grass as cover to move around and gain access to feed stores or housing.
It’s a good idea to top ranges but only while land is still firm enough to travel on without causing ruts that lead to poaching and later standing water.
Ideally, grass should be kept short at about 7.5-10cm (3-4in) to discourage rodent movements. Swards could be left shorter still, but it is worth noting that the grass will hold moisture and reduce the likelihood of run-off and standing water.
Bare patches should be reseeded but only at turnaround. If reseeding is carried out with the birds on the range, it could encourage wild birds to feed, bringing with them the threat of disease.
5. Rotate paddocks
When grass growth declines and wind and rain means birds stay close to the house, ranges can become worn.
RSPCA and other assurance schemes stipulate that the range must be in good condition. It is best, then, to rotate flocks through a paddock system.
As a rule of thumb, a 6,000-bird flock should have access to four paddocks and should be rotated monthly to control parasitic worms, to limit disease build-up and help the grass to recover.
However, the closed paddocks should be checked daily to ensure the birds aren’t getting stuck on the wrong side of fencing.
6. Check drainage
Drainage work is best carried out in the drier months. But ditches and outlets should be rechecked ahead of winter to ensure there are no blockages that might lead to backing up and flooding.
Any areas that are vulnerable to flooding or run-off in heavy rain should not be used to store muck or litter at depopulation.
The potential to cause pollution and spread disease-harbouring muck across the range for the incoming flock is too great a risk.
Other preparations include checking the maintenance of water supplies and ensuring any exposed pipes on the range are buried deep enough not to freeze and are suitably insulated.
There should always be a contingency for water provision in freezing conditions, including keeping bowsers topped up with enough supply to last at least 24 hours.
Birds will not survive beyond a day without water, so this should be a minimum.
Outdoor shelter is another critical provision that should be checked. Birds will shelter in high winds and heavy rain, so there should be adequate provision of trees and structures to allow them to find cover.
Shelters should be robust and well maintained to ensure they don’t flap and bang in high winds, which will frighten birds back into the open and cause stress.
Raised stress levels due to cold spells or high wind and rain can lead to increased feather pecking.
This, in turn, means the birds find it harder to maintain body temperature, stress then continues to rise, and feather loss increases, so it becomes a vicious cycle.
7. Patrol fences regularly
Fences should be monitored at least weekly to ensure predators are not digging in and, equally, that hens are not getting out.
Hens will often find their way out through small gaps, but then not find their way back in, becoming stranded and vulnerable to predators outside the range.
As winter progresses, food sources become limited, so foxes and other vermin become more determined to get into the range.
It may be necessary to add extra strands of wire to fences or invest in an electric fence.
The optimum positioning for an electric wire strand is 23cm (9in) away from the fence and 23cm (9in) high, to prevent vermin. This could be positioned along the top of the existing fence to stop foxes getting over the top.
8 Beef up biosecurity
Creating a biosecure unit is crucial year-round, but the autumn and winter bring additional challenges.
Muddy boots and moisture carry disease, which means a bigger effort is necessary to ensure they are cleaned between the house and the range.
Dips should have lids to keep the rain out and prevent them from becoming diluted. It’s also important to realise that disinfectant won’t work once it has been in contact with organic material.
Boots should, therefore, be scrubbed to remove all mud and leaves before they are dipped.
Wheel washes, likewise, cannot be expected to disinfect vehicles if they are caked in mud so this too must be removed. It is also worth checking that hoses are not frozen.
Overall, the safest way to protect the unit is to keep visitors away from the range and then if necessary, providing clean boots and protective clothing at each biosecurity point.
9. Bait with care
Vermin baits around the range perimeter and stores may become necessary as rodents and other species seek out food and warmth.
However, poultry-keepers must comply with vermin control regulations, including holding a certificate to use baits and completing an action plan.
It is no longer permissible to leave poison out as a precaution; there must be a demonstrable problem before it is used.
It means vigilance should be stepped up through the autumn and winter, so the issue can be tackled as soon as possible.