Seasonal changes can cause enormous problems for free-range egg producers. As we head into winter, Olivia Cooper finds out to avoid the common pitfalls
Winter can be a difficult time for free-range egg producers as hens tend to eat more, egg size increases, and stress and feather-pecking can become seriously problematic.
But with some careful management, producers can minimise these difficulties and ensure a smooth transition into the winter months.
Mick Dennett, poultry specialist at Humphrey Feeds of Hampshire, says there are three main factors contributing to seasonality – the change in temperature, reduced daylight hours, and wet range conditions.
Colder temperatures directly increase hens’ feed consumption, by as much as 10-15%, says Mr Dennett.
“This will start to increase the egg size, particularly if the hens are on a higher specification summer feed ration.
“If egg sizes increase by more than 2g over the recommended size for the breed and age of the bird, producers need to take rapid action to redress the problem. “It is one of the commonest reasons for feather loss through stress.”
Egg numbers may remain stable, but the higher egg mass can be stressful on the hens and lead to deteriorating shell quality, he adds.
“The amount of seconds will increase to a very high level – easily 20% – which is a major loss.”
Producers should weigh their eggs every week, using a representative sample of eggs laid in the morning, which tend to be 2g heavier than those laid in the afternoon. “If you don’t weigh your eggs every week you are not in control of your egg size and the health of your flock,” says Mr Dennett.
“There tend to be more viruses over the winter months – and the best indicator is reduced egg size. It is the finest way of telling if you’ve got a problem. Don’t rely on egg packers’ weights as there is two-to-three week time lag, and normally a 1g weight loss after transport and handling.”
Birds which are stressed by over-producing can become deficient in nutrients, leading to feather-pecking and even cannibalism.
“Feather loss can create many problems – for one, the eggs turn pale or white and will be downgraded.”
Stress is particularly noticeable in uneven or late summer-reared flocks. “Small birds are pushed even harder when their feed consumption goes up – they are often the ones that suffer the most. These are flocks that will need special feeding to get them to their target weight.”
While larger birds will need to moved from a high-specification summer ration to a lower spec winter ration, to avoid over-stimulating egg size, smaller birds need to remain on a high-spec ration until they reach the required weight, says Mr Dennett.
“Work closely with your feed company to get the best ration for your flock – they are all different and so many things can be tailored accordingly.
“Producers should weigh birds every week up to 35 weeks, to ensure they are meeting growth targets and are not facing a disease or nutrition challenge, he adds.
“If growth rates stop or if the flock becomes uneven, check for disease.”
Reduced daylight hours can impact on the hens’ production, and can slow the rate at which they come into lay and reach peak production. Although producers can change house lighting regimes to artificially control laying patterns, it is not possible to entirely wipe out a free-range hen’s natural reaction to winter daylight, says Mr Dennett.
However, it is possible to manage the state of the range over winter, to optimise flock health and output. “Wet and warm weather is ideal for parasites, particularly on farms where drainage is bad or overhanging trees prevent sunlight reaching the ground.”
Another way to improve the health of the flock is to feed a gut flora additive like Bio-Mos. “This type of product has made the biggest difference to the health of the birds that I’ve ever seen.” They work particularly well on older poultry farms with a higher disease burden, keeping the faeces sterile and the birds healthier, he says.
By monitoring hens’ growth rates and egg weight, producers should pick up on potential problems early. As soon as they encounter a problem, they should consult with their vet and feed manufacturer, and speak to breed representatives for any other advice.
Justin Emery, poultry consultant at ADAS, says one of the biggest problems with colder weather is the effect it has on litter quality. “It is so difficult to keep litter dry and soft when the weather is cold and wet.” Refreshing the litter around pop holes with chopped straw is one relatively cheap option – or producers could look at installing verandas, drains and gravel around the house.
Keeping drinkers in good working order is another way to reduce wet litter in the shed. “Make sure that drinkers and nipple lines aren’t leaking.”
Reducing wind chill
Management of the range is also important, to prevent mud being brought into the shed, he adds. Shelters, decent drainage, and ensuring that guttering is in good order can all help reduce the burden on litter. Installing windbreaks and locating the shed away from the prevailing wind are other useful ways to limit the wind chill factor on particularly wintry days.
“It is air movement over the bird, particularly if it is wet, that causes chilling – not the air temperature itself.”
It is therefore vital to minimise draughts in the shed, while maintaining some ventilation to reduce ammonia and circulate heat. “The best way to increase shed temperature is to shut down the ventilation, but then the environment becomes untenable,” says Mr Emery.
Shutting down some external ventilation fans or vents, and using internal fans instead, can be a good way to eliminate ammonia pockets while avoiding draughts, he explains. But producers who use temperature-based ventilation systems must be careful that they don’t shut down altogether on particularly cold nights. “You may need to fit a cycle timer, or reduce the thermostat to ensure it comes on.”
Very few producers heat their sheds, but in particularly cold periods, or when birds are not well feathered, there could be an economic argument to do so, says Mr Emery. Warmer birds eat less, produce more reasonable-sized eggs, and suffer less stress, potentially leading to reduced disease and better feathering.
“The cheapest way of heating a house would be to use little LPG-powered box heaters.” Hanging fans could also be added to circulate the warmth and reduce ammonia pockets, but good insulation is always essential.
“The best thing to do is go into the house after dark and see how warm it is, and what the environment is like. Is it cold, smelly or draughty? If so, look at what you can do to rectify that.”
Want to know more?
Managing egg size – see Poultry World, p28, April 2007
Shelter – see Poultry World, p28, May 2007
Range management meeting
ADAS has organised a series of free meetings sponsored by DEFRA looking at range management. The series of meetings around the UK will provide an opportunity to discuss a broad range of issues relating to ranging for free-range laying hens. Topics will include: Getting birds to use the range, keeping the range in good condition, maintaining good flock health and how the Nitrate Vulnerable Zone rule changes affect you.
The meetings are free to attend and will commence at 7pm. For more events see our events section.