Reducing aggression and floor eggs in cage-free flocks

Allowing birds enough space to express natural behaviors and peacefully coexist is essential to avoiding aggression. | Courtesy Salmet

Cage-free egg farming experts suggest ways to avoid negative behaviors that reduce bird health and productivity.

Arguably the most difficult aspect of the transition to cage-free farming is the re-introduction of the dynamics of hen socialization and behavior to egg farming. Farmers now need to understand it and manage it in order to consistently achieve the healthiest and most productive flocks.

Keeping birds in cages limited activity and allowed the establishment of a social hierarchy inside the cage. Now, birds are free to interact with a larger group and are exposed to a wider range of conditions, which can cause antisocial behavior and lead to lower productivity. Bird experts say the transition requires farmers to spend more time observing the flock’s behavior, understand what conditions are causing negative behaviors, and make the necessary adjustments to the environment.

Roots of negative behaviors

Egg farmers are faced with three key behavior challenges: hens laying eggs outside of the nest, hens piling in one area or smothering one another, and generally aggressive behavior.

The experts said the root causes for these issues come from the chicken’s nature. Bill Snow, Big Dutchman’s aviary system specialist for the U.S. and Canada, said hens – prey animals in their natural habitat – are social animals that are also aggressive by nature, meaning they are flighty and likely to group together for defense and predisposed to exhibit aggressive, destructive behavior toward each other.

Dr. Nestor Adriatico, director of technical services for Hendrix Genetics, said environmental stresses inside the house can contribute to negative behavior too. Poor lighting, ventilation, beak trimming, litter quality, or feeding and drinking conditions, as well as the presence of disease and parasites can also stimulate negative behaviors.

These negative behaviors often don’t manifest, or can’t be observed and understood, when walking the house during routine management. Farmers need to sit and watch for a few minutes to see how the birds behave and interact on their own. That way, farmers can better understand the specific challenges, what in the environment may be causing them, and how they can change the conditions to control them.

Taking steps to control aggression

Aggressive behavior, like cannibalism and vent pecking, will always be present in hens, but farmers can change the environment to contain it.

Snow said taking steps to avoid aggression is the most important thing cage-free farmers can do to foster a healthy, productive flock. However, almost everything in the house can trigger aggressive behavior. He listed stress, lack of space, litter quality, lighting, temperature, flock migration, lack of proper feed ingredients or feed amount, lack of movement, or poor management.

Proper lighting is important because excessive brightness can stimulate aggression. When aggressive behavior is present, Dr. Anna Concollato, of FACCO’s poultry science technology department, and Adriatico said lighting intensity should be reduced. Red lights can help with aggression, too.

Birds also need room to express their natural behaviors and space to escape aggressors. Snow said hens are calmer when there is more empty space to move around. Potters Poultry said birds behave best when they have plenty of room to dustbathe and express natural behaviors. The experts agreed perches are necessary to add usable space inside the house and give less dominant birds an escape route from aggressors. 

Perching allows less dominant birds to escape more aggressive ones, creates more usable space inside of the layer house, and helps alleviate possible piling. | Courtesy Big Dutchman

Regular walking of the house, generally recommended in cage-free farming, can help with aggression as well as other issues. Potter said regular trips down the aisles and more time spent with the flock by farm workers will reduce flightiness and the birds’ stress level when humans are present in the barn.

Feed and water access and aggression

Diet plays a role in aggression. Concollato said the level of energy, protein, amino acids, calcium and salt in the feed ration must be in balance. She said low salt and calcium levels in the feed generate cravings that result in more pecking behavior. When adding sodium, Adriatico said, farmers should shoot for about 0.5 to 1 kilogram of salt per 1,000 liters of water. He recommended administering extra vitamins, minerals and amino acids through the water supply.

Enough feed and water should be supplied to limit competition that can stimulate aggression. Along with promoting uniformity and avoiding dehydration, feed and water plans need to be designed to minimize aggression.

Concollato said the feeding program can be modified to limit the number of feedings on the top tier of the system. Birds should be motivated to move down to lower tiers to feed, instead of crowding the top tiers. Frank Luttels, sales manager for Volito, said farmers can use a device that shakes roughly milled grain onto the floor periodically. By dispersing some feed onto the ground, hens are stimulated to scratch around and forage rather than peck.

Providing enough feeder and waterer space reduces competition, and potentially aggressive behavior, between hens. | Austin Alonzo

Using diversions to control aggression

Aggression can also be addressed through diversions, or simple devices that attract the hens and give them something to peck at. Diversions can be simple, like hay bales left in the aisles and scratch areas, or more complex, like compact discs hung on string inside the house. The idea is to give the birds something to do besides peck at each other.

The experts said hay bales can be used as diversions. They can add additional fiber to the hens’ diet, but they require an additional expense and bring possible biosecurity risks into the barn. Luttels and Snow said a hard cement block can be used to give the birds something to peck at and to blunt their beaks. Luttels said this is a popular option in Europe, where beak trimming limitations are rising.

A possibly cheaper option is to look around the farm and find something that may work as a diversion. Concollato said improvised devices include string hung from the system, plastic bottles and other objects left in the house simply to entertain the birds. Potters recommended using a five-gallon bottle with black dots drawn onto it to attract the birds’ attention.

Potters said not to use diversions that hang from something, as they can excite and scatter birds, leading to injuries and piling. Suspended discs can create good interest, but light reflected around the barn can excite birds and cause some birds to be pecked due to reflected light showing up on them. 

Methods to avoid floor eggs

To avoid floor eggs, farmers need to start early. When pullets are maturing and coming into lay, steps must be taken to train the birds to consistently use the nest boxes to lay eggs. Conditions inside the nest must be attractive, and conditions outside must be made unattractive or inhospitable for egg laying. Breeders are working on improving a hen’s nesting ability, but for now birds want to lay where they feel comfortable, and sometimes that’s in the litter or in the system.

Farmers must set up the proper conditions to encourage layers to use their nests rather than lay system or floor eggs. | Austin Alonzo

When the lay begins, farmers need to search diligently for floor eggs and mislaid eggs and collect them as soon as possible. Birds want to lay in clutches, meaning one mislaid egg is an invitation to more. When birds are laying, they should not be disturbed. Neither feeding nor flock inspections should take place at this time. Concollato said litter should be kept shallow enough – or no deeper than 2 inches – that hens won’t want to lay in it. Dark corners and areas should be limited, or blocked off, to avoid becoming nesting areas. When allowed, farmers should consider using electrified wires or other pen dividers to keep the aisles separated and prevent birds from laying under the system.

Nests must be attractive to the hens and easily accessible. Adriatico said ramps should be used when possible. Feeders and drinkers should not be a physical barrier between the bird and the nest. When birds are laying, farmers should observe and find out where mislaid eggs are collecting. Those areas should then be denied, using an electrical device or a physical barrier made of plastic or wire.

Potters said the feeders should be run first thing in the morning and then not again until later in the morning. After the first feeding, the hens experience a four-hour peak laying period. When birds are first coming into lay, minimal disruption during this period is needed to establish nesting habits and avoid the tendency to lay floor and system eggs. Too much feeding during this time can draw birds away from the nest and lead to more mislaid eggs.

At dusk, birds should be encouraged to climb up into the tier and roost overnight. This can be achieved by using a phased lights-out program where lights under the system turn off first and lights on the progressively higher tiers turn off afterward. If necessary, birds should be physically moved off the floor and onto the higher tiers.

As the flock ages, Potter said, regular walking of the house and removal of floor eggs will keep mislaid eggs limited. Persistence is necessary because the flock will need until it is 30 to 32 weeks old to settle into its laying habits.

Controlling space and climate to avoid smothering

Piling, also called stacking or smothering, is when a mass of hens crowds into a single area due to fear, excitement or a common need to evade danger. While it’s a routine phenomenon and the potential reasons are legion, it’s unpredictable with potentially serious repercussions for animal welfare and overall productivity.

Piling is an unpredictable phenomenon caused by fear, excitement or a common need to evade a perceived danger. Documenting occurrences and addressing specific causes for piling can help avoid the problem in the future. | Austin Alonzo

Concollato said the motivations for piling include an area being too hot or too cold, too bright from sunlight entering the house, or birds being too panicked from farm workers entering the house. Adriatico said birds may also pile because they feel curious and attracted to something new in their environment. Sleeping behavior, he said, may also spur piling as birds will crowd together to keep warm during the night, maintain a social link or form a common protection against a perceived danger. Concollato said when piling is observed, farmers need to document where it happens, figure out the reason behind it, and take steps to solve that specific problem.

Adriatico said several methods help avoid the issue:

• Corners in the house should be limited or blocked. Wire mesh-covered triangles or electric devices can be used to keep birds out of these areas.
• Light distribution should be as even as possible, and light must not leak in from outside.
• Construction partitions should be built with wire mesh to prevent suffocation if a bird is trapped against a partition. Electric fencing can be used to discourage collection around partitions.
• Music can be played in the house to keep the birds from being too excited by unfamiliar noises.
• Birds should be fed one hour before the lights go off to assure they are spread evenly about the house near dark.
• Enough perch space should be provided for the birds.
• Ventilation should be kept consistent to create a uniform airflow and temperature and avoid drafty areas.

EGG INDUSTRY’S CAGE-FREE MANAGEMENT SERIES

The U.S. egg industry is rapidly shifting to cage-free husbandry, and Egg Industry wants to help farmers gain essential bird management skills in order to ease the transition from caged to cage-free operations.

Since January, WATT Global Media has interviewed and surveyed members and allies of the global egg industry to formulate a basic set of best practices for cage-free flock management that will be published in the coming months in this magazine. This first story focuses on pullet rearing, the most important aspect of raising a successful cage-free flock.

This story was written with input from the following companies: Big Dutchman Inc., Hendrix Genetics BV, Jansen Poultry Equipment, Officine FACCO & C. Spa, Potter’s Poultry International, SALMET International GmbH, and Volito BV – now part of Chore-Time parent CTB Inc., Valco Companies Inc. and Northeast Agri Systems Inc.