Poultry behaviour I.

(Especially of the domestic chicken)

Andras Adorjan DVM MRCVS

Department of Animal Hygiene, Herd Health andVeterinary Ethology

Domestication of the chicken

Domestication: several definitions- Domestication is affected by genetic changes influenced by inbreeding, genetic drift, arteficial selection and natural selection in captivity.- Behaviour of the species is very important in case of domestication and many species that has undergone domestication have some characteristics in common.-Mean characteristics of domesticable animals (Keeling and Gonyou):

Large social groupHierarchical group structure (decrease the aggressiveness in

captivity)Promiscuous mating (not live in pairs)Precocial young (leave the nest after hatching and self-suppliers)Short flight distance to humansOmnivorousNot easily disturbed by humans or sudden changes in environment

Easy to keep them in captivity with good production rate

Origin

Gallus (genus)1. Gallus gallus (Red junglefowl) 2. Gallus sonneratii (Grey junglefowl)

3. Gallus lafayetii (Ceylon junglefowl) 4. Gallus varius (Green junglefowl)

- Until 2008 Red junglefowl was believed to be the sole ancestor of the dom.ch. (dom.ch.= domesticated chicken)

- Eriksson investigated the origin of the yellow skin that is abundant among dom.ch. In 2008 he found that this trait came from the Grey junglefowl. Probably the dom.ch. is a hybrid of this two species.

(But I think the investigation go further and we need little time until we find out the real truth.)

Domestication process started at around 8000 years ago in the South and Southeast Asia and probably started out simultaneously in different countries in Asia.

Featherless chickens after genetic modification for better heat transmission

Changing of the performance of the scientifically selected breeds in the last few decades..

Behaviour of the red junglefowl

Hen: 800gr (Leg horn is about 1,5kg)

Big sexual dimorphism with male larger than female and more colorful.(female: mostly brown, male: red on the neck and back and have long black feathers on the tail)

It wasn't domesticated, so they behave unaffected by humans.

They are very precautious and after disturbing they roost very high till the next night and they also reduce crowing.

Not only the male decide which individuals the flock will consist of. The female relationship is also of great improtance for the bonding in the flock.The hierarchies are sex-specific. High-ranked male have more access to females and more vigilant than a low-ranked males.

They live in harem-group. (one dominant male, one or few subdominant males and a couple of females /sex ratio: 1:1-1:4/)

The structure of the harem-group is changeing during the seasons.

(During the breeding season the females leave the male to incubate and raise their broods alone. During this time male-only groups can be formed.)

Direction of the domestication of the chicken

There are three types of chicken: egg-laying type, meat type, dual purpose

In the last 30-40 years there is a very quick breeding process which prefered only some trait (productivity) instead of others.

With this breeding chickens started to produce more frequently inadequate behaviour (agonistic, boredom, frustrated) and some specific health problems (leg disorders, injuries).

The new breeds require more sophisticated systems for the production. So the environment changing have to be followed the changing of the breeds

We are keeping poultries in captivity and provide anything (food, water, heat, good air quality) for their accepetable production.

Some facts about the chicken

Egg production started around 18 weeks of age of the chicken and continue it for 48-50 weeks (~340 eggs/year).

Meat production requires only 35-42 days for the end wieght (2,1-2,8kg slaughtering weight, FCR: 1,7-1,9 kg/kg)

Incubation time(day)

Egg number (egg/hen/year)

Egg weight (g/egg)

Chicken (Meat) 21-22 130-180 58-60

Chicken (Layer) 20-21 270-300 57-62

Chicken (dual purpose) 21

Turkey 27-28 70-100 70-90

Guinea-fowl 27-27 70-90 46-52

Common duck 27-28 120-260 80-100

Muscovy duck 35 80-90 70-90

Mulard duck 31-32 - -

Goose 29-31 35-60 160-200

Pigeon 16-18 2/brooding 12-25

Quail 16-17 280-320 10-15

Poultries' egg production and weight and incubation time

Senses of the chickens

Vision

Panoramic vision of 300°, but only 26° binocular vision with 3D sight. They have excellent sharpness of vision.

Colour vision of the chickens is very similar than humans, but they are most sensitive to green colour.The contrast in colour is very important in attracting chickens to food and water.

They prefere the blue objects with red. (>orange, >green)

First reaction for the light starts at 17 days of incubation of the egg.

They prefer to peck round and small (0,3cm) objects but they also like to consume large ones which has a rhythmical movement or noise.

The selection of the food is based on visual cues. Changing of the food particles (due to changing ingredients of food) can decrease the feed intake.

Hearing

They don't have ear lobe and it is located behind the eye and a tuft of feathers protect the its openings.Hearing ability between 60-12000Hz.Between 250-5000Hz are used for vocal communication.They have several type of calls for different purpose.

Few days before the hatching the embryos start to produce sounds which help to synchronise the hatching of the eggs which layed in different times. Embryos also can produce distress calls which attract the brooding hen and they emit pleasure calls.

The call is more useful communication in the rainforestthan the visual communication.

(It can go more far away than the speech.)

Chicken distress call: loud, high frequency call (attract the attention of the hen)

Clucking sound of the hen: low frequency, short duration, repetitive call

alarm call,laying calls,

nesting calls,territorial calls,

threat calls,cock crowing,

etc.

Smelling

They have very limited smelling ability.The strong odours can't repel them.

(They also have small olfactory lobe in the brain.)But very few knowledge about it until now.

a. Emu b. Kiwi c. Barn Owl d. Rock Pigeon

OB: Olfactory bulb

Taste

Poultries have approximately 300 taste buds (humans have 9000) and they can discriminate between strong tasting compounds.They will reject water which above the 35°C, although they drink cold water.Chickens and pigeons are tolerant to bitter taste. Chickens eat dry foods, and produce less salive which cannot solve the tasting compounds and also have a quick swallowing. (They have poor tasting ability.)

(a) palate,

(b) tongue and floor of the oral cavity

(c) tip of tongue moved to the side to show taste buds on floor of oral cavity

Each dot = one taste bud

Touch

Birds are responsive for the touch. Females often show sexual crouch when are touched on the back.

There are several tactile corpuscules in the beak and surface of the mouth and tongue. They can help to identify the consumed foods.

Chickens like the seeds and solid foods (particules above 1-2mm), and smooth, soft greens.

Ducks like the wet, friable, pelleted foods and don't select between greens.

Geese: dry and soft seeds, new growings of greens (closer to the chicks)

Drinking behaviour

Poultries has a split in the hard palate, therefore they cannot make vacuum in their mouth for sucking. They dip their beak to the water and with closed mouth lift their head to swallow it.(They drink water in small portion.) Flat surface of the water is not attractive for the day old chickens. But if they can see something floating or sank they try to pick them and discover the water.The colour contrast of the drinkers is also very important feature for dicovery of water.

The troughs are better for the day old chicks.

Good level of lip of the drinkers are at the bottom of the bird's wattles. (And at least 1 cm depth with water in the troughs)The correct height of the drinkers is essential to avoid the spillage and the good water intake.

Dehydration can be a big problem of the chicken after the hatching.

Increasing the chance of dehydration: a, high temperature at the hatchery, b, low humidity at the hatchery, c, high early temperature of the brooder, d, thin shell of the eggs, e, incorrect handling of the eggs before hatching

Therefore as soon as you can you provide clean, cool, good quality of water to the chicks.

The recent research has shown that the type of the drinkers are not as critical as the availability of the water. (Sudden change of the type of drinkers can result in some birds failing to learn how to use them for a while.)

Eating behaviour

The vision is the first sense for the decision to consume something. After they peck it they decide with the tactile receptors in the beak that it could be consumeable or not.

Chickens inherently know how to peck objects. But they have to learn how they can discriminate between what they should or should not eat. (It is largely by trial and error that they find out the difference. With brooding hens chicks learn from her what is consumable or not.)Therefore they require easy access for the food and deny acces to material other than food. (taking food on paper on the floor for 1 day)

They have crop for the food storage and softening the food with water. They eat quickly the food at the first 5 minutes, but after that they start to select the prefered parts. (The incorrect size of the particles of the food or too fine food can cause wastage of food.)

The commercial poultry are usually fed a mixed feed that supplies the proper balance of nutrients. However poultry have the ability to balance their own dietary requirements if the main ingredients are provided separately in different drum.

Preferencies of seeds

Chicken: wheat>maize>barley>rye>oat

Duck: maize>wheat>barley>oat>rye

Goose: oat>wheat>barley>rye>maize

Heat requirement

After hatching they require high temperature around them. (32 ºC) But in every weeks it can be decreased with 2 degrees to 20 ºC.(turkey 35 ºC, duck, goose 32 ºC at 1 wk, 24 ºC at 2wks, 20 ºC after)

In the natural environment the chicks take rest under the brooding hen's wings and breast which provide enough warm and dark for quiet sleeping.

The modern poultry keeping provide the required heat with brooder stove or with warm air in the building or with this two mixture.

The modern meat breeds of chickens produce so much heat in the finishing period (very quick metabolism) that they need good air changing.

Low temperature can cause poor immun development (slow yolk sac resoprtion), poor growing, poor environment quality (ammonia, wet bed)

Behaviour changing in the different temperature

Using guard in the first few weeks around a smaller group of poultries in order to avoid suffocation of birds in accidentally caused frightening.

Social behaviour

Individual recognition

Fowls can recognise each other. The recognition is based on the shape of the comb, wattles and head generally. Colour changes in plumage are identifiable. (Intensive colours are more noticeable.)

Only very abrupt, major changes results in a failure to recognise flock mates that have been altered.

However they forget each other very quickly, only after 1-2 months (sheep: 2 years)

Communication

They use variety of sounds for communication. The most common sounds are food calls, predator calls, pre- and post-laying calls, rooster crowing, distress call of the chicks, clucking calls of the broody hen.

They also communicate with others by displays and changes in posture. (head up or down, tail up and down, feathers spread or not spread)

Communication plays an important part in the maintenance of individual personal space, flock organisation and integrity in a group situation.

Pecking and peck order

Fowls use pecking in several situations for different purposes.

They peck to escape from the shell, to feed, to drink, to obtain and keep personal space and to establish relationships.

Beak trimming changes their ability to peck. They cannot pick food particles from hard, flat surfaces. The food and water suppliers have to provide enough depth that the birds are able to obtain sufficient quantity of both.

T. Schjelderup-Ebbe recognised the social hierarchy (pecking order)in the chicken flocks in 1921.

The hierarchy organisation starts at early age (10-16 weeks) with pecking of the subordinated members of the flock.

(Important: this pecking doesn't cause injury and it doesn't have intention to pull out feathers /feather pecking-abnormal behaviour/)

(There isn't problem with this trait in the meat production because the slaughtering age of them is at 6-7 weeks of age)

The aim of the hierarchy establishment in the flock is to stabilise the relationship between the members (dominant-subordinated) in order to

decrease the aggression level in the flock.After short time of establishment of hierarchy it will be stable

for long period.

New member of the flock starts again the organisation of hierarchy. (Try to avoid the altering of the compositon of the flock during the

production. Place the layers few weeks before the production starts to the laying house. Give adequate space for eating, drinking and nest

and floor space.)

Basic behaviour traits

Roosting and perching

It is an inherited protective mechanism against ground predators.But now there isn't necessary to use perches for this reason.

However the existance of perches provide many advantages.

1. The replacement layers can learn the usage of the perches and strenghten the legs.

2. Perches before the nesting boxes decrease the floor egg number.

3. Perches provide chance for the birds to rest without harassment from the pen-mates during the light periods.

4. The development of the ' perchery' system of housing permits a siginificant increase in the number of birds that will comfortably occupy the house.

Preening

It is also an inherited behaviour trait to maintain the condition of the feathers.This activity includes dust bathing, oiling (from the uropygial gland /preen gland/) and preening with the beak or foot.Dust bathing helps to realign the feathers and rid from the external parasites.The oiling is very important in the water fowls for the good water protection of the feathers.With the preening they reorganise the connections in the feather flag.

https://www.youtube.com/watch?v=BQxl-UFcPI4https://www.youtube.com/watch?v=F19I3y4IWRU

Reproductive behaviour

Chickens generally reach the maturity at 16-18 weeks of age,but it depends on the strain, nutrition, lighting program.(Hen only lays eggs if the light above 9hr/day. Restricted food supplying cause delay in the maturity. Meat strains will be mature later than egg layers.)

In the nature they live in a harem (one dominant cock and few subordinated young one and a couple of females).

But in the industry we keep them in larger groups with 8-10 males/100 hens (meat type) and 10-12 males/100 hens (layer type) ratio.

After a 12-15 eggs the hens cease the egg laying and start to brood in the normal situation.

(The modern breed was selected for non-broodiness, because it decrease the egg production.)

Only the hens incubate the eggs and provide exact heat and humidity for the eggs and she also makes egg turning.

Once a day she leaves the nest for the elimination and eating.

After the hatching she provide heat, shelter and show the consumable food for the offsprings.

The connection between them will be broken after 8-10 weeks and hens rejoin to the original group.

The egg laying period prolongs to 48-52 weeks in the modern strains with 320-340/year eggs production.

Hen can adopt strange chicks until 3-5 days after hatching.

Most mating occurs after mid-afternoon.

Events which can influence the males reproductivity:1. Light breed male are more active but have lower sperm counts than heavier genotypes.2. Initially the higher rank male mate frequently.3. Increasing day length will stimulate semen production. (Although normal day length is sufficient.)4. Water deprivation for 48hr or more will lead lower semen production for up to 6 weeks.5. Mouldy food may result lower sperm quality.

Hatching synchronisation

Activity of the embryo starts at 17th day of the incubation. In this stage the embryo is located so that the head is under the right wing and the beak directed towards the aircell in the large end of the egg.Before the hatching the chicks pierce the aircell and start to breathe and the vocalisation which can synchronise the hatching process between the eggs.

https://www.youtube.com/watch?v=PedajVADLGw

Nesting behaviour

The free living hens look for a quiet, dark place where they can lay and brood their eggs. (after 12-15 eggs start the brooding)

In the industry the nest place is also very important for more and better egg quality. (Floor eggs are dirty and may be contaminated by pathogens.) The nest also can provide a quicker and authomatical egg collection.Floor eggs can induce egg eating behaviour (abnormal behaviour). Two types of nest: communal and single nest. (The shy hens may be disturbed in the communal nest. Less nest requirement and quicker egg collection in the communal nest. 1 single nest for 5 hens or 1 communal nest for 50-60 hens.)

Nest: provide parasity free environment, with good litter quality and dark or shadow (The hens chose always dark and quiet place for the egg laying, therefore the darkness of living-area are always avoided that they choose the nests for laying.)Egg collection frequency is 4 times/day.

Egg laying

1. Before the egg laying start to look for quiet and dark places for it.

2. If they found it they examine it carfully and make a circular hole for the eggs with their beak and their abdomen.

3. Take a little rest and calm down before the laying.

4. Egg laying in standing position.

5. Examination of the layed egg with their beak and place it the centre of the hole. 6. Cackling for a minutes

https://www.youtube.com/watch?v=nAFtZAMZb7c

Possible problems around laying:

1. There isn't enough nest boxes.

2. There isn't chance to explore and learn the nest usage before egg production.

3. Some hens choose the nest for resting and expel the other ones.

4. Timid hens can't find adequate place for laying and do it on the floor.

5.There isn't roost before the nest which help to examine the nest before the laying and also give chance for looking for free nest without they disturbe the occupied nests.

6. In cage keeping the problem can be that they don't have quiet place for the laying and to show the normal laying behaviour which can possible cause frustration for the hens.The opened cloaca after laying can initiate the cannibalism with pecking of the vent.

Molting

In every year after the egg laying period they start to change their feathers.

(It can provide a new good cover around the body and help to rid of the majority of the parasitic insects.

It require almost 8 weeks for totall regain of their covers.

This is the phase for the refilling of the stock of the body and taking a little rest.

Abnormal behaviours

Feather pecking

Cannibalism

Egg eating

Brooding(Normal behaviour in the nature,

but not tolerated in the poultry farming.)

(Floor laying)-management andkeeping problems in the background

Feather pecking

Someone start to pull out and eat the others feathers.They also can eat the feathers from the floor.

This behaviour can cause bleeding and harassment for the sufferers and crop impaction for the active member of the behaviour.

There was many idea about the possible underlaying causes:overcrawding, poor air quality, too high temperature, too high

humidity, less food and drinking place, too intensive lighting, sick animals in the flock, nutrition imbalances

With the corrigation of these above events the problem can be decreased but totally never be solved.

(It has a complex origin of cause.)

New idea about the possible cause:

Fail of the social synchronization. (Social synchronization of the group living animal has a major advantage as protection against predators and exploitation of

resources. /↔solitary animals/)

The flock will be active and inactive in the same timewith the help of the synchronisation.

Chicks which have been brooded by hens have a more proper synchronaiztaion and in the later life they spend more time in the

proximity of each other.

Growing up with broody hen: she organize their chicks activity, she directed to eat, drink, sleeping, walking.

Resting in the dark is a crucial factor for synchronization. (Chicks with dark brooder have better synchronization than chicks

without it.)

Cannibalism

After the laying the cloaca is open for a while and the sight of the red tissue can initiate the picking of it.

This behaviour may become more intensive afterwards and they pick the another animal any time without real reason.

Solution: Hens require enought nesting place where they can lay the eggs without disturbance and can take a little rest after it in order the

cloaca will be closed.

Egg eating

Possible causes:

-Low calcium level of the food causes thin egg shell.

-Floor eggs and cracked eggs give a chance to taste the eggs.

-The imbalance of nutrition and low calcium level of the food also can increase the looking for another

resources for balancing the ingredients of the feed.

-Not frequent collection of the eggs also provide chance to eat eggs.

Floor laying

Reasons:

-There isn't enough place for the laying.-There are dark places besides the

nests or in the pen.-Some hens use the nest for resting,

not for laying. (decreasing the nesting space)

Effects:

-Dirty eggs which need washing-Chance for egg eating behaviour

-Egg collection is fatiguing

Brooding

Hens can be genetically selected for this trait.

The modern breeds very rarely have intention to brood.

Before they start to brood they shed the feathers from the breast and abdominal region for the better warming of the eggs.

Goose and duck very good brooders and they can be used to brood other eggs then own one.

Brooding is also very frequent problem in the turkey industry.

Giving up brooding

The poultry was placed in a light nest with cold floor (without straw).

Keeping systems

1. Non cage systems

A, Single level systems:

a, Deep litterb, Fully slatted floor

c, Combination of the above

B, Multi level systems:

a, Multi-tier or aviary systems

2. Cage systems

+1 Combinations of these systems with pasture (outside run)

Deep litter

Especially it is used for meat chickens and breeding.(It is better for the leg and the copulation because the copulation can

only be happened on that surface.)

The animals can be kept in large groups. (70000)

It can be combinated with wire floor in the breeding stock. (improving the hygiene)

Litter material can be straw or soft wood shaving.Litter is sterilized before the stocking of the animals.

32kg/m2 to 42kg/m2 (Depends on the previous seven crop mortality rate and animal welfare indicators.)

Furnished cage (Alternative or enriched cage)

The space is minimum 750 cm2 per hen

with 600cm2 have 45cm free height.

There is a nest and 15cm perch per hen, 12cm per hen

feed trough and claw shortening, dust bath and friable material to perform

normal pecking and scratching behaviour.

(There are other national regulation which have

higher requirement of the keeping.)

Aviary systems

Floor is covered with friable material for normal scratching and explorative behaviour.

Birds have access for this site only during the daytime.

Three or four level for different requirement. (nesting, eating, drinking, resting.)

Disadvantages:High risk of cannibalism and keel bone distortion and fraction.

Only such layers can be settled in this system who were reared in the similar system.

(They had chance to learn and adapt to this system.)

Advantage:Better animal welfare

Comparison between barn and free range keeping

Chickens in the free range system have better air quality and more space for activity.

The animals more active than the barn keeping. (bigger hippocampus)

The outdoor run help to reduce the feather pecking and cannibalism occurance and mortality from these reasons.

But the free range system has disadvantages as well. It has chance for predation and has higher incidence of bacterial (Pasteurella, Salmonella, Histomonas, etc.), helminth and parasitic (red mite)

infections.

Comparison between non cage and cage keeping

In the cage they have less chance for motion and also less chance to avoid the aggression of the cage-mate.

These disadvantages can provide more chance for feather pecking and cannibalism.

The furnished cages has lower mortality rate (3% vs. 8%) and lower incidence of keel bone fractures and lower air-borne dust

concentration than non-cage systems.

The egg shell (4.75 vs. 4.98 cfulog) and egg content (1.9% vs. 2.3%) contamination is lower in the cage systems.

FCR is higher in the non-cage systems than in the cage systems.

Both of the two system have advantages and disadvantages as well but neither is good or not.

Both of them need further improvement.

Adaptation for the future

There is a requirement to find the middle point between the productivity, production in the hygienic environment and animal

welfare.

The Rondeel system tried to combinate all of the advantages of the systems and also serve the animal welfare.

This system provides large, indoor pecking and scratching area on arteficial grass and a smaller forest-like outdoor run which can be

closed in case of health or food safety risks.

Selection for low mortality results less fearful and less sensitive birds with showing less cannibalism.

Improving rearing methods: provide dark brooders (imitation of hens), rearing environment should match the laying environment as closely as

possible, early acces to litter and perches in extensive systems.

Thank you for your kind attention!