Alternative Housing Systems for

Laying Hens:

Challenges and Solutions November 18, 2015

Alexandra Harlander DVM, DVSc, PhD, Dip ECAWBM(WSEL)

The Burnbrae Farms Professorship in Poultry Welfare

Significant social concern of our

time: health & welfare of laying hens

The welfare of laying hens

ranks among

the most important farm animal

welfare issues among

citizens,

governmental organizations and

politicians

in North America and EU

(high income levels)

.

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w.

faz.n

et

http://www.parl.gc.ca

legislation

animal welfare = consumer issue

Consumers’ growing preference for

cage-free eggs

private-label eggs

The ideal state of welfare encompasses

Physical wellbeing

(good physical health &

functioning)

The ability to perform innate or

species-specific behaviour

It's psychological (affective)

state

(to minimize unpleasant „affective

states“[pain, fear, etc.] & allow

animals normal pleasures)

Physical wellbeing

Psycho- logical wellbeing

Species- specific behaviour (behaviour they are motivated for)

Adapted from Appleby and Lund

What does that mean for laying hen

housing?

Conv. cages were developed during the

1920`s and 30s to

reduce disease and injuries

due to pecking behaviour.

simplify husbandry by

increasing efficiency.

In the late 1980`s and 1990`s international regulations

began to restrict the use of conventional cages. Why?

Concerns over the welfare of conv. caged hens arised in 2 general areas:

A. prevents the performance of ethological needs (Duncan, 1998)

B. severe restriction to the general freedom of movement (Appleby et al., 1992)

Housing systems for laying hens

Cage (conv./enriched)

Non-cage systems (single-/multi-tier)

Furnished/enriched cages – laying hens

Wire enclosure with extra

space & elements: perches,

nestbox [enclosed nest area],

litter area, extra height

Variety of group sizes:

10-12 birds= small group

15-30 birds = medium group

~ 60 birds = large group

(LayWel 2009)

food trough: 12 cm/hen

Perches: 15 cm/hen

Litter area: scratching/pecking is possible

Nest box:

750 cm2 of cage area per hen; D: 800 cm2 no cage less than 2000 cm2

Cage height: 45 cm; D: 60 cm

©Big Dutchman

At least 2 nipple/cup drinkers

D: Small Furnished Group Housing Systems

Claw-shortening device

550 cm2/hen in conv. cages – EU banned!

Non-cage systems – laying hens

Single-level systems

Multi-level systems (aviary systems)

More space (1.111 cm2 vs. 750/550 cm2)

Perches, nests and large scratching areas (litter)

Large group sizes (e.g. 5000-30.000 birds)

Single-level system

Multi-level system

(EU standards)

Single-tier systems

KTBL 2008

Slatted area

Littered area nests

perches drinkers

feeder

Multi-tier systems =

Aviary

KTBL 2008

• with integrated/non-integrated nest boxes

• several levels of perforated floors with

manure belts under them

• Feeders and drinkers are distributed in such a

way that they provide equal access for all

hens.

Covered verandas/wintergarden

Area near the house

indoors

Covered veranda≠ usable area

Open run;

free range

KTBL 2008

nets

Harlander ©

Harlander ©

Concrete floor, usually covered with litter.

climate is similar to that outside except for rain

covered with free draining material

to maintain good hygiene both outside and

within the house.

Pop holes

UK - accounting for around 48% of all eggs in 2013

Welfare trade-offs among housing systems for

laying hens

http://www.avma.org/issues/animal_welfare/cage_noncage_systems.asp

conv. cages

Non-cage systems

Enriched cages

perch, nest box, scratching area

Mortality

Mortality in laying hens (cage vs. non-cage)

aviary Floor housing

furnished cages

Rodenburg et al. 2008

Generally regarded higher in non-cage systems; (Sparks et al., 2008; Thiele and Pottguetter, 2008; Anderson,

2010, Leenstra et al. 2012)

Mortality in commercial indoor & free range

systems range from 3-12%

5.4% in furnished cages vs. 9.4% in non-cage

systems (Weeks et al. 2011)

2.8% in furnished cages vs. 8% in non-cage

systems (Rodenburg et al. 2008)

Reduced mortality from 22% to 6% in a new free range system after the introduction of

a good management practice! (Shini et al. 2008)

Mortality in laying hens (free range vs. organic)

Leenstra et al. 2012

Overall effect of system (organic vs. conventional free range) on egg production and mortality

was significant, with higher mortality and lower egg production among organic hens.

White hens tended to perform better than brown hens. Silver hens appeared to have a higher

mortality and lower production per hen housed at 60 weeks of age

273 flocks NL, F, CH:

Mortality in brown layers

(cage vs floor housed) in Ontario

Breeds included Hyline Brown (40%), ISA Brown (50%), and Lohmann Brown (10%) strains.

The mean flock size for cage-housed flocks was 15,194 hens (range 5,180 to 30,122),

and the mean for floor-housed flocks was 8,208 hens (range 1,992 to 15,065)

Petrik et al. 2015

1.29 ± 0.19% 2.13 ± 0.42% P = 0.078

Causes of mortality in laying hens

cage/non cage systems

Feather pecking & cannibalism

Health problems

Infections with red mites (EU)

Smothering (Rodenburg et al. 2008)

cannibalism

Epidemiolog. British study – 78% severe feather-

pecking (FP) Lambton et al. 2010

Similar results assumed in other countries Meyer et al. 2012

Primary cause of mortality

Removal of feathers is painful for the victim Gentle & Hunter 1991

Can lead to decreased productivity/increased

feed consumption [more than 40 % extra energy Tauson & Svensson 1980;

van Krimpen et al. 2009]

poor feather cover

poor feather cover

FP-Is it a real problem?

Behavioral disorder:

Oral repetitive

bird- to- bird pecking

one hen pecks at

or

plucks the feathers from

another hen

can lead to cannibalism &

high mortality rates

•

FP - What does feather pecking mean?

up to 78% of laying hens perform feather-

pecking in commercial flocks Lambton et al. 2010

FP in brown layers

(cage vs floor housed) in Ontario

maximum score of 16 (perfect feather cover)

minimum score of 4 (poor feather cover)

22.5 mill hens: 17.6 mill – FP?

Petrik et al. 2015

Cage vs floor n.s.

The risk factors affecting the development of severe

feather pecking in loose housed laying hens

62 UK farms (42% free range, 55% organic, 3% barn flocks)

54% beak trimmed (1. day) + 12,6% retrospective beak trimmed

average: 3000 birds/flock

68.5% (25 wks of age) bzw. 85,6% (40 wks of age) severe feather pecking (SFP)

Lambton et al. (2010)

relationship with SFP at 25 wks and 40 wks

SFP

• decreased with percentage of flock ranging

• lower in beak trimmed flocks

• lower in mash fed flocks

• higher in flocks which showed SFP at transfer

• higher in flocks fed pelleted ration

How does it start?

Causation of feather pecking

redirected behaviour

either from

food pecking (Wennrich 1974)

ground pecking (Blokhuis 1986)

dustbathing (Vestergaard & Lisborg 1993)

Multifactorial process (genetic, rearing, nutrition, lighting, etc.)

Occurs in every type of housing system

Consequences can be worse in non-cage systems where outbreaks can

spread more easily

foraging behaviour

The most important lessons pullets should learn before

they are laying hens is to avoid poor feather cover

….lessons children should learn ….before they are adults…..

Genetic is key! - Healthy, uniform, robust pullets Craig & Muir 1993

Feather -peckers are more fearful Hughes & Duncan 1972, De Haas et al. 2013

• Get chicks/pullets used to low-level

disturbance = Reduces fear and stress

Multiple inspections per day by different people

walking the flock, different coloured overalls,

different routes & talk

• Avoid multiple stressors at the same time

e.g. changing diet and vaccinating

• Matching of rearing and laying

environments

FeatherWel 2013

Management at rear & lay to improve feather

cover – adequate protein & fiber

Feathers: stimulate digestive tract, alter microbiota (Harlander-Matauschek et al. 2006;

Meyer et al. Harlander-Matauschek 2013)

Too little fibre= birds consume feathers in an attempt to replace fibre (Harlander-Matauschek et al. 2006, 2008, Kriegseis et al. 2012) gizzard

High fiber diets affect FP

- Unclear which plant fiber content &

source may be ideal to reduce FP (Van Krimpen et al. 2005)

Diverse group of substances of

chemical and morphological complexity

Mechanism, by which fiber alters FP,

unknown (increased time spent eating=

decreased time to start FP, increased satiety levels)

Fig. Backtransformed mean number + SE of severe feather-pecking bouts/bird/10 min (0-17 wk ) in

experiment 1 (control, 5% cellulose, 5% feather) and

experiment 2 (control, 10% cellulose, 10% feather). P < 0.01 **

**

Kriegseis et al. Harlander-Matauschek Poultry Science (2012) 91 (7): 1514-1521

The addition of 10% of feathers to the diet

reduced FP

feathers chopped into smaller

pieces in a meat cutter

Chopped feathers &

cellulose added to

the diets before pelleting

Management at rear to improve feather cover

– diet changes & pecking opportunity

Every diet change increases risk of FP Green et al. 2000

• Make as few changes to the diet as possible

• Make it a more gradual process providing feeders with diets the pullets were previously on

• New diet is less palatable

• Birds search for other pecking opportunities

Use environmental enrichment (El-Lethey et al. 2000) around the time of diet change

e.g. straw bales for pullets to break down &

keep litter dry

Feeders & drinkers

are easily accessible

Litter quality: scatter grain/

chopped straw-

stimulating & rewarding

Birds work the litter=keeping it

friable

Give the birds perches-

they can escape from

active peckers

FeatherWel 2013

Litter management (rearing & laying) most

effective against FP

Morrisey et al. 2015

Non-nutritive enrichment in cages:

• propolythene rope

• pecking mats

• and two beak blunting boards

The presence of the non-nutritive

enrichments had no significant

impact on FP.

Genetic was key!

Provide high quality, stimulating litter in

loose-house systems

Avoid wet litter may be caused by leaks in the

roof or water system, inadequate ventilation,

high stocking density

FeatherWel 2013

Unavailability of suitable

floor substrate -

Misperceive feathers

as foraging substrate,

peck at and pluck feathers Harlander-Matauschek et al. 2006

UK: 5,120 hens in enriched cages –

Half had trimmed beaks and half untrimmed.

enrichments in cages beyond

the legal minimum

Access to the range (at rear before they are

due to be placed)

http://www.ltz.de/de-wAssets/docs/poultry-news/2012/03feb12en.pdf

Range access has protective effects

against FP (rear & lay) Green et al. 2000; Bestman et al. 2003

Management at rear to improve feather cover

– homogeneity & dark brooders

Flock homogenity Having a range of weights within the flock=fear in the lighter birds =Increased risk of FP

Dark brooders

Prevented FP in the dark brooder

pens, whereas FP rose with age in the

heating lamp pens

Jensen et al. 2006

The brooders run the length of the shed and

the heat stays constant, meaning the chick meets

its own needs for heat.

http://www.fwi.co.uk/poultry/dark-brooding-pullet-rearing-helps-free-range-hens.htm

Low 7 day mortality: 0.5%

Feathering two-to-three weeks ahead of those in traditional

sheds. 100g heavier having utilised 500g a bird less feed

than standard units.

Dark brooders

Heating lamps

Back-transformed least-square mean number of severe and gentle feather pecking bouts + SE

in control ( C) and quinine (Q) treated birds in early laying (E) and laying (LAY)

Spraying bitter tasting quinine on the feather cover -

reduced FP as long as it was detected

Harlander-Matauschek et al. 2010

Beak-trimming -addresses the symptoms of

FP and not the actual cause

FP managed in the majority of commercial systems by

beak trimming - it reduces mortality and morbidity

Practice has been associated with both acute and

chronic pain Gentle & McKeegan 2007, Kuenzel 2007

Considered a mutilation in the EU (Council directive

199/74/EC), although Member States are allowed to

authorize beak trimming in order to prevent FP and

cannibalism.

e.g. The Farm Animal Welfare Council (2009)

recommended a ban on beak trimming

Beak trimming is also not a remedy for FP, since the

behaviour is still evident in beak-trimmed flocks eg. Lambton et al. 2010

Considered in EU as mutilation e.g. legislation in EU not allowed or strictly regulated in EU

Loss of sensory organ

2. Viral, bacterial and parasitic infections

Viral, bacterial and parasitic infections

Viral diseases: consistent fall as a result

of vaccination programs & better

hygiene management

Bacterial diseases: rose as a result of

dust, bacteria & ammonia loading in

litter based systems

(Kaufmann-Bart & Hoop, 2009)

Importance of good ventilation and heat exchange

to extract air pollutants and keep litter dry!

Common foot problems

• Foot pad dermatitis

- Discoloration, necrosis and ulceratio of the epidermis

caused by wet litter, feed, genetic

- 40% of the laying hens in alternative systems (Niebuhr et al., 2009)

• Bumble foot - Infection with Staphylococcus aureus, localised bulbous

lesion in the ball of the foot =severe lameness

(Lay et al. 2011)

• Excessive claw length

Parasitic infections in relation to housing system

(Jansson et al.., 2006)

cages single-tier aviary free-range

%

Helminths: seperation of the hens from their feces

with the use of slatted floors and manure belts under drinkers and perches

Red mites (EU): sealed constructions to prevent red mites nesting

helminths

Red mites

Skeletal health

Osteoporosis prevalent in caged birds due

to lack of exercise accounts of all 20-35%

in conventional cages (Lay et al. 2011)

Fractures of the keel bone are more

prevalent in alternative systems

49-67% in single tier floor systems (Nicol et al. 2006)

50-78% in free range flocks (Wilkins et al. 2004)

Painful! Nasr et al. 2014

moderate keel bone deformities

severe keel bone deformities

It is assumed: break the anatomically exposed keel bone in collisions with perches or obstacles as they jump & fly & land between structures at different heights

On-farm comparison of keel fracture prevalence

in conventional cage and floor-housed laying hens

in Ontario

Petrik et al. 2015

Cage vs floor

Effect of housing systems on

skeletal & foot health

2. Conv. Cages: increased susceptibility to osteoporosis, low bone strength, fractures when

birds are caught

3. Funrished: Bones are stronger from perch use, increased incidence of keel bone

deformities

4. Non-cage: keel breaks of hens ranges from 52 to 73% (Freire et al., 2003;

Nicol et al., 2006) and is likely due to the increased mobility and bumping of the

keel bone when hens move

SCALE= ++++=good +++=medium ++=poor

Lay et al. 2011

Why provide perches? Hens roost at night for protection against

predators

The urge to perch has not been lost in

domesticated poultry Bubier, 1996; Olsson & Keeling, 2000

Hens will perch if provided with a

surface that they can grip

This urge can lead to birds perching on

unsuitable surfaces (wires, cables, cause the

bird to injure itself)

Perches reduces stress, allow birds to

escape from their attackers Yngvesson et al. 2002

Perch design is important for keel bone

integrity & foot health

Perch use:

barn vs. furnished cage

53% vs. 23% (Valkonen et al. 2005)

Management keel bone injuries:

Perch design and construction

Perch shape & diameter

• Between 3-5 cm, rounded profile

• No sharp edges, sufficient space either side of

• the perch (no risk of the claw becoming trapped)

Perch height

• A variety of perch heights should be given

• Vertical distances ≤ 50cm, horizontal ≤ 75 cm

• Angles ≤ 45 degrees can help to reduce poor landings Scott et al. 1997; Scott et al 1999; Scholz et al. 2014

Perch material

• Wood/metal and plastic (can present a slippery surface)

• Coated with a soft material Stratmann, Froehlich, Harlander-Matauschek et al. 2014)

Perch position

• Over the slatted area, less then 45 degrees

See leaflet by Sandilands & Schrader –

With collaborators from the 2014 International Keel Bone Damage Workshop

Skeletal problems

highlight the need for

e.g. GENETIC is KEY (Flemming et al. )

e.g. agility training of young pullets for moving in a three

dimensional space – REARING

house and perch design to take into account the physical

attributes of the hen

e.g understanding locomotion skills in laying hens

too steep and high

aviaries

Soft round polyurethane perches

buffers pressure on the keel

3. Smothering

Smothering in poultry is when

birds mass together;

unpredictable nature Barrett et al. 2014

Avian hysteria: unexplained extreme nervousness,

followed by flight and

then hiding or crowding in corners

and under feeders Sanger & Hamdy 1962

Panic smother: caused by sudden

disturbances such as noise

Nest box smother:

Smothers recurring throughout lay:

Out of 206 farms – farm managers reported:

50% of all their flocks had been affected by smothering Barrett et al. 2014

Smothering

Common problem

No clear affective reduction strategy

can be

reduced by the separation of flocks

into smaller colonies

Block of corners & walking birds

providing pullets early experience

of the environment in they

which lay to reduce fear Consider rearing!!!!!

Take home message:

Welfare problems such as

Damaging behaviour: Feather pecking & cannibalism

Health problems: keel bone injuries & foot lesions

Fearfulness: panic and smothering behaviour

are affected by a combination of housing factors, hen

genotype, rearing, feed, hygiene and other management

factors

All these factors may have considerable impacts on

mortality and performance and may directly or

indirectly interact with each other.

Take home message:

Different housing systems

have different

strength and weaknesses.

It may never be possible to provide

an ideal system because

increasing the opportunities for

behavioural freedom may unavoidably

increase the risk of transmission of

certain diseases/injuries. Sherwin et al. 2010

Take home message:

In regard to welfare

High levels of plumage loss, fractures and

stress

across all systems (caged, barn, free-range)

indicate that modern hybrids have

welfare problems,

which needs to be addresses through

suitable breeding strategies! Sherwin et al. 2010 Social concern!!

Thank you for your attention!