Poultry Husbandry
Egg production systems
History of the laying hen
1960’s –
commercial egg
laying breed
produced approx
200 eggs/year
Wild junglefowl –
approx 60
eggs/year
Now
approx 320
eggs/year
Egg Production Systems
Cleaning and Disinfection of Poultry
Houses
 Insect Control
 Operations prior to cleaning
– Water tank, pipes and nipples
– Clean and de-scale
– Rinse twice with clean water
– All the equipment – nests feeders drinkers
– Entire Ventilation system
– Litter removed
Washing
 Washed, disinfected
 Rodent control
 Assessing disinfection effectiveness
– Visual exam
– Bacteriological
– Resting Period
Good Brooding Conditions
 Day old to POL (point of lay) is critical time.
– Success in rearing house – success in the
laying house
– E.g. delay in growth at 4-5wks will reflect in
bodyweight at 16 weeks and then in mean
performance – e.g mean egg weight
Temperature and Humidity
 Raise house temp to 28-31°C
– Heat losses incurred from contact with the litter
very important in first few days
– 2 gas brooders or 2 radiant heaters advised for
1000 birds
– Temperature and relative humidity should be
uniform throughout the building
Feeding Technique
 The feeding techniques between 4 -16
weeks are designed to:
– Avoid the build up of the fine particle residues
– Rapid feed intake
– Feeding times and rapid intake
Targets in rearing
 To produce a uniform flock and a weight
which is compatible with the intended age at
sexual maturity
 To obtain the correct weight at 4 weeks to
secure frame development
 To achieve steady growth between 4 and 16
weeks with a good development of the
digestive tract
General principles of lighting
programmes during rearing
 Chickens are sensitive to changes in
duration of light:– it will influence the age of sexual maturity
– It will influence feed consumption
Lighting Programme and Growth
 In addition to the influence of growth light
will effect:– Progressive growth of the digestive system
– Gradual adaption to a body clock (e.g.
anticipation of a dark period)
– Lack of night time energy supply when dark
periods are too long
Table Egg Production
Systems
The Laying Phase
16-74 weeks
Welfare – the 5 freedoms
What ‘natural behaviours’ do hens exhibit in
the wild?
• Foraging for food by exploratory pecking and
scratching over distances
• Preening and dust bathing
• Use trees for roosting at night (perches)
• Seek out a secluded spot for laying and build a
nest
• Congregate in small groups with a complex
social order (hierarchy)
All laying birds still have strong desire to display normal behaviours:
Dust bathing
Comfort and
grooming
behaviours
Perching
Behaviours
include:
Nesting
Investigation
Legislation
Welfare of Animals Act (Northern Ireland)
2011
Welfare of Farmed Animals Regulations
(Northern Ireland) 2012
Caged Production
Welfare Regulations
for hens in Conventional Cages
 From 1 Jan 2003 - at least 550sq.cm. cage area
per hen (previously 450 sq.cm)
 Cages are fitted with claw-shortening devices
 From 1 Jan 2003 no such cages may be built or
brought into service
 Existing cage systems prohibited from 1 Jan
2012
 Minimum requirements for feed space,water
space, cage height and slope of floor are specified
See DARD regulation document
or welfare code of practice
DEVELOPMENTS WITH CAGES – The
‘Enriched’ cage is the only cage system
option permitted from 2012
Increase area / hen – 750 cm2
Provide perching spaces – 15cm per hen
Provide nest boxes in each cage
Provide litter (dust bath) in each cage
Abrasive strip to control growth of claws (“a clawshortening device”)
Thicker wire in floors ( wire of standard floors damages
feet)
See DARD regulation document or
welfare code of practice for spec
Enriched vs. Conventional cages
Minimum
space
Enriched
Conventional
Total = 2000 cm2
750 cm2 per hen (600cm2 + nest
box)
550 cm2 per hen
Perches
15cm per hen
X
X
X
Trough
12cm per hen
10cm per hen
Height
45cm
(20cm nest box)
35 to 40cm
Inspection
90 cm between tiers
35cm from floor to bottom tier
Nest
Litter
Egg production performance
(cages)





Laying cycle – 16 to 74 weeks of age
Egg output – 335 eggs per bird
Mortality – 4%
Feed intake - 111 grams per bird per day
Downgrades – 8%
LAYING PHASE- Egg production in cages
Advantages of cages for egg production
• Increased no of eggs harvested compared to deep
litter or free range
• Reduced food consumption as high stocking density
allows high temperatures to be maintained
• reduced labour - easy to mechanise feeding, cleaning
and egg removal
• Cleaner eggs - soiled eggs get a lower price
• Lower mortality - less cannibalism, lower levels of
disease, no mortality from foxes
Welfare advantages
• Better control of intestinal parasites
• No litter costs
• Higher stocking density - lower capital costs
• Ease of management of stock
• No contact with wild fowl or rodents - lower risk of
salmonella, Gumboro disease, Newcastle disease &
Avian Flu.
BUT
• Confined environment
• Not natural for bird
Laying cages have been clear focal point of anti-intensive
farming lobby
Management points
• Sudden drop in food intake indicates a problem
• Compare egg production with standard graph
• Is egg size on target
• Monitor downgrades
• Limit food wastage
• Record mortality
Alternative systems of egg Production
Definition: Alternative systems means alternatives
to cages for lying hens. The alternative systems are
sometimes called colony systems as the total flock of
hens is kept in one large colony
Tiered / Barn
Tier system - Barn System
Achieves a high stocking density by using the vertical
space in a building while improving bird welfare in
comparison to cages
•Commercial tiers are three tiers high
•Perches and nest boxes are provided
•Provision of litter for 1/3 of floor area
Egg production performance
(Tier/Barn)





Laying cycle – 16 to 74 weeks of age
Egg output – 325 eggs per bird
Mortality – 6%
Feed intake - 115 grams per bird per day
Downgrades – 10-12%
Welfare advantages
• Freedom of movement
• Freedom to stretch wings
• Nest boxes provided for
egg laying
• Perches provided 15cm/hen)
• Freedom to dust bathe if
litter provided
Welfare
•Better than in cages
•Hens travel greater distances
•Leg bones stronger
•Nesting
•Perching
•Freedom to stretch wings / fly short
distances
Disadvantages in Comparison with cages
• Floor laid eggs on litter and slats - high labour
• Fewer eggs harvested - approx 7 eggs/hen/yr lost
• More difficult to mechanise egg collection
• Hygiene of eggs poorer i.e. more soiled eggs because laid
in nest -- downgraded
• Extra energy cost of activity - slightly higher feed intakes
• Higher capital costs
Tier system - get a lot of aggression and feather
pecking due to unstable social order. Beak
trimming may be necessary
Hens in tiers were found to be less aggressive
than caged hens - but hens in group pens
without a perch were more aggressive than
caged hens
Free Range
Free range
 Protection
from:
– Adverse
weather
conditions
– Predators
– Risks to health
 Access to:
– A well-drained
lying area at
all times.
Egg production performance
(free-range)





Production cycle – 16 – 74 weeks of age
Egg output – 325 per bird
Mortality – 6-10%
Feed intake – 125 grams per bird per day
Downgrades – 12%
Free range systems
House interior can be in deep litter or tiered
If no litter in house can still dust bathe outside but only where soil is dry enough
Welfarist’s regard free range as the ideal
in comparison with other options.
Free range eggs are perceived to have a
healthy eating image in the mind of the
consumer
Welfare Advantages
As for tiered or deep litter - only also access to pasture
Welfare Disadvantages
Lack of control of environmental temp - exposure to
low temperatures - high feed intakes
Lost eggs
lower egg production - due to low temperatures
high labour costs
Parasitic diseases
Contact with wildfowl and rodents
Predators can give high mortality
Requires land
Lot of aggression and feather pecking
high cost of eggs
Most difficult to control length of day in the
lighting programme
Pop holes
 Pop holes must
be – Along the entire
length of the
building
– 35 cm high and
40 cm wide (at
least)
– 2 m total per
group of 1,000
hens (at least)
Example of a poorly managed range
First Poultry
Jungle Fowl
Breeding Objectives
 Breeding programmes are based on maintaining
separate pure lines “grandparent stock” (generally
of the same breed), and then crossing them in a
controlled manner to produce hybrid offspring.
Selection for improved performance is carried out
continuously within the pure lines.
 Traits such as egg weight, egg numbers and feed
efficiency are assessed. Also: shell colour & shell
strength, resistance to disease.
 Commercial breeding company example
www.hy-line.co.uk
Breeder Lines (4 yrs)
 Pure Lines (genetic improvement /pure lines
 GGP (Great grandparent stock)
(thousands)
(tens of thousands)
 GP (Grandparent stock)
(10 000 000)
 Parent Stock
(400 000 000)
 Broilers
 Processing
 Consumer
Source, McKay 2008
(45 000 000 000)
(70 000 000 tonnes)
Breeding objectives eggs
 Commercial layer- Objectives
 To improve:
- Bone strength
- Egg numbers
- Reduced skeletal defects
- Peak for longer
- Better egg quality later in cycle
- Improved body conformation
- Improved skeletal durability
- Reproductive defects, in terms of diseases, prolapse and double
yokers
- More disease resistance- (EDS Egg drop syndrome)
Table egg Production
 Breeds
– White Leghorn (Italian origin)
– Rhode Island Red (USA)
– Light Sussex (England)
White Leghorn
Rhode Island Red
Light Sussex
Sources of further information
 www.fawc.org.uk (Farm animal welfare council,
makes recommendations for government to
consider when writing legislation)
 www.britegg.co.uk
 www.nfuonline.com
 www.bfrepa.co.uk
 www.bepa.org.uk
 www.nutritionandeggs.co.uk
 www.thepoultrysite.com
 www.defra.gov.uk
 www.dardni.gov.uk – NI Code of recommendations
for the welfare of laying hens can be downloaded
online