Poultry Production

Question 1

The Domestication History of Chickens

Answer 1

Chickens were the first domesticated animal • Approximately 8,000 years ago
• Ancestor - red jungle fowl (Gallus gallus)
• Still runs wild in southeast Asia
• Likely to hybridised with the gray junglefowl (G. sonneratii) to create modern day chicken

Domesticated by the Ancient Egyptians, Romans and Chinese.
The Romans are thought to have brought chickens to Britain.

Question 2

Expansion of the Poultry Industry

Answer 2

Units sizes during the 1940s - late 1950’s were approximately 500 birds
Birds were dual purpose
Housed free range with natural light
Poultry production in the UK was at a very small scale (compared to modern standards) until the 1950s.
Dual purpose means for laying eggs and producing meat.
Derationing of wheat allowed for increased flock size and increased economies of scale.
Electric lighting allowed birds to be kept indoors on deep litter systems.
The USA developed a broiler bird, which lead to the development of specialised meat and egg laying facilities. This is how the industry is operated today.

Question 3

Main types of poultry production include:

Answer 3

Eggs (layers)
Meat (broilers) - chickens, ducks, geese and turkeys
Breeding stock, for both layers and broilers
Further uses of feathers should be explored – currently they don’t supply the feather industry (for clothes or pillows) but alternative uses are being developed for use as a wrapping “paper” material, biodegradable plant pots and building insulation.
Typically the UK incinerates or landfills feathers (2,000 tonnes per week (2016)).

Question 4

Development of Laying Hen

Answer 4

Post-1950’s a medium hybrid brown laying hen was developed
Deep litter indoor systems in late 1950’s to 1960’s
This lead to battery cages being developed
Today’s hens:
A hen weighs 1.6 - 1.65 kg at point of lay (POL) and approximately 2.0 kg at slaughter
Each hen lays approximately 290 - 300 eggs during productive life

Question 5

Laying Hens

Answer 5

Productive life of a hen is 72 - 74 weeks of age. Hens have the potential to live far longer than this, but egg production and quality decreases.
Is the UK self-sufficient in egg production? No.

The UK farms approximately 41 million laying hens

Annually, the UK produces approximately 11,139 million eggs
Imports approximately 1,897 million eggs
Exports approximately 188 million eggs

The UK is 87% self-sufficient in egg production

Management systems – cages, barn or free-range (could be traditional or organic)

Question 6

The Global Perspective

Answer 6

In the last 30 - 40 years global egg production has tripled
In the 1970’s, most of the eggs were produced from North America and from Europe
Today, most of the eggs are produced in Asia and the USA

Date from 2018.
Production is driven by costs.
China continues to lead the way, producing 466 billion eggs in 2018, which represents 34% of the global market.
Global production - 76.7 million tonnes (24% increase over the last decade).
Cultural differences play their part - America produces white eggs.

Question 7

Egg Production

Answer 7

Production distribution:
Laying cage - 44 %
Barn - 1 %
Free range - 54 % (of which 2 % is organic)

Total value - £1,035 million per year

Market breakdown:
Retail (shell eggs) - 56 %
Egg products (eggs processed for food manufacture/foodservice) - 21 %
Foodservice (shell eggs) - 23 %

Question 8

Rearing Laying Hens

Answer 8

Day old chicks (females) are reared to POL (18 weeks) at a pullet rearing facility
Reared in cages or on deep litter depending on later production system
Receive vaccinations and treatments during rearing (3 vaccinations for Salmonella for Lion Code)
Receive 8 hours of light per day (prevent early sexual maturity)

Pullet is the name given to a young hen before she starts laying.

Question 9

Laying hen Transfer to Laying Site

Answer 9

Before first egg
Third Salmonella vaccination at transfer
Weight loss can be 5 - 12 %
Transfer is a major stress - change in environment, temperature, humidity, equipment etc
Hens need time to adapt to new environment e.g. nipple drinkers and increased daylight hours

Transfer should be undertaken as quickly and smoothly as possible. Ideally less than one day.

Question 10

Generic Housing Considerations

Answer 10

Feed consumption should be continually measured (control for health and feed quantity)
Layer feed is higher in energy than pullet and pre-lay feeds (prevents reduction in nutrient intake in early lay)
In early lay, addition of oil to feed can give larger eggs
Feed consumption should increase by 35 % at peak laying period

Feed granular calcium carbonate to:
Improve shell strength
Improve skeletal strength
Prevent excretion of phosphorus
Reduces cage layer fatigue
Cage layer fatigue is caused by weakening of the bones and produces increased incidence in leg fractures.
Granular calcium should be fed before shell formation occurs, i.e. at night.
Water should be free from Salmonella and pathogens
Check quality regularly
Sodium hypochlorite can clean drinking systems (between flocks)
Check residual chlorine levels

Question 11

Enriched or Colony Cages

Answer 11

EU Laying Hens Directive was legislated in 1999 and came into force in 2012 to ban the use of barren (battery) cages

Enriched cages better address the five freedoms:
Potential to nest - cage includes a small nesting area
Potential to roost - perches 7 - 10 cm high
Potential to scratch - a small scratch area is provided with friable matter
Potential to stretch - the height and width of the cage allows for more freedom of movement
Designed to hold up to 90 birds
Enriched cages provide more (shared) space and freedom to perform some natural behaviours (perching, scratching etc)
Still densely stocked (little space for each bird), cannot dust-bathe and the nest ‘box’ is just a curtained area

Typically 40-80 birds, per cage. Hens can recognise up to 90 birds, so will establish a pecking order and then settle with this number of birds kept together.

Cage size - 5 m x 2 m wide (maximum stocking density 9 hens per 1 m2) - 36 % larger than the previous battery cages
Birds lay 98 % of the eggs in the nest box
Hen pecking is reduced whilst egg laying
At night, every bird will have access to sleep on the perch rails
Feeder space - 12 cm
The environment within the chicken shed is carefully controlled:
Clean air moved through the shed
Consistent temperature
Chicken manure is removed two or three times a week from revolving belts underneath the colony, keeping ammonia levels low

Battery cages had a floor area <a></a>

Question 12

Barn Eggs

Answer 12

Maximum stocking density of 9 hens per 1 m2
Hens are provided with perches - 15 cm per hen
Litter floor must account for one-third of the ground surface - scratching and dust bathing
1 nest box per 5 hens (or communal nests)
Barn system hens have the freedom and space to move around, stretch and exercise within a building.

Feeder space - 10 cm per hen (linear feeders) and 4 cm per hen (circular feeders)

Some non-cage housing systems are multi-tier allowing hens to move vertically through the shed

New standards for barn eggs will be enforced from 31st December 2025:
2 enrichments per 1,000 birds
Maximum colony size of 6,000 birds
Superior nest boxes to encourage nesting

Question 13

Free Range Eggs

Answer 13

Similar to barn egg, but sheds have “pop holes”

Continuous access to an outside area during daylight hours (4 m2 per hen) with suitable vegetation and shelter

Half of free-range egg-laying farms use a paddock rotation system – this can increase stocking density above the advised levels

Question 14

Organic Eggs

Answer 14

Always free range
Fed an organically produced diet
Free range pasture must also be organic land
Maximum stocking density of 6 hens per m2
Maximum flock size of 3,000 birds
Hens must be provided with nest boxes, 18 cm of perch space each and at least one-third of the floor be litter-based

Question 15

Egg Use in Vaccine Manufacture

Answer 15

The pharmaceutical sector is a significant market for eggs
Virus needs to replicate within cells
Embryonic eggs are injected with the virus at 10 - 11 days and incubated for a further three days
Viruses replicate and are then harvested from the allantoic fluid (surrounding the embryo)

Eggs are selected from specialised, high-health status farms run for the production of eggs for vaccine manufacture.

Question 16

Broiler Production

Answer 16

In 1945, it took 11 - 12 weeks to get a bird to table weight (2.25 kg)
Today, it takes 35 - 43 days (6 - 7 weeks)
Feed conversion ratio (FCR) is 1.5 - 1.8
Mortality rate <5%
Specialist breeding companies (e.g. Aviagen), producing hybrid birds through the whole supply chain
Breeding programmes for rapid-growing males and fertile females (Breeders).
This rapid weight gain can cause severe health problems, such as lameness and heart defects.

Indoor reared:
Typically house 25,000 - 50,000 birds per house
Available space - maximum total bird weight is restricted to 30 kg/m2, e.g. 19 x 2 kg birds
Temperature, artificial lighting, ventilation, food and water are carefully controlled
Floor covered with wood shavings
Some broiler sheds have curtain sides and/or windows to allow natural light to enter.
Lack of space leads to poor welfare (prevents chickens moving around, causes poor air quality and litter build-up). Causes lameness and skin diseases.
Regulations are different outside of the EU and we can discuss this further in the next lecture.

Question 17

Global Broiler Production

Answer 17

In the early 20th century, chicken was eaten as a treat
In 1950, the UK’s average per capita chicken consumption was <1 kg/year
Today, the UK’s average per capita chicken consumption is 25 kg/year
Developed countriesprefer breasts and thigh meat and, to a lesser extent, drumsticks
Developing countries import cheap, low-quality cuts such as wings, lower legs, necks and giblets
The UK slaughters approximately 20 million broilers per week (1,040 million birds per year).
60% self-sufficient (this has decreased in the last four years from 73%, as the demand for chicken meat has increased)

Question 18

Broiler Production Females

Answer 18

Egg production (breeding replacements)
Slower growing and smaller
At slaughter, go for whole bird production

Question 19

Broiler Production Males

Answer 19

Faster growing
Better FCR
Higher breast meat yield
At slaughter, go for portions

Question 20

Hatchery

Answer 20

UK largest hatchery produces 2.4 million chicks per week
Fertilised eggs are collected from parent flocks on breeding farms and delivered to hatcheries
Eggs incubated for 21 days and the chicks hatch
Chicks moved to farms specialising in raising pullets
Male layers are euthanised with argon and used for feeding reptiles and birds.

Question 21

Broiler Production Improved indoor facilities:

Answer 21

Provision of natural daylight through windows
Reduced stocking densities (12 - 14 birds per m2)
Environmental enrichment, such as straw bales
for the birds to peck at
Slower growing breeds of chicken may be used

Only a small number of production sites use this management method

Question 22

Free range broiler production

Answer 22

Access to an outdoor area of 1 m2 per bird for at least half of their life
Free range chickens slaughtered at 8 weeks old

Question 23

Organic broiler production

Answer 23

Access to an outdoor area of 4 m2 per bird for at least one third of their life
Similar pop holes to free range egg laying hens
Organic chickens slaughtered at 12 weeks old

Question 24

Broiler, Generic Housing Considerations - Lighting

Answer 24

Allow chicks to find water and food quickly (on arrival)
Minimises vices
Initially, continuous bright light for 2 days. Then, decreased light intensity and birds are given ≥ 6 hours dark (4 hours in one dark period)
Minimum lighting level is 20 lux, in contrast to a brightly lit room of 400 lux or natural daylight of 30,000 - 100,000 lux

Light levels can be kept low to encourage the birds to eat more and move around less, which maximises their growth rate.

Question 25

Broiler Generic Housing Considerations - Ventilation

Answer 25

Provide clean, dry fresh air
Remove excess moisture, carbon dioxide (CO2), ammonia (NH3), dust and airborne organisms
Side effect - heat loss

Question 26

Broiler Temperature and Water

Answer 26

Small chicks need to be kept warm on arrival (32 ⁰C), otherwise they will suffer kidney damage and lameness
Temperature is gradually reduced as the chicks grow

Chicks can get dehydrated (0.1 g/hr loss)
On arrival, chicks should be encouraged to drink (dip beaks)
If they do not drink they will not eat

Question 27

Broiler Housing Considerations - Litter

Answer 27

Insulates
Absorbs water
Breaks down faeces
Comfortable
Clean
Minimises dust

Good litter is important as dirty litter can lead to increased disease incidence.

Question 28

Types of litter for broilers

Answer 28

Softwood (hardwood causes splinters in breast)
Good absorption and breakdown
Ensure litter is not contaminated with chemicals or mycotoxins (fungus)
Prevent wild bird access to stored litter (mycoplasma and Salmonella)
Use fresh litter for each crop

Question 29

Ducks

Answer 29

Raised in indoor or outdoor systems
Birds reach finished weight (3.1 - 3.5 kg) around 42 - 56 days old

Over 14 million ducks are raised in the UK each year.

Question 30

Geese

Answer 30

:
Raised in indoor, pole-barns or outdoor systems
Birds reach finished weight of 15 kg (males), but larger birds are raised for Christmas and the pre-process meat markets are finished around 20 weeks of age

Around 300,000 geese are produced each year in the UK.
The top half of the pole-barn wall is made of fencing to let in natural light.
Female geese finishing weight is approximately 9 kg.

Question 31

Turkeys

Answer 31

Between 200,000 - 500,000 birds are slaughtered per week in the UK, depending on the time of the year
Raised in indoor, pole-barns or outdoor systems
Birds reach finished weight of 13 kg, but larger birds are raised for Christmas and the pre-process meat markets are finished around 20 weeks of age
Sheds can hold up to 25,000 birds
Annually the UK produces 15.6 million turkeys.
Most breeding uses AI as the males are now too heavy (too much breast meat).