Poultry Production Flashcards
The Domestication History of Chickens
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.
Expansion of the Poultry Industry
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.
Main types of poultry production include:
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)).
Development of Laying Hen
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
Laying Hens
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)
The Global Perspective
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.
Egg Production
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 %
Rearing Laying Hens
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.
Laying hen Transfer to Laying Site
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.
Generic Housing Considerations
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
Enriched or Colony Cages
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>
Barn Eggs
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
Free Range Eggs
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
Organic Eggs
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
Egg Use in Vaccine Manufacture
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.