COMMERCIAL LAYERS MANUAL
COMMERCIAL LAYERS MANUAL
Commercial layer production has the potential of transforming livelihoods of communities, creating generational wealth to farming communities since it provides it's value-chain actors with an opportunity to leverage the big market for it's products and by-products created by the growing population.
This training manual has been designed to bridge the gap of lack of access to, and uptake of appropriate knowledge due to the insufficient investment in agricultural research to provide scientific evidences for sound decision making of farmers to take clear course of action in the production of layers.
Learning objectives.
1. Understand the challenges in commercial layer enterprise and basic steps for a sustainable commercial enterprise.
2. Understand the commercial layer management systems, their merits and demerits.
3. Analyse the production planning process of commercial layer enterprise. Considering site selection, farm layout, features of good commercial poultry house, farm equipments, optimum environment conditions for layers, guiding principles for poultry house management and procedure for disinfection of poultry house.
4. Understand strains production performance goals, sex identification techniques and attributes of a good chick stock.
5. Equip knowledge on the general management practices of layer chicks, pullets and hens to mitigate production risks and enhance profits.
Steps to a sustainable commercial layer enterprise.
Passionately, choose commercial layer enterprise size and strain based on a cost benefit analysis and own capability.
Register the business entity.
Organize adequate finances for operation and fixed costs.
Construct a well designed and equipped poultry structure on a good site location.
Organize and manage a professional competent team (manager, accounts assistant, veterinarian and poultry attendant).
Procure the right quality and quantity of feed.
Cater for good biosecurity, good poultry healthy and welfare.
Market the products well, add value, ensure good quality and categorize your customers according to their credit worthiness.
Plough back at least 80% of the sale revenue to grow the business.
Have a good succession plan.
Challenges in commercial layer enterprise.
Inadequate extension services in the poultry sector.
High level of aflatoxins in poor quality feeds.
Cost of poultry feeds has escalated yet it is not matched by the increase in the price of poultry products.
Existence of many unregulated and unqualified feed manufacturers due to limited enforcement of standards in the sub-sector.
The emergence of many unregistered, unregulated breeding farms.
Lack of feed reserves for feed production during off-season.
The emergence of many unprofessional veterinarians, paraprofessionals and drug sellers.
Inadequate enforcement of quality standards leading to substandard veterinary inputs and equipment on the market.
Increased antibiotics resistance of birds caused by drug abuse.
Over dependence on imports of poultry parent stock from other countries.
Commercial layer management systems.
For commercial layer production management system birds are confined within a house and feed. This is called intensive system characterized by bulky investment capital, high stocking densities, controlled environment, prioritizing efficiency and productivity, often involving large scale operations with specialized facilities and automated systems. Intensive management system for commercial layer enterprise is divided into three categories these include;
i) Deep litter system
ii) Slatted floor system
iii) Battery cage system
i) Deep litter system.
Birds are reared on the concrete floor covered with litter. Litter materials include; coffee husks, saw dust, wood shavings with the ability to absorb moisture and remain quite dry, friable and clean.
Merits of deep litter system.
Ensures good management of layers in large number.
Ensure high production per unit area.
Reduces labour costs.
If well maintained, it is relatively hygienic.
Demerits of deep litter system.
High initial investment costs on buildings, equipments and litter.
High risk of nutritional deficiency since all nutritious feed must be provided.
High risk of Coccidiosis disease.
High risk of internal and external parasites infestation.
Birds develop bad fowl vices.
ii) Slatted floor system.
Similar to deep litter system but no litter used. It has a (0.7) meter raised floor fitted with slats of wood, strong mesh/plastic. The poultry dropping pass through the slates to the ground.
Merits of slatted floor system.
Ensures good management and monitoring of a flock.
Increased production per unit area.
Facilitates easy collection of fowl droppings for manure or fish feed.
Reduces labour costs.
Relatively hygienic with minimal contact of birds with their droppings.
Reduced risk of Coccidiosis infection.
Demerits of slatted floor system.
High investment capital.
High nutritional risks.
Birds develop vices like pecking.
iii) Battery cage system
The birds are confined in cages arranged in tiers, provided with feed and water.
Merits of battery cage system.
Ease management of flocks.
Reduced labour costs
Cleaner and more hygienic system.
Less chance of infection because the birds are not in contact with the droppings.
Increased production per unit area.
Less feed wastage.
Ease monitoring of individual bird.
Controls broodiness in hens.
Demerits of battery cage system
All nutritious feed must be provided.
High equipment and maintenance costs.
Limits exercise hence risk of poor health.
Equipments are specific and not flexible in use.
Associated with more egg damage.
High risk of breakdown of automated equipments.
Production planning of layers.
Successful commercial layer production requires proper planning which involves construction of suitable infrastructures and having enough expansion land. It also enables farmers to avoid biosecurity threats.
Planning starts with selecting an appropriate site, followed by designing a farm layout, followed by designing and construction of poultry houses and other infrastructures, installing biosecurity measures and procuring the right production equipments.
Factors to consider when selecting a layer poultry farm site.
The topography should be relatively flat and well drained.
The land site should be easily accessible but not on a highway.
The location should have good flow of air, far away from tall buildings.
The land site should be far from other poultry, piggery and dairy farms to avoid noise and spread of diseases.
The land site should have a reliable water source.
The land site should have some trees and grass cover for shade and cool the poultry house during hot periods.
Commercial layer farm layout.
A good poultry farm should have the following components.
1. Perimeter chain link
2. Entry gate with a disinfection barrier.
3. Poultry houses
4. Office and Toilets.
5. Changing room and shower facility.
6. Feed and equipment store.
7. Clean water source.
8. Access roads
9. Incinerator/ Sanitary pit.
Construction of a commercial poultry house.
An open sided commercial layer house should be (10 by 25) meters to accommodate (1500)layers with a spacing of 6 bird per m². Designed to meet maximum comfort for birds, convenience for poultry attendants, ease disinfection, simple and cheap to construct.
The length of the entire house should be (27) meters however the effective production hall length is (25) meters. The space deducted is referred to as the operation area (1) meter in-front and (1) meter behind divided into operation units.
A good commercial layer poultry house should have a production hall, changing unit, egg collection unit, isolation unit, double leaf entry and exist door.
The construction of worker's quarters must be outside the perimeter fence inorder to avoid biosecurity threats of diseases from quarters.
Features of a commercial layer poultry house.
A commercial layer house should have a total area of (270)m² subdivided into production hall and operation units which include changing unit, egg collection unit, isolation unit.
Should have a population hall area of (250)m² to accommodate (1500) layers with a spacing of (6) birds/m².
Should have an egg collection unit for easy handling of eggs.
Should have a changing unit with a sink and water tap and detergents to disinfect poultry attendants.
Should have an isolation unit for special care of runts and diseased birds.
Should have double leaf entrance and exist doors to ease management operations.
Should have a breath-roof to enhance natural ventilation in the house due to it's brood width of (10) meters.
Should have a leak-proof roof to protect birds from harsh conditions.
Should have a roof overhang to protect birds splashing rain water and direct sunlight that may penetrate the open sided walls.
Should have strong firm walls to support the roof and withstand strong wind.
Should have open sided wall design, to promote natural ventilation, fitted with wire chicken mesh.
Should have smooth, easy to clean and vermin proof walls.
Should have a concrete moisture proof, easy to clean, vermin proof and durable floor.
Commercial layers house equipments.
Good poultry house equipments should make it convenient for the farmer to use and must provide comfort to the birds at the least possible cost per bird. These equipments include feeders, drinkers, plastic trays, nests, perches, stoves and pots.
Feeders.
These are categorized into linear feeders and tube feeders. A good feeder should be easy to clean, fill with feed, designed to avoid feed spillage and feed contamination by birds.
The space available on the feeder should be enough to allow each bird to access the feed to mitigate competition for feeds and issues of runts and fowl vices.
The recommended space requirements on linear feeder is as follows.
Age (weeks). Space (cm/bird)
0-4. 1.5
5-8. 3.0
9-20. 6.0
<20. 6.0
The recommended space on a tube feeder is 4cm/bird.
Drinkers.
These include; round drinkers, drinking nipples and drinking cups.
Round drinkers ensure ready availability of water and suspension height is easy to adjust but it is an open system with high chances of water contamination and water spillage.
Drinking nipples is a closed system, water is always fresh, with little spillage and doesn't occupy much space hence giving more room for the birds and attendants though expensive and water dispensing is harder to control.
Drinking cups ensure ready availability of water, easy to check for blockages though expensive with high chances of water contamination.
A good drinker should keep water clean an cool, easy to clean. It better to have drinkers raised above the floor to prevent water contamination with litter and fowl droppings.
Allow at least 2cm of linear watering space per chick and 5cm per adult layer, (10-13) bell-shaped 35cm diameter per 100 layers, (1) nipple drinker for (8-10) layers.
The recommended water intake capacity in litres per 50 chicks with age is as follows.
Age (weeks). Water capacity(litres)
0-2. 4
2-4. 8
Perches/ hen roosters.
These are wooden bars running across the room on which hens roost when they are not feeding. Layers are light in weight and normally like jumping onto objects. This keeps them occupied and minimize the risk of bad fowl vices. Allow (15-25)cm of percher space for each bird. Perches can be fit in-front of decked nest boxes with a diameter of (5)cm raised above (60)cm from the ground.
Nests.
These are necessary equipment in the production hall categorized into individual nests and communal nests.
Individual nests are (0.05)m², arranged in (3-5) decks have been proved to be beneficial in deep litter houses where no perches are provided. A piece of wood is fitted in-front of each deck to allow the hen perch before she enters the nest. The nests are kept open and clean litter is provided in each nest. Allow (5-6) hens per nest.
A communal nests is a box (1.8 by 0.6) meters, with no partitions. Allow (1)m² per (100) birds in the case of communal nests. The nest may be placed against the wall and the front is covered with pieces of old sacks to allow birds enter and leave the nest with easy.
It is important to allow adequate nest space because accumulation of eggs in the nest results in eg breakage and dirty eggs. Also more eggs will be laid on the floor if there is insufficient nest / nest space. Eggs may be collected (2-4) times a day depending on the intensity of laying to mitigate risk egg eating and dirty eggs.
Optimum environmental conditions in poultry house.
For layers to perform at it's maximum potential it must be comfortable and free from stressful conditions. A good poultry house should protect the birds from extreme temperatures, humidity, winds, rain and other unfavorable conditions.
Temperature.
During the first week of brooding, room temperature should be about 35⁰C and reduced by 3⁰C per week until the chicks have sufficient feathers for a period of (4) weeks.
Humidity
In a poultry house, relative humidity should be below 75% and the moisture content of litter, below 30%. High humidity in the poultry house can cause serious health hazzards leading to death of birds. These include; respiratory disorders and diseases, high ammonia content and it's heath risks, increased reproduction of disease causing micro-organisms. Therefore the need to ensure adequate ventilation to allow the prevailing wind into the house and regulate house humidity content.
House ventilation.
Movement of fresh air through the house is essential to allow in oxygen needed for respiration and remove the carbon dioxide, water vapor and ammonia in the poultry house.
Poor ventilation leads to accumulation of ammonia in the poultry house hence depressing the birds appetite, reduced growth rates, increased susceptibility to respiratory problems, blindness of birds and development of Ascites.
Light
Light duration is essential in layers, pullets will not start laying unless they receive (12-13) hours of light per day.
Increasing day light length during the growing period (6-18) weeks of age will lead to release of Follicle stimulating hormone and luteinizing hormone which cause rapid development of ovary and oviduct, subsequently initiating egg production.
Light wave length visible on the spectrum by man (4,000-7,000) Angstroms have a stimulating effect on the reproductive system of both hens and cocks. Birds don't respond well to dim light / blue-green light.
Guiding principles for poultry house management.
Should have a footbath filled with disinfectant solution at the entrance doors of every poultry house.
Dead birds must be disposed off immediately by either burning or burying.
Keep unnecessary visitors away from the poultry house. These are potential sources of infectious diseases.
Adapt an all in-all out programme, Don't mix stocks.
Ensure to keep litter clean, soft friable by regular turning using shovel and a rake to enhance litter's ability to absorb moisture.
Ensure a leak-proof roof by repairing and replacing old roof.
Ensure a vermin proof house by blocking any holes and cracks to eradicate entry of rodents hence mitigating risk of feed wastage, transmission of disease and external parasites infestation.
Clean and disinfect the poultry house before stocking.
Cleaning and disinfection of poultry house.
The main aim of cleaning and disinfection of poultry house is to keep the level of disease causing micro-organisms as low as possible.
Chemical disinfection is the most effective method of disinfection. The chemical agents in these disinfectants include Phenols, alcohol, acids, salts of heavy metals and hypochlorite. Example of common disinfectant is Bio-safe.
Procedure for disinfection of poultry house.
Remove all the birds, if the house has been in use.
Remove all the feeders and drinkers, clean them thoroughly with detergent and dry them in the sun.
Remove all the litter from the poultry house.
Soak the floor and walls with plenty of water to ensure thoroughly wetting.
Scrub and wash down all dirt using detergent, then rinse the room and allow it to dry.
Apply the disinfectant carefully following the manufacturers instruction.
Leave the house to rest for at least 2 weeks before setting in another stock of birds.
Layer strains
For commercial layer production, at the hatchery eggs which are incubated hatch both male and female chicks. Soon after hatching male chicks are removed and killed, leaving only female chicks.
Layers are usually developed from sex-link crossing involving Rhode Island Red males with Australorp and White leghorn female. Breeders don't reveal the details of the crosses but rather they assign a name to each strain.
Examples of layer strains include Isa Brown, Goldline, Tegel super brown, NERA- sex-link, Sykes H³, and several others. Farmers should therefore obtain information about the expected performance of a given selected strain from chick suppliers because each strain has unique growth and production characteristics.
Sex identification techniques used at hatcheries.
1. Colour sexing.
This is the most common used sex identification technique, effective for specific breeds.
Some breeds of chicken exhibit colour difference between male and female chicks at a very young age.
Using sex-link crossing principles (hybrid chicken breeds). Mating Rhode Island Red males with Rhode Island White females. Their offspring will consist of yellow/white coloured day old male chicks and brown coloured day old female chicks hence easy sorting of chicks.
The most common sex-link crossed are the red sex link. Close to half of the global layer population consist of red sex link chicken. Our common brown breeds ( Isa Brown, Hi sex Brown).
2. Vent sexing.
Involves carefully holding the chick upside down, squeezing out fecal matter and then turning outward the vent area (Cloaca) for visual inspection of a small bump/ phallus which indicates a male chick.
A trained person can identify the presence or absence of the phallus and vent sexing can be stressful for the chicks, so it's best to use as a last resort.
Performance production goals of layer strains.
Sexual age maturity of about (18-20) weeks.
Low mortality rate of (3-5)% from (20-80) weeks of age.
A peak production of (90-95)%.
An average egg weight of about (56)g.
(300-320) total number of eggs each bird from (20-80) weeks of age.
Feed efficiency during laying of about 2.3
Body weight of (1.8-2.2)kg at (80)weeks of age.
Attributes of a good layer chick stock.
It's important to start with high quality, health, chick stock, therefore the need to cross check an make sure you are buying good quality chicks to mitigate risk of high chick mortality rate and increased production cost on health and disease management. The following are the attributes of a good layer chick stock.
Chicks should be active with a quick reflex to stand up when laid on their backs with in a period of (3) seconds.
Chicks should have clean, open and bright eyes.
Chicks should have closed navel.
Chicks should have normal uniform coloured, bright feet.
Chicks should have clean beak and nostrils.
Chicks should be of uniform size.
Should have a body temperature of about (40-40.8)⁰C.
Brooder Management.
A brooder is a special room designed to provide optimal conditions for the growth and development of day old chicks in the first four weeks of the chicks life.
The first two weeks of a chicks life are the most important in the development process of the chick as mistakes made at this time cannot be corrected later. It is during this period that maximum growth is attained and development of all internal organs and skeleton takes place. The brooder is therefore the foundation of layers enterprise and should be properly managed for high performance.
A good brooder house should ensure proper house ventilation, optimum light, adequate spacing adjustable with time and optimum temperature of 35⁰C at the initial week of brooding, later dropped by 3⁰C for a period 4 weeks.
Key points to consider in brooder management.
Carryout a complete farm clean out and disinfection program before introducing chicks.
Determine the brooding space by the number of chicks, normally ranging between (30-40) chicks per m².
Spread evenly the litter on the concrete floor at the depth of (10-15)cm.
Spread newspaper on top of the litter to mitigate risk of chocking. Sprinkle feeds on top of the newspaper.
Provide optimum and evenly distributed light, by using kerosene lamps/electric bulbs raised about (40)cm above the ground.
Pre-heat the house at least (24-48)hours before stocking
Minimum ventilation should be started as soon as pre-heating begins to remove waste gases and condensation. Seal leaks and cracks to prevent draft and maximize air flow.
High quality thermometers should be suspended just above the litter at key points to effectively record the room temperature.
Arrange the drinkers and feeders in an orderly manner, alternating the lines of drinkers with the feeders.
Set the appropriate drinker system height to allow chicks access water usually, at chick eye height.
Ensure there are no airlocks in the pipes and that each nipple has a droplet of water present. Bell-shaped drinkers should be suspended with the base just above the litter.
Provide quality water from a clean source using appropriate drinkers for the age of birds as water intake increases with age.
Supplementary drinkers should be filled with lukewarm water mixed with chick formula and glucose. Add (3-4) drops of cooking oil/paraffin on every font drinker after every (2) hours for the first three days to prevent constipation.
After (2)hours of stocking, check the chicks to ensure that they are comfortable with the temperature by observing the chick behavior and thermometer measures.
Fill the feeders with crumble/mesh ration of the right size from a reliable source after (2)hours of stocking.
Additional feeding space should be provided for the first week on feed trays/box material for maximum consumption. Feed trays are provided at the rate of (1)tray per 100 chicks. (65)grams of feed per chick should be provided on the additional feeders.
The crops of chicks should be checked in the morning after the stocking date to ensure that the chicks have found both food and water. The crop should feel soft and pliable and minimum of 95% of the chicks should be filled.
Management of Immature Pullets.
The main objective of proper management of immature pullets from (4-8)weeks of age is to produce healthy, vaccinated pullets, well adapted to conditions which they will be exposed to during laying period.
Management of pullets has major influence on the sexual maturity age, maturity weight as well as on subsequent laying performance. Body weight is the major criterion used in assessing pullet growth in comparison with the bird's growth rate with that which is recommended by the breeder.
Management practices focuses on ensuring optimum stocking rate, house environment conditions, vaccination and disease control, debeaking, litter management, feeding, record keeping and transfer of pullets to the laying pens/house.
Stocking rate and house conditions.
Allow (6-10) pullets per m² in the rearing pens. Place perches in the house. Perches enable birds to exercise and prevent boredom which would lead fowl vices.
Ensure (12-13) hours of day light to facilitate normal growth of pullets. In the tropical region there is normal natural day light of about (12-13)hours throughout the year. Day light length has an influence on the stimulation of birds to reach sexual maturity. Pullets will not start laying unless they receive at least (12) hours of day light.
During this pullet rearing period, don't light the poultry house during the night. Exposing pullets to longer hours of light will cause pullets to start laying eggs when they are immature hence laying very small eggs at the beginning and their laying cycle will be shorter by about (20)weeks, thus each hen will lay fewer eggs than expected.
Vaccination schedule and disease control.
Vaccination should be administered according to breeder's recommendation update information about diseases to be vaccinated against and vaccination schedules are usually obtained from local veterinary officers.
Examples of such diseases include Marek's disease, Newcastle disease, Gumboro disease, Fowl typhoid, Fowl pox, Infectious bronchitis, Avian encephalomalacia and Infectious laryngotracheitis.
De-becking.
Also called beak trimming, a process of partial removal of the beak of a poultry bird. It is a good management practice to prevent and control poultry vices. Also reduce feed wastage in layers.
Beak trimming must be done carefully because poor beak trimming causes excessive bleeding and makes feeding and drinking difficult.
Precautions for de-becking.
Ensure a good healthy status of the flock.
Don't beak trim birds soon after vaccination. Birds need at least a week to recover from the stress.
Add Vitamin K to the drinking water before de-becking to reduce excessive bleeding (haemorrhage) at the time of de-becking.
The temperature of the cutting blade must be high enough (red hot) to give adequate cauterization without damaging the beak.
Add Vitamins to the drinking after de-becking to reduce the effect of stress.
Ensure the level of feed and water is increased, allowing one week of full feeding to ease feeding as well as reduce stress.
When and How to beak trim.
Beak trimming is best done at age (10-14)days. At this age there is less stress and it is easy to handle the birds when they are small. The cut should be at least (2)mm from the nostril, this possible with beak trimmer.
In absence of proper beak trimmers, beak trimming can be done at later age, properly after 10 weeks of age. In Uganda, the vaccination schedule is very tight hence this doesn't leave any space for de-becking in the first ten weeks of the birds life. This is why de-becking is often done when pullets are (14 and 17) weeks of age.
Feeding
The feeding program of the pullets should aim at achieving the target growth curve recommended by the breeders for the particular strain. If the maturity body weight is very low, layers will have a poor peak rate of egg production or a rapid drop in egg production after the peak. Ontheotherhand if the pullets are too heavy at the maturity age, undesirable reproduction complications may occur leading to poor egg production.
Feeding of pullets should aim at meeting the daily nutrient requirements without making the birds come into laying when immature or when carrying too much fat. To achieve this "controlled feeding" is practiced.
During controlled feeding a lower nutrient density. The conventional grower diet containing 2700kcal/kg, 16% crude protein, 1.1% Calcium, 0.4% Phosphorus and 0.6%Lysine is provided from (9-18)weeks of age. Alternatively, practicing restricted feeding where birds are provided with a limited amount of feed on a daily basis.
Record keeping.
Records of feed intake, body weight and mortality are essential to analyze the production effectiveness of a selected strain.
All the feed which is offered to birds must be recorded. At monthly intervals calculate the amount each bird would have consumed in a month.
Compute the body weight random mean of a selected sample.
Calculate the feed conversion rate and record the mortality rate.
All health problems should be recorded as they occur.
Litter management
If the flock is kept under the deep litter system, the litter must be maintained in friable state by regular turning and raking using a shovel and rake.
Avoid water spillage which is bound to make the litter wet and mouldy.
Repair/replace old leaking roof to mitigate wet or mould litter that can lead to Aspergillosis.
Transfer of pullets to the laying pen.
Pullets are transfered to laying pen/battery cages at (18)weeks of age. The layer's house should be equipped with laying nest and perches before they are placed into the room to avoid panic and stress.
The amount of stress during transfer can be reduced by gentle and careful handling and transferring the birds in crates instead of holding them by wings/feet.
Feeding laying hens.
Commercial layers should be fed to appetite on a well balanced diet in all nutrients " layer mesh" composed of 2900kcal/kg, 17% crude protein, (3-4)% Calcium, 0.4% phosphorus, 0.3% Methionine, 0.6 Lysine.
Shortage of Calcium in the diet will lead to poor egg production.
Hens should be provided with clean drinking water at all times to prevent gut infections. Insufficient provision of water will lead hens to stop laying and force birds to pre-mature moulting.
Layers production records.
Commercial layer production enterprise is only a meaningful business venture when records are kept and analyzed. Keeping production records is good but if they are not analyzed it is wasted efforts.
Analysis and interpretation of records helps to detect errors, and problems promptly. It also helps to improve subsequent performance of the farm units.
Examples of layer records include egg production records, feed intake records, monthly head count, egg weight, body weight and mortality records.
i) Egg production records.
To prevent an accumulation of eggs in the production hall, eggs should be collected at least (2)times in a day and recorded in an organized record book.
ii) Feed Intake.
On a daily basis, record the weight of the feed you provide in each production hall. At the end of the month calculate the mean daily feed intake per hen. This will show you if hens are consuming the recommended amount of feed.
Underfeeding and over feeding have implications on the flocks efficiency of egg production.
iii) Monthly head count.
Once a month, take time and count the birds present in each production hall. This helps to confirm records taken and check possible theft of birds.
iv) Egg weight
This is recorded once a month. A random sample of eggs is picked and weighed on 3 consecutive days of the last week of the month.
v) Body weight.
It is advisable to monitor body weight of the layers. This will serve as an indicator of their nutritional and health status. Take the weight of a sample of hens from the production hall and record the mean weight. Compare this with the recommended weight of the strain at that particular age.
vi) Mortalities.
If any death occurs it should be recorded immediately. Also take note of the cause of the death and measures used.
A good laying flock possible production records.
The following are the good production records of a good laying flock.
Age at first egg (135-147) days.
Body weight at maturity age (1.4-1.6)kg.
Survival rate of (20-80) weeks of age ranging between (92-95)%
Average number of eggs per bird of 320 eggs
Mean egg weight of (59)g
Feed consumption rate of (100-120)grams per hen per day.
Feed efficiency of (2.4-2.5)
Body weight of (1.8-2.4)kg at (80)weeks of age.
Egg formation process.
To appreciate all the egg features and quality. It's essential to know how an egg is formed in the hens reproductive system.
The reproductive system of a hen is composed of one ovary and oviduct. When the hen is laying eggs, it's reproductive system is enlarged. The ovary is big with varying size of ovarian follicles and the oviduct appears like a large and thick coil in the abdomen. Blood supply to the reproductive system is increased so as to deliver raw materials for egg formation.
On a daily basis, a mature ovarian follicles raptured and releases it's content into the infundibulum. This is called "ovulation". The content of the ovarian follicle comprise of the yolk and germinal disc. Normally no bleeding occurs during ovulation because rapture occurs along a blood capillaries free zone called "stigma".
If the hen is breeding, spermatozoa will be present in the "infundibulum" and fertilization will takeplace. However in the absence of spermatozoa an infertile egg is formed. The follicle content (yolk and germinal disc) spend (4) minutes in the infundibulum and proceeds to the Magnum.
The Magnum region is where the albumen is deposited.Chalaza formation involves the twisting of albumen fibers, anchored at opposite ends of the egg yolk, as the egg rotates and descends in the oviduct, ultimately forming the spiral bands that suspend the yolk in the center of the egg white. The egg content spends (4)hours in the Magnum as the albumen is deposited before moving to the "Isthmus" region.
In the Isthmus region the inner and outer membrane are deposited around the egg materials. The egg content spends (1)hour and (15) minutes in the Isthmus as the outer and inner membrane are deposited before moving to the uterus.
The egg spends about (20)hours in the uterus as the shell is deposited carefully around the egg. Egg shell deposition requires a lot of calcium.
Finally when formation of the egg is complete the hen push the egg through the vent a process known as "laying". The hen makes sure that the egg is not contaminated with faecal matter, so at the time of laying the egg is clean and wholesome.
13 Key nutritional benefits of eating Eggs.
1. High-Quality Protein:
Eggs are a complete protein source,
meaning they contain all nine essential amino acids that the body needs but cannot produce on its own.
2. Vitamin A:
Eggs, especially the yolk, are a good source of vitamin A, which is important for vision, immune function, and healthy skin.
3. Vitamin B12:
Eggs are a good source of vitamin B12, which is essential for nerve function and the formation of red blood cells.
4. Vitamin D:
Eggs are a good source of vitamin D, which is important for bone health, immune function, and overall well-being.
5. Choline:
Eggs are an excellent source of choline, a nutrient that supports brain function and metabolism.
6. Selenium:
Eggs are a good source of selenium, an antioxidant that helps protect cells from damage.
7. Phosphorus:
Eggs contain phosphorus, which is important for bone health and energy production.
8. Folate:
Eggs contain folate, a B vitamin that is important for cell growth and development.
9. Riboflavin:
Eggs are a good source of riboflavin (vitamin B2), which is important for energy production and cell growth.
10. Healthy Fats:
Eggs contain healthy fats, including monounsaturated and polyunsaturated fats, which are beneficial for heart health.
11. Lutein and Zeaxanthin:
The yolk contains lutein and zeaxanthin, antioxidants that are beneficial for eye health.
12. Pantothenic Acid (Vitamin B5):
Eggs contain pantothenic acid, which is important for converting food into energy and breaking down fats.
13. Vitamin E:
Eggs are a good source of vitamin E, which is an antioxidant that helps protect cells from damage.
Practices for production clean wholesome eggs.
Maintain clean litter and nest.
Collect eggs as soon as possible after they have been laid (2-4)times a day.
Use clean baskets for egg collection.
Sort and candle eggs to remove those with defects for example double yolked, cracked and those with blood stain.
Pack eggs in clean egg trays, with the broad end facing up.
Store eggs in a cool store(15)⁰C with relative humidity of (75-80)% to prevent desiccation.
Avoid prolonged storage of eggs to maintain egg quality prior 7 days.
Effects of prolonged storage of eggs.
Deterioration of eggs is a time and temperature dependant process. Prolonged storage, especially under warm room temperature results into the following.
Loss of moisture from the eggs, hence adherence of egg contents to the shell.
Loss of carbon dioxide, hence increase in the pH of albumen from (7.6-8.2) to upto 9.5.
Increase in air cell size.
Watery albumen ( the albumen loses viscosity)
The yolk absorbs moisture from the albumen, swells up and subsequently it raptures.
Methods to determine egg quality.
Assessment of egg quality is based on the following criteria.
1. External appearance
2. Candling
3. Internal appearance
1. External appearance
Size - Egg size is generally dependant on age and breed. Young hens lay relatively small eggs and size tends to increase with age. However adult hen could lay an undersized egg of less than (30)g, such an egg is abnormal and called "yolkless egg". Abnormal big double yolked eggs can also be laid.
Shape - The normal shape of chicken egg is an oval shape any other shapes are considered abnormal.
Shell texture - A normal chicken egg should have smooth and uniformly deposited shell. Rough texture may be a sign of infectious bronchitis.
Wholesome - A normal egg is wholesome. Cracked and soft shelled eggs are considered to be abnormal eggs.
2. Candling
Candling is used to determine some characteristics of the internal parts of the egg without breaking the egg open.
This involves viewing an egg against a strong beam of light. By this method you can detect the smallest shell crack. In addition, if there are blood spots, double yolks they are observed as dark spots with the aid of an "egg candler".
3. Internal appearance.
Internal appearance characteristics are detected by breaking the egg open to assess the odour and freshness of the egg contents. A foul smell indicate that the egg is stale.
Used also to assess the yolk colour and firmness of the albumen.
Common problem in layers house.
1. Vices.
Among the behavior characteristics of hens is fighting each other, weak and prolapsed birds are victims for serious injuries as results of pecking and cannibalism this can be controlled by de-becking.
Cannibalism vice is encouraged by deficiency of amino acids and over crowding.
Egg eating may develop if any hen lays soft eggs. This happen when there is calcium nutritional deficiency. Controlled by provision adequate calcium in the poultry feed whereas ensuring nest are set in dark corners of the production hall.
Open communal nests encourage vent pecking vice as well as egg eating vice mitigated by provision of individual deck nests.
2. Broodiness.
Broodiness is undesirable trait in the commercial egg production. A broody hen, apart from being unproductive it will also stay in the nest and may cause egg breakages. Such hen must be identified and culled earlier, isolated in a wire mesh cage until she losses broodiness.
3. Infertility.
Due to either illness/ infertility or both some hens may fail to lay eggs. Some hen, may get into the habit of laying abnormal eggs, such hen must be identified earlier and culled. Hens with small, dry vents and narrow pubic bone may be unproductive and should culled
4. Incidence of abnormal eggs.
Pullets in their first two months of egg production are likely to lay a considerable number of double yolked eggs, shell-less eggs and soft shelled eggs. The situation normalize with time. After (35) weeks of age, there may be a few cases of yolkless eggs. The farmer usually has no control over such occurance .
Grading of eggs can be a suitable opportunity to fetch significant profit on double yolked eggs.
5. Moulting.
If layers are not provided with drinking water for a day/two they will stop laying and moult pre-maturely. Pre-mature moulting is undesirable since the hen will cease to lay when they moult. Egg production normally resumes after the hen has grown a new set of feathers.
6. Fright.
Layers have a tendency to be nervous. They are sensitive to strangers, strange noise, objects and movements, change in feed quality and so on.
When layers sense such strange things they get frightened and stop laying eggs. They usually resume laying after a short period time. Hence the need to protect layers from things that frighten them.
7. Internal and external parasites.
These lead to discomfort and loss of blood resulting to low feed in-take, Anemia and reduce feed conversion rate hence affecting productive in layers.
If layers are infested with internal worm, dose them with appropriate deworming drugs such as Piperazine, Albendazole and fenbendazole. Make efforts to prevent external parasites by proper litter management, using good bio-security measures. Control external parasites by spraying the house with acaricide for mites and insecticides for flies.
In conclusion.
Commercial layer enterprise is an economic transformation venture. With access and uptake of appropriate knowledge and innovation with scientific evidences to guide farmers to take clear course of action in the production of layers, is essential for sustainable commercial layer production.
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