There are four main types of disease affecting poultry: metabolic and nutritional diseases; infectious diseases; parasitic diseases; and behavioural diseases.
Metabolic and nutritional diseases
These are conditions caused by a disturbance of normal metabolic functions either through a genetic defect, inadequate or inappropriate nutrition or impaired nutrient utilisation. These include Fatty Liver Syndrome, Perosis (or slipped tendon), Rickets and Cage Layer Fatigue.
An infectious disease is any disease caused by invasion of a host by a pathogen which subsequently grows and multiplies in the body. Infectious diseases are often contagious, which means they can be spread directly or indirectly from one living thing to another. These include Avian Encephalomyelitis, Avian Influenza, Avian Tuberculosis, Chicken Anaemia Virus Infection (or CAV), Chlamydiosis, Egg Drop Syndrome (or EDS), Fowl Cholera (or Pasteurellosis), Fowl Pox, Infectious Bronchitis, Infectious Bursal Disease (or Gumboro), Infectious Coryza, Infectious Laryngotracheitis, Lymphoid Leukosis, Marek’s Disease, Mycoplasmosis, Necrotic Enteritis, Newcastle Disease and Salmonellosis.
Parasitic diseases are infections or infestations with parasitic organisms. They are often contracted through contact with an intermediate vector, but may occur as the result of direct exposure. A parasite is an organism that lives in or on, and takes its nourishment from, another organism. A parasite cannot live independently. These include Coccidiosis, Cryptosporidiosis, Histomoniasis, Lice and Mites, Parasitic Worms (or Helminths), Toxoplasmosis and Trichomoniasis.
Abnormal behavioural patterns can lead to injury or ill health of the abnormally behaving bird and/or its companions. These include Cannibalism (or aggressive pecking).
Diseases caused by Viruses
Big Liver and Spleen Disease
Chicken Anaemia Virus Infection (or CAV)
Egg drop syndrome (or EDS)
Inclusion Body Hepatitis (or Fowl adenovirus type 8 )
Infectious Bursal Disease (or Gumboro)
Lympoid Tumour Disease (Reticuloendotheliosis)
Marek’s Disease Virus or MDV
Runting/stunting and malabsorption syndromes
Viral Arthritis (Tenosynovitis)
Diseases caused by Chlamydia
Diseases caused by Mycoplasmas
Mycoplasmosis – MG (Mycoplasma gallisepticum; MG infection; Chronic Respiratory Disease)
Mycoplasmosis – MS (Mycoplasma synoviae; infectious synovitis)
Diseases caused by Bacteria
Fowl Cholera (or pasteurellosis)
Spirochaetosis (Avian Intestinal Spirochaetosis)
Tuberculosis (Avian Tuberculosis)
Diseases caused by Fungi
Moniliasis (Candidiasis; crop mycosis)
Diseases caused by Protozoa
Diseases caused by Internal Parasites
Diseases caused by External Parasites
Several types of louse (insect; plural – lice)
Stickfast flea (insect)
Several types of mite (acarid)
Diseases caused by Metabolic Disorders
Cage Layer Fatigue and Rickets
Fatty Liver Haemorrhagic Syndrome
Diseases caused by environmental factors
Cannibalism (or aggressive pecking)
The principles of poultry husbandry
There are a number of requirements by which animals should be managed so that the best performance is achieved in a way acceptable to those responsible for the care of the animals and to the community generally. These requirements are the keys to good management and may be used to test the management of a poultry enterprise in relation to the standard of its management. These requirements are also called Principles.
The importance of each Principle changes with the situation and thus the emphasis placed on each may alter from place to place and from time to time. This means that, while the Principles do not change, the degree of emphasis and method of application may change. Every facet of the poultry operation should be tested against the relevant principle(s). The Principles of Poultry Husbandry are:
The quality and class of stock
If the enterprise is to be successful it is necessary to use stock known to be of good quality and of the appropriate genotype for the commodity to be produced in the management situation to be used. The obvious first decision is to choose meat type for meat production and an egg type for egg production. However, having made that decision, it is then necessary to analyse the management situation and market to select a genotype that suits the management situation and/or produces a commodity suitable for that market. A good example is that of brown eggshells. If the market requires eggs to have brown shells, the genotype selected must be a brown shell layer. Another example would be to choose a genotype best suited for use in a tropical environment. The manager must know in detail the requirements of the situation and then select a genotype best suited to that situation.
The following are of major importance when considering the health, welfare and husbandry requirements for a flock:
Confine the birds
- Confining the birds provides a number of advantages:
- Provides a degree of protection from predators
- Reduces the labour costs in the management of the birds
- Increases the number of birds that can be maintained by the same labour force
- Reduces the costs of production
- Better organisation of the stocking program
- Better organisation management to suit the type and age of the birds housed
- Importantly, the confinement of the birds at higher stocking densities has a number of disadvantages also including:
- Increases the risk of infectious disease passing from one bird to another
- Increases the probability that undesirable behavioural changes may occur
- Increases the probability of a significant drop in performance
- Birds housed at very high densities can often attract adverse comments
Protection from a harsh environment
A harsh environment is defined as the one that is outside of the comfort range of the birds. In this context high and low temperature, high humidity in some circumstances, excessively strong wind, inadequate ventilation and/or air movement and high levels of harmful air pollutants such as ammonia are examples of a harsh environment. Much effort is made in designing and building poultry houses that will permit the regulation of the environment to a significant degree.
It is the responsibility of those in charge, and responsible for, the day-to-day management of the birds that the environment control systems are operated as efficiently as possible. To this end, those responsible require a good knowledge of the different factors that constitute the environment and how they interact with each other to produce the actual conditions in the house and, more importantly, what can be done to improve the house environment.
A successful poultry house has to satisfy the welfare needs of the birds which vary with the class, age and housing system. Failure to satisfy these needs will, in many cases, result in lower performance from the birds. These needs include:
- The provision of adequate floor space with enough headroom
- The provision of good quality food with adequate feeding space
- The provision of good quality water with adequate drinking space
- The opportunity to associate with flock mates
- The elimination of anything that may cause injury
- The elimination of all sources of unnecessary harassment
The maintenance of good health
The presence of disease in the poultry flock is reflected by inferior performance. It is essential that the flock is in good health to achieve their performance potential. There are three elements of good health management of a poultry flock. These are:
The prevention of disease
The early recognition of disease
The early treatment of disease
Prevention of disease
Preventing the birds from disease is a much more economical way of health management than waiting for the flock to become diseased before taking appropriate action. There are a number of factors that are significant in disease prevention. These are:
1. Application of astringent farm quarantine program:
- The isolation of the farm/sheds from all other poultry.
- The control of vehicles and visitors.
- The introduction of day-old chicks only onto the farm.
- The prevention of access to the sheds by all wild birds and all other animals including vermin.
- The provision of shower facilities and clean clothing for staff and visitors.
- The control of the movement of staff and equipment around the farm.
2. The use of good hygiene practices:
- The provision of wash facilities for staff, essential visitors and vehicles prior to entry.
- The use of disinfectant foot baths at the entry to each shed.
- The thorough cleaning and disinfection of all sheds between flocks.
- Maintaining the flock in a good state of well being by good stockmanship, nutrition and housing.
The use of a suitable vaccination program.
The use of a preventive medication program.
The use of monitoring procedures to keep a check on the disease organism status of the farm, to check on the effectiveness of cleaning and sanitation procedures and to test the immunity levels to certain diseases in the stock to check the effectiveness of the vaccination program.
The early recognition of disease
Early recognition of disease is one of the first skills that should be learned by the poultry flock manager. Frequent inspection of the flock to monitor for signs of sickness are required. It is expected that inspection of all the birds is the first task performed each day, to monitor for signs of ill health, injury and harassment. At the same time feeders, drinkers and other equipment can be checked for serviceability. If a problem has developed since the last inspection, appropriate action can be taken in a timely manner.
The early treatment of disease
If a disease should infect a flock, early treatment may mean the difference between a mild outbreak and a more serious one. It is important that the correct treatment be used as soon as possible. This can only be achieved when the correct diagnosis has been made at an early stage. While there are times when appropriate treatment can be recommended as a result of a field diagnosis i.e. a farm autopsy, it is best if all such diagnoses be supported by a laboratory examination to confirm the field diagnosis as well as to ensure that other conditions are not also involved. When treating stock, it is important that the treatment be administered correctly and at the recommended concentration or dose rate. Always read the instructions carefully and follow them. Most treatments should be administered under the guidance of the regular flock veterinarian.
Nutrition for economic performance
Diets may be formulated for each class of stock under various conditions of management, environment and production level. The diet specification to be used to obtain economic performance in any given situation will depend on the factors such as:
The cost of the mixed diet
The commodity prices i.e. the income
The availability, price and quality of the different ingredients
- Maximising production is not necessarily the most profitable strategy to use as the additional cost required to provide the diet that will give maximum production may be greater than the value of the increase in production gained. A lower quality diet, while resulting in lower production may bring in greatest profit in the long term because of the significantly lower feed costs. Also the food given to a flock must be appropriate for that class of stock – good quality feed for one class of bird will quite likely be unsuitable for another.
- The following are key aspects in relation to the provision of a quality diet:
- The ingredients from which the diet is made must be of good quality.
- The weighing or measuring of all the ingredients must be accurate.
All of the specified ingredients must be included. If one e.g. a grain is unavailable, the diet should be re-formulated. One ingredient is not usually a substitute for another without re-formulation.
The micro-ingredients such as the amino acids, vitamins, minerals and other similar materials should not be too old and should be stored in cool storage – many such ingredients lose their potency over time, and particularly so at high temperatures.
Do not use mouldy ingredients – these should be discarded. Mould in poultry food may contain toxins that may affect the birds.
Do not use feed that is too old or has become mouldy. Storage facilities such as silos should be cleaned frequently to prevent the accumulation of mouldy material.
The practice of good stockpersonship
The term “stockpersonship” is difficult to define because it often means different things to different people. However, “stockpersonship” may be defined as ‘the harmonious interaction between the stock and the person responsible for their daily care’. There is no doubt that some stock people are able to obtain much better performance than others, under identical conditions. The basis of good stockpersonship is having a positive attitude and knowledge of the needs and behaviour of the stock under different circumstances, of management techniques and a willingness to spend time with the stock to be able to react to any adverse situations as they develop to keep stress to a minimum. Having the right attitude is also a very important element. The stockperson who spends as much time as possible with the stock from day old onward by moving among them, handling them and talking to them, will grow a much quieter bird that reacts less to harassment, is more resistant to disease and performs better.
The maximum use of management techniques
There are a number of different management techniques available for use by stockpersons that, while not essential for the welfare of the stock, do result in better performance. Examples of these are the regulation of day length, the management of live weight for age and of flock uniformity. The good manager will utilise these techniques whenever possible to maximise production efficiency and hence profitability of the flock.
The use of records
There are two types of records that need be kept on a poultry enterprise:
Those required for financial management – for business and taxation reasons
Those required for the efficient physical management of the enterprise
For records to be of use in the management of the enterprise, they must be complete, current and accurate, be analysed and then used in the decision making process. Failure to use them means that all of the effort to gather the information will have been wasted and performance not monitored. As a result, many problems that could have been fixed before they cause irreparable harm may not be identified until too late.
There are three important elements to good marketing practice:
Produce the commodity required by the consumer – this usually means continuous market research must be carried out to relate production to demand.
Be competitive – higher price is usually associated with good quality and/or specialised product. Therefore, it is necessary to relate price to quality and market demand and to operate in a competitive manner with the opposition.
Reliability – produce a commodity for the market and ensure that supply, price and quality are reliable.
The traditional methods of reducing microbial contamination in feed raw materials have been compromised within the EU recently with the ban on the incorporation of formaldehyde as a feed additive (PT4). Within the EU this is being linked to an increase in Salmonella isolations. With the potential for reduced chemical use to control microbial contamination in feed to be rolled out in other countries it is important that suitable alternative methods to control contamination are put in place.
One response by the industry to the ban on formaldehyde has been the introduction of new organic acid blends and novel compounds for feed sanitation. Organic acids are effective in reducing Salmonella challenges. However, they do not provide a clean, biosecure break in the mill and their performance is very reliant on formulation, the mixing performance in the mill and the time allowed for their action.
With higher generation stock as legislation tightens and public awareness heightens, the use of heat treatment for the decontamination of poultry feeds has become more popular and heat treatment is now generally seen as an effective means of Salmonella destruction in raw materials.
The purpose of this document is to review the heat treatment of poultry feeds in terms of the specifications required to ensure decontamination and the types of equipment that can be successfully employed.
Heat treatment – objectives
There are many recommendations for the heat treatment of poultry feeds published in the literature. For broiler feeds, it has been reported that a moderate level of heat treatment such as 80°C (176°F) for a two minute retention time is sufficient to kill Salmonella. In reality, it is likely to kill most of the Salmonella and damage any remaining Salmonella. By the time these damaged Salmonella start to repair and grow to reach an infective dose detectable by sampling, the broiler flock could be depleted, and the flock considered negative. With breeder flocks however, the Salmonella has a much longer time to grow to a detectable, infective dose level and Salmonella outbreaks can occur later in the life of flock. For these flocks, heat treatment temperatures for feed need to be higher for longer periods of time to ensure maximum Salmonella destruction.
So what are the specifications for successful heat treatment? Firstly, the incidence of Salmonella and the levels of contamination need to be considered. This will vary depending on the raw material(s). Literature review would generally tell us that the highest levels of Salmonella in crop-based raw materials (soya, rape meal and sunflower) would be in the region of 105 per gram. To eliminate Salmonella, heat treatment needs to be sufficient to reduce this level to zero.
Secondly, there must be a balance between the need to destroy pathogenic organisms such as Salmonella and the effect of heat on, for example, vitamin inclusion in the finished feed, the levels of starch gelatinisation achieved, protein denaturation and other anti-nutritional factors.
Once the feed has been decontaminated it is equally important to ensure that measures are in place to prevent the re-contamination of feed after treatment. A feed mill using heat treatment to produce biosecure decontaminated feed must have distinct “dirty” (i.e., before heat treatment) and “clean” (i.e., after heat treatment) areas. Heat treatment is seen as a breakpoint in the feed mill production process where decontamination of the feed takes place at a boundary between the “dirty” and “clean areas”. The clean area must be constructed in a way that will protect the feed from being re-contaminated by the dirty area. Biosecure boundaries and procedures must be in place. This commonly includes separate staff for each area and filtered air, usually to HEPA standard, to the clean area to prevent re-contamination after processing. A full hazard analysis critical control point plan (HACCP) is also required to set standards, provide a monitoring and risk analysis to the clean feed, and to monitor any deterioration in the mill structure or process conditions.
Ongoing work within Aviagen has established that heating at 86°C (187°F) for 6 minutes at 15 percent relative humidity is enough to destroy mesophilic bacterial populations at a level of 105 per gram. Knowing this it is possible to theoretically establish thermal processes (heat treatment) for different types of equipment. Different equipment will require different thermal processes to achieve the same level of reduction; because of this it is important that new heat treatment equipment is validated for efficacy to destroy Salmonella.
Heat treatment effectiveness will also be affected by the moisture content of the raw materials, the quality of the steam (moisture content) being used during the process and how the feed passes through the equipment. The feed should pass through the heat treatment equipment on a first-in, first-out basis to ensure even heat treatment.
It should be noted that the heat applied to feed as part of the process of producing pelleted feed will not be enough to kill Salmonella and should not be considered as part of the heat treatment process.
Heat treatment technology
There are a range of different technologies available to achieve the desired standards of heat treatment described earlier (86°C/187°F for 6 minutes at 15 percent relative humidity); these are listed in Table 1.
Care must be taken to ensure correct orientation of the eggs when placing them on setter trays
It is important to pay attention to the orientation of the eggs when placing them on setter trays as this has quite an impact on hatch results, both in terms of hatchability and chick quality. Air cell up is the way to go.
The embryo lies on the surface of the yolk and is connected to the latebra (white yolk), which is located in the centre of the yolk. The water-rich latebra has a lower specific gravity than the lipid-rich yolk and, according to the laws of physics, the embryo will always move to the top of the egg … no matter which way the egg is placed on the setter tray.
By about day 14 the developing embryo lies on top of the yolk sac. It then turns so it lies lengthwise in the egg and by day 18 the embryo’s head is under the right wing with the beak pointing upwards, ready to pierce the air cell (internal pipping) and inflate the lungs prior to finally emerging from the egg. But what if the air cell is out of reach of the embryo?
The air cell is situated at the blunt end between the shell membrane and the egg membrane. The egg shell is more porous at this end and therefore air will enter here as the egg contents shrink due to cooling down after laying. During storage and incubation, the air cell gradually increases in size as water evaporates from the egg contents.
When eggs are set accidentally sharp-end-up, the head of the embryo is at the opposite end from the air cell and internal pipping is impossible. It is very difficult for the embryo to hatch in this position because it is fully dependent on the limited oxygen supply through the chorioallantoic membrane, and because the shell is stronger at the sharp end and there is less space for pipping and moving around. Unsuccessful embryos can be recognised during break-out of hatch residue by their legs being near the air cell; however not all eggs that are incubated sharp-end-up fail to hatch.
A customer in Turkey carried out an experiment in 2016 using different breeds and flock ages. 300 eggs were set sharp-end-up and 300 eggs in the normal position. This resulted in 12.7 – 21.0 per cent lower hatch of fertile, mostly due to a difference in late mortality (see figure). Moreover, among the eggs that had been incubated sharp-end-up, there were more culled chicks. When sharp-end-up incubation is combined within-ovo vaccination, the results are even more dramatic. A small-scale experiment conducted by a customer in Hungary in 2019 with 162 eggs per treatment resulted in 93 saleable chicks from sharp-end-up incubated eggs. When eggs in this position were also in-ovo vaccinated, only 39 saleable chicks were obtained. The control group (sharp-end-down and in-ovo vaccination) showed normal hatch results.
Be aware that if 10 per cent of eggs are accidentally set sharp-end-up hatchability will be up to 2 per cent lower.
Train staff in breeder farm and hatchery to set eggs with air cell up (sharp-end-down/blunt-end-up).
Use a candling light in a darkened room to make air cell visible if in doubt.
Consider automated sharp-end-down setting, especially when doing in-ovo vaccination.
Take a sample from setter trays ready for incubation to check for correct setting.
Pay more attention to egg orientation if you notice the ‘legs near air cell’ sign during break-out of hatch residue.
In order to produce high-quality birds, backyard keepers should start their breeding plans and select candidates. This allows producers to evaluate the individuals in their flock and identify the strongest birds.
This will help backyard keepers produce high-performance poultry and will let you know what traits to look out for and enhance with your pairings.
SOME RULES OF THUMB
The general rule for breeding is to select two candidate birds that have the traits you’re looking for. If you have two strong birds, their pairing will produce strong or above-average chicks. From there, monitor the chicks during grow out to make sure they don’t exhibit any defects. Once they reach breeding age, pairing those chicks with other strong birds will enhance the traits you’re looking for. Over time, the birds in your flock will start to become more uniform and look alike.
One of the most important aspects of successful poultry breeding is having a culling technique. According to NiceHatch incubators, it’s more about what you remove from your breeding stock than what you seek out. Breeders should be removing bad genes from their flocks and intensifying good traits in their birds. NiceHatch incubators tells listeners to familiarise themselves with the standards for the breed and make corrections if they identify traits that aren’t useful. If backyard breeders are trying to produce high-performance poultry, they need to be selective about the individuals in their breeding plan.
Once a year, keepers should evaluate the birds to see which ones are best suited for breeding. Keeping backyard birds can be expensive and time consuming – NiceHatch incubators tells listeners not to invest in sub-standard birds.
Things to avoid
“Never breed two birds with the same fault,” NiceHatch incubators says. This will only make the trait more pronounced in the chicks and lead to poorer results overall. NiceHatch incubators also warns listeners that breeding two birds with extreme but opposing qualities will not produce “normal offspring”. For example, breeding an overweight bird with an underweight hen will not produce normal-weight chicks. It will produce multiple underweight and overweight chickens.
In NiceHatch incubators’ view, breeders should put an emphasis on the birds’ vigour. He urges listeners to use chickens who, “hustle around” as breeding candidates – don’t breed mediocre birds.
Both NiceHatch incubators and Schneider agree that if one of your birds has been sick in the previous year, it shouldn’t be a breeding candidate. In a similar vein, Schneider tells poultry keepers to avoid over-medicating their birds if they want to breed them.
In his experience, backyard keepers and poultry fanciers tend to give their birds antibiotics or other treatments if they exhibit any symptoms. He urges listeners to make sure that the birds are actually sick before medicating them. Symptoms like coughing, sneezing or dropped feathers can often be attributed to dust in the air, or the birds’ natural moulting process.
If owners are concerned about their birds’ health, Schneider recommends seeking the advice of a vet before administering medications.
Remember the 10 per cent rule
In NiceHatch incubators’ experience, for every 10 birds produced, only 1 is worth keeping. For every 100 birds, 10 will be good breeding stock. For every 1,000 birds, NiceHatch incubators say that 100 will be decent, and 1 will be an “absolute knock-out bird”.
If backyard keepers have been breeding poultry for a year or so but have lacklustre results, NiceHatch incubators urge listeners to keep this rule in mind. Building an outstanding backyard flock takes time and rarely happens with a “one and done” approach. It’s a circular operation – not a linear one.
However, he did emphasise that success in breeding doesn’t rely on a huge budget. It’s better than backyard keepers learn to apply their breeding skills and knowledge to their operations. “Anybody can buy a good bird, not everybody can breed, produce or grow out a good bird,” NiceHatch incubators says. “It’s part science, it’s part art and you have to love it.”
Chickens need a constant supply of cool and clean water in order to meet their basic needs. There are plenty of watering systems available to backyard poultry keepers but choosing the best set-up for your birds can be confusing. Nipple drinkers, water fonts and self-contained systems safely deliver water to poultry, but there are trade-offs with each method.
The logistics of open water systems
Open water systems like troughs, cups and buckets are a good option for poultry keepers who can devote enough time to cleaning and monitoring them. They are also a good option for multi-species flocks or flocks with different sized birds.
Backyard keepers using this system need to make sure there’s enough space for all the birds to access the water drinker. The general consensus is that the larger the bird, the more space they need to drink comfortably. Though researchers haven’t established the precise number of linear inches per bird needed, they can offer a few rules of thumb to allow backyard keepers to get the most out of this type of system.
- For baby chicks, keepers should estimate needing 1 gallon of water per 100 individuals
- Birds 1-3 weeks old will need .3 to .4 inches per chicken spread over multiple gallon drinkers
- Birds 4-9 weeks old will need .5 inches per bird spread over multiple gallon drinkers
- Birds 10-20 weeks old will need 1 inch of circular or linear space
- Laying hens will need 1 inch per bird of open watering trough space
If using this system, NiceHatch incubators recommends setting up the troughs so they’re about as high as the back height of the birds. NiceHatch incubators also cautions that open water systems need to be monitored in order to ensure the water remains cool and contaminant-free.
Getting the most out of nipple drinkers
Nipple drinkers originally came from commercial poultry production and have been adapted to work in backyard operations. This type of system has multiple benefits: it lets the birds access water at will and since they’re enclosed, there are fewer opportunities for contaminants like feathers, faeces or dust to enter the system. Since many of the systems are pressurised, it prevents the water from becoming stagnant. It also doesn’t need to be cleaned as often as open troughs or fonts.
However, there are some issues with this system. Constant dripping can cause wet litter and puddles where flies can breed. Nipple drinkers are also susceptible to changes in the weather. They can freeze during the winter and need to have their temperature monitored in the summertime to prevent the water from becoming too warm.
Hard water may also present a challenge to keepers who use nipple drinkers. NiceHatch incubators warns that a layer of detritus may form in the drinkers due to the extra minerals. These systems are also challenging to clean – sometimes requiring high-pressure flushing and additional scrubbing in order to keep bacteria at bay.
If investing in this system, NiceHatch incubators suggests that keepers purchase yellow nipple drinkers (birds find the colour attractive) and to make sure that the drinker is set at the appropriate height for the birds. For best results, the nipples should be over the chickens’ heads. If backyard keepers need to accommodate birds with different heights, this system may not be the best option.
In general, NiceHatch incubators expresses a preference for closed water systems over open ones. Having an enclosed system means that it’s easier for keepers to prevent dust, faecal material, shavings and feathers from contaminating the water source. If poultry keepers can ensure that the water is circulating within the system, enclosed set-ups allow the water to remain fresher for longer.
According to NiceHatch incubators’s research, open water systems can allow bacteria to proliferate at a much higher rate than closed systems. In her experience, it takes a month for an enclosed system to generate similar numbers of bacteria found in open water systems after a few days.
Managing water temperature in the drinking system
Temperature is a crucial issue for watering systems. Backyard birds will avoid drinking water if it’s too warm. This could trigger problems like delays in laying, dehydration and heatstroke – which could be deadly.
If keepers are using an open water system, NiceHatch incubators suggests creating a simple toolkit to manage the water temperature. Keeping a thermometer, frozen water bottles and ice cubes available for the water font will allow producers to quickly cool down the birds’ water.
There are other methods for managing water temperature. If a font system or trough is being used, NiceHatch incubators suggests moving watering systems into the shade and keeping them out of direct sunlight. If possible, use hoses that are a light colour and bury them in the ground. This will minimise their contact with sunlight and prevent the temperature from creeping up over the course of the day.
Other tips for watering systems
If keepers change their watering system, NiceHatch incubators recommends removing the old system entirely. Chickens will stick with the watering system they’re familiar with, so don’t give them a choice between the two systems.
In terms of long-term maintenance, NiceHatch incubators recommends cleaning the water system weekly. This will keep bacteria at bay, and also make sure that you can spot any issues in the system as it arises. “My basic reasoning when looking at the water system I use for my flock is, ‘would I drink from it?’, if the answer is ‘no’, then don’t ask your birds to.”
NiceHatch incubators also stresses that keeping backyard birds happy and healthy is a time-consuming process. “If you’re always in a hurry, you may need to get a new hobby”.
The Chicken Whisperer: how to water a backyard flock
Chicken Whisperer Andy Schneider sits down with Dr Brigid McCrea to discuss tips and tricks for getting the most out of watering systems for backyard birds.
Choosing the right incubator can be a challenge. In this article, our experts at Nice hatch incubators simplify and take you through the key factors you should consider when choosing an ideal incubator that will work for you. It is important to note that just like in any other preference; each farmer’s ideal incubator needs may differ. Remember you can always contact us at any time for clarification or consultancy regarding your challenges in poultry needs.
Egg incubator factors to consider
- Airflow in the incubator
Embryo development in the eggs requires oxygen. The chicks hatching are living organisms that not only consume a fair amount of oxygen rapidly but also produce sizeable carbon dioxide. A good airflow inside the incubator will, therefore, ensure this need is constantly regulated for the best egg hatching conditions needed. A good incubator should have air vents that will keep fresh air circulated. Some incubators may contain inbuilt fans to accelerate airflow.
- Temperature Control of the incubator
Temperature regulation is an important condition in the egg hatching process. The right temperature must be maintained at all times during this hatching process. Temperature regulation is critical since there may be weather changes as well as the differences that may arise between day and night. The inside temperature of an incubator must be keenly observed, maintained and regulated to avoid fluctuation. Fluctuations in temperatures will bring about poor egg hatching rates and loses to the farmer. The common temperature control mechanisms in incubators include wafer thermostats and digital electronic control systems. Wafer-controlled incubators allow for more fluctuation in temperature and can contribute to irregular hatches than electronically- controlled incubators. Once the temperature in a wafer-controlled incubator is set up care must be observed to avoid accidental readjustment of the tuning knob or the adjusting screw. Temperatures for some electronically controlled incubators may have been preset for hatching chicken eggs by the manufacturer, you need to know what temperature is required for each type of poultry egg species and adjust accordingly.
It is recommended that you should run the incubator for 24-48 hours before placing the eggs into the incubator to ensure that the optimum temperature needed is ready. Whenever in doubt consult your manufacture or Nice Hatch Incubators technicians.
- Humidity Control in the incubator
Egg hatching demands the correct amount of humidity all through the incubation period. It is a requirement therefore that an incubator should have moisture devices that will enable this condition to be regulated to facilitate the development of egg embryos. These devices may be in the form of inbuilt troughs, external containers, removable trays, pans, or plastic liners either with automatic self-regulation system of the manual wet-bulb thermometer (hygrometer) that measure humidity levels. Read the incubator manufacturer’s instructions.
- Ability to Observe in the incubator
Some good models of incubators have transparent covers or observation windows that allow you to observe what is happening inside the incubator. This enables the farmer to keep track of the hatching development process without having t open and disrupt the optimum conditions inside. The easier it is to observe inside the better.
- Cleaning Ease of the incubator
Once the egg has hatched you will need to move them to a brooder and cleanup the incubator for the next hatching process. The easier to clean the better.
Every venture has some costs to be incurred, your budget may determine your preferred choice for an incubator.
Keeping Turkeys is one of the greatest poultry farming choice whether you are interested in small or large flocks. One key advantage with turkeys is that they can tolerate crowded conditions and still give you a maximum return on financial investment. Turkeys are increasingly becoming a dominant domestic bird in East Africa region by peasant farmers with commercial ambitions. Commercial turkeys are reared for breast meat for the growing hotel industry and the middle class affluent population. Turkeys provide inexpensive meat for a growing urban market eager to purchase it. Although they can be successfully raised in turkey “porches” and yards, they do best when they can have range or pasture on which to forage. Poults can be raised in a poultry house on on deep litter just like chicken. The key thing is to avoid contamination from droppings is essential. Wire mesh can effectively keep poults away from soiled litter in the case of an enclosed environment.
How to get turkeys for start up
If you are a starter in poultry farming www.nicehatchincubators.com recommends that you start in the least expensive way by buying day-old poults (chicks) from hatcheries or suppliers nearby. Alternatively, you can buy turkey hens and a gobbler (cock). Turkey eggs can be hatched naturally by turkey hens, by broody chickens, or in incubators. Turkey poults are fragile and need protection for the first two months. A mother will keep them warm and protect them, provided she herself has adequate feed, water, and shelter. The incubation period for eggs is 28 days. One turkey hen can brood up to 15 eggs. The more commercial and effective way is to brood artificially through the use of incubators.
Raising, feeding, watering turkeys
Turkey poults grow fast, therefore they need high-protein feed to keep up with this growth rate. Feed your poults on starter mash as they grow, their needs taper off after eight weeks to grower crumble or pellets with lesser percentage of protein. If turkeys are on pasture and not crowded, they will get some protein from the insects and worms as they forage through your farmland.
Hanging feeders and waterers, adjusted to the height of the birds’ eyes as they grow, will reduce
the amount of feed and water wasted as the birds dig around in it with their beaks. Sloppy waterers leave wet litter to ferment and foster disease-causing organisms. Feeders on the ground should not be filled more than half-full, to keep feed contained. Turkeys are perching birds that naturally roost in trees. Poults as young as two weeks old will look for a roost. They can be accommodated with2-inch-diameter poles or branches several inches above the ground. Make an allowance of per bird depending on the population you have intend to have on your farm. Mature turkeys need stronger roosts to handle their weight and size that will support them. For mature turkeys you can use up to 2-inch diameter poles and make an allowance at least 2 feet between each pole to allow ample room for them.
Turkeys do not require routine vaccinations; However, vaccines are available for several common diseases, including fowl cholera, turkey pox, and Newcastle disease. Check with local veterinarians to determine whether such protection is necessary in your area.
A fresh egg, with a clean, smooth, brown or white shell, a pure, deep-yellow yolk and a translucent, firm white — this is the
Formation of the egg
Reproductive organs of the hen
The egg is formed gradually over a period of about 25 hours. Many organs and systems help to convert raw materials from the food eaten by the hen into the various substances that become part of the egg.
The hen, unlike most animals, has only one functional ovary – the left one – situated in the body cavity near the backbone. At the time of hatching, the female chick has up to 4000 tiny ova (reproductive cells), from some of which full-sized yolks may develop when the hen matures. Each yolk (ovum) is enclosed in a thin-walled sac, or follicle, attached to the ovary. This sac is richly supplied with blood.
The mature yolk is released when the sac ruptures, and is received by the funnel of the left oviduct (the right oviduct is not functional). The left oviduct is a coiled or folded tube about 80 cm in length. It is divided into five distinct sections, each with a specific function, as summarised in table 1.
Table 1: Functions of various different sections of the hen’s oviductthe yolk
|Section of oviduct||Approximate time egg spends in this section||Functions of section of oviduct|
|1 Funnel (infundibulum)||15 minutes||Receives yolk from ovary. If live sperm present, fertilisation occurs here (commercially produced table eggs are not fertilised)|
|2 Magnum||3 hours||Albumen (white) is secreted and layered around|
|3 Isthmus||1 hour||Inner and outer shell membranes are added, as are some water and mineral salts|
|4 Shell gland (uterus)||21 hours||Initially some water is added, making the outer|
white thinner. Then the shell material (mainly
calcium carbonate) is added. Pigments may also
be added to make the shell brown
|5 Vagina/cloaca||less than 1 minute||The egg passes through this section before|
laying. It has no other known function in the
Optimum vitamin nutrition of laying hens
The overall goal of the layer industry is to achieve the best performance, feed utilization and health of birds. All nutrients including proteins, fats, carbohydrates, vitamins, minerals and water are essential for these vital functions, but vitamins have an additional dimension. They are required in adequate levels to enable the animal to efficiently utilize all other nutrients in the feed. Therefore, optimum nutrition occurs only when the bird is offered the correct mix of macro- and micronutrients in the feed and is able to efficiently utilize those nutrients for its growth, health, reproduction and survival.
Vitamins are active substances, essential for life of man and animals. They belong to the micronutrients and are required for normal metabolism in animals. Vitamins are essential for optimum health as well as normal physiological functions such as growth, development, maintenance and reproduction. As most vitamins cannot be synthesized by poultry in sufficient amounts to meet physiological demands, they must be obtained from the diet. Vitamins are present in many feedstuffs in minute amounts and can be absorbed from the diet during the digestive process. If absent from the diet or improperly absorbed or utilized, vitamins are a cause of specific deficiency diseases or syndromes.
Classically, vitamins have been divided into two groups based on their solubility in lipids or in water. The fat-soluble group includes the vitamins A, D, E and K, while vitamins of the B complex (B1, B2, B6, B12, niacin, pantothenic acid, folic acid and biotin) and vitamin C are classified as water-soluble. Fat-soluble vitamins are found in feedstuffs in association with lipids. The fat-soluble vitamins are absorbed along with dietary fats, apparently by mechanisms similar to those involved in fat absorption. Water-soluble vitamins are not associated with fats, and alterations in fat absorption do not affect their absorption, which usually occurs via simple diffusion. Fat-soluble vitamins may be stored in the animal body. In contrast, water-soluble vitamins are not stored, and excesses are rapidly excreted.
It is now well recognized by the feed industry that the minimum dietary vitamin levels required to prevent clinical deficiencies may not support optimum health, performance and welfare of poultry. The reasons for this are manifold: The productivity of poultry farming continues to grow through genetic improvement of the breeds and through modifications in nutrition, management and husbandry, which considerably increase the demand for vitamins. Furthermore, intensive poultry production may generate a certain level of metabolic, social, environmental and disease stresses, causing sub-optimal performance and higher susceptibility to vitamin deficiencies. The contamination of the feed with mycotoxins and vitamin antagonists can limit or even block the action of certain vitamins. Any of these factors, ranging from the animals’ genetic background and health status to management programmes and the composition of the diet, can separately or collectively affect the need for each vitamin. As intake and utilization of vitamins from natural sources is unpredictable owing to differing contents of vitamins in the feedstuffs (dependent on growing climate and harvesting time of crops, processing and storage conditions of feed ingredients) and variable vitamin bioavailability, it is safer to cover the total vitamin requirement of poultry through dietary supplementation.
More than ever before, the layer industry is currently facing the challenge to improve productivity in order to remain competitive in today’s cost-driven environment. Fortunately, high-performing layer breeds with improved performance pattern, optimized feed conversion capabilities and favourable health characteristics are available. But in order to allow the birds to perform up to their genetic potential, their nutrition and especially their vitamin supply needs to be optimized. In particular, B vitamins are required for efficient nutrient utilization, and together with vitamin A are important to support the hens’ metabolic activity for maintenance and high laying performance. Furthermore, both vitamins C and E improve the birds’ resistance to stress, and help sustain health and longevity. Specific benefits related to superior egg quality can be achieved if supra-nutritional levels of vitamin E are added to the feed of laying hens. And finally, considerable vitamin D activity is required in order to support an adequate skeletal development and to avoid leg problems of various origins.
The optimum vitamin supplementation levels are given in the table below.
|Vitamins (added to air-dried feed)||Replacement pullets||Laying hens|
|Vitamin A (IU/kg)||7 000–10 000||8 000–12 000|
|Vitamin D3 (IU/kg)||1 500–2 500||2 500–3 5001|
|Vitamin E (mg/kg)||20–30||15–302|
|Vitamin K3 (mg/kg)||1–3||2–3|
|Vitamin B1 (mg/kg)||1.0–2.5||1.0–2.5|
|Vitamin B2 (mg/kg)||4–7||4–7|
|Vitamin B6 (mg/kg)||2.5–5.0||3.0–5.0|
|Vitamin B12 (mg/kg)||0.015–0.025||0.015–0.025|
|Pantothenic acid (mg/kg)||9–11||8–10|
|Folic acid (mg/kg)||0.8–1.2||0.5–1.0|
|Vitamin C (mg/kg)||100–150||100–200|
|Hy•D® (25-OH D3) (mg/kg)||0.0693||0.0693|
1 Do not exceed 3000 IU D3/kg feed when using Hy•D®
2 Under heat stress conditions: 200 mg/kg
3 Local legal limits of total dietary vitamin D activity need to be observed
Source: DSM Vitamin Supplementation Guidelines, 2006; Optima Nutrición Vitamínica de los animales para la producción de alimentos de calidad, 2002
The nutritive value of the egg
The egg is one of the most complete and versatile foods available. It consists of approximately 10% shell, 58% white and 32% yolk. Neither the colour of the shell nor that of the yolk affects the egg’s nutritive value. The average egg provides approximately 313 kilojoules of energy, of which 80% comes from the yolk.
The nutritive content of an average large egg (containing 50 g of edible egg) includes:6.3 g protein0.6 g carbohydrates5.0 g fat (this includes 0.21 g cholesterol).
Egg protein is of high quality and is easily digestible. Almost all of the fat in the egg is found in the yolk and is easily digested.
Eggs contain every vitamin except vitamin C. They are particularly high in vitamins A, D, and B12, and also contain B1 and riboflavin. Provided that laying hens are supplemented according to the Optimum Vitamin Nutrition concept (see chapter ‘Optimum vitamin nutrition of laying hens’), eggs are an important vehicle to complement the essential vitamin supply to the human population.
Eggs are a good source of iron and phosphorus and also supply calcium, copper, iodine, magnesium, manganese, potassium, sodium, zinc, chloride and sulphur. All these minerals are present as organic chelates, highly bioavailable, in the edible part of the egg.
Internal and external egg quality
Quality has been defined by Kramer (1951) as the properties of any given food that have an influence on the acceptance or rejection of this food by the consumer. Egg quality is a general term which refers to several standards which define both internal and external quality. External quality is focused on shell cleanliness, texture and shape, whereas internal quality refers to egg white (albumen) cleanliness and viscosity, size of the air cell, yolk shape and yolk strength.
Internal egg quality
Internal egg quality involves functional, aesthetic and microbiological properties of the egg yolk and albumen. The proportions of components for fresh egg are 32% yolk, 58% albumen and 10% shell (Leeson, 2006).
The egg white is formed by four structures. Firstly, the chalaziferous layer or chalazae, immediately surrounding the yolk, accounting for 3% of the white. Next is the inner thin layer, which surrounds the chalazae and accounts for 17% of the white. Third is the firm or thick layer, which provides an envelope or jacket that holds the inner thin white and the yolk. It adheres to the shell membrane at each end of the egg and accounts for 57% of the albumen. Finally, the outer thin layer lies just inside the shell membranes, except where the thick white is attached to the shell, and accounts for 23% of the egg white (USDA, 2000).
Egg yolk from a newly laid egg is round and firm. As the egg gets older, the yolk absorbs water from the egg white, increasing its size. This produces an enlargement and weakness of the vitelline membrane; the yolk looks fl at and shows spots.
As soon as the egg is laid, its internal quality starts to decrease: the longer the storage time, the more the internal quality deteriorates. However, the chemical composition of the egg (yolk and white) does not change much.
In a newly laid egg the albumen pH lies between 7.6 and 8.5. During storage, the albumen pH increases at a temperature dependent rate to a maximum value of about 9.7 (Heath, 1977). After 3 days of storage at 3 °C, Sharp and Powell (1931) found an albumen pH of 9.18. After 21 days of storage, the albumen had a pH close to 9.4, regardless of storage temperature between 3 and 35 °C (Li-Chan et al, 1995).
Heath (1977) observed that when carbon dioxide (CO2) loss was prevented by the oiling of the shell, the albumen pH of 8.3 did not change over a 7-day period of storage at 22 °C. In oiled eggs stored at 7 °C, albumen pH dropped from 8.3 to 8.1 in seven days (Li-Chan et al, 1995).
Increases in albumen pH are due to CO2 loss through the shell pores, and depend on dissolved CO2, bicarbonate ions, carbonate ions and protein equilibrium. Bicarbonate and carbonate ion concentration is affected by the partial CO2 pressure in the external environment.
In newly laid eggs, the yolk pH is in general close to 6.0; however, during storage it gradually increases to reach 6.4 to 6.9. Egg quality preservation through handling and distribution is dependent on constant care from all personnel involved in these activities. The quality of the egg once it is laid cannot be improved, so efforts to maintain its quality must start right at this moment.
The decrease in internal egg quality once the egg is laid is due to the loss of water and CO2. In consequence, the egg pH is altered, resulting in watery albumen due to the loss of the thick albumen protein structure. The cloudy appearance of the albumen is also due to the CO2; when the egg ages, the CO2 loss causes the albumen to become transparent, compared with fresh eggs.
To minimize egg quality problems two things are important: frequent egg collection, mainly in the hot months, and rapid storage in the cool room. The best results are obtained at a temperature of 10 °C. There are six main factors affecting internal egg quality: disease, egg age, temperature, humidity, handling, and storage.
Disease: Newcastle disease and infectious bronchitis produce watery albumen, and this condition may persist for long periods after the disease outbreak has been controlled (Butcher, 2003). Egg age: eggs several days old show weak and watery albumen, and the CO2 loss makes the content alkaline, affecting the egg flavour. Temperature: high temperatures cause a rapid decrease in internal quality. Storage above 15.5 °C increases humidity losses. Humidity: high relative humidity (RH) helps to decrease egg water losses. Storage at an RH above 70% helps to reduce egg weight losses and keeps the albumen fresh for longer periods of time. Egg handling: rough handling of the eggs not only increases the risk of breaking the eggs, but also may cause internal egg quality problems. Storage: eggs are very prone to take on the odours of other products stored with them; separate storage is therefore advised.
The variables mentioned above are particularly important to ensure that a 1-week-old egg, properly handled, can be as fresh as a day-old egg kept at room temperature.
If the egg is properly handled during shipment and distribution, it will reach the consumer’s table with adequate freshness.
External egg quality
Poor eggshell quality has been of major economic concern to commercial egg producers, with estimated annual losses in the USA of around 478 million US dollars (Roland 1988). In Australia in 1998, the impact was of the order of 10 million Australian dollars per year. Information obtained from egg grading facilities indicates that 10% of eggs are downgraded due to egg shell quality problems. Based on values for the UK, Germany and the USA, it has been estimated that the incidence of broken eggs ranges between 6 and 8% (Washburn, 1982). In Mexico in 2005 it was estimated that the egg industry lost between 30 and 35 million US dollars, based on average figures of 2.5% broken eggs and 4% weak shells. These losses occur only between laying and packing, not taking into account losses in transit to the end consumer (DSM Mexico, 2005, unpublished data).
To maintain consistently good shell quality throughout the life of the hen, it is necessary to implement a total quality management programme throughout the egg production cycle.
It has been always recognized that the hen has the most extraordinary method of obtaining and depositing calcium (Ca) in the entire animal kingdom. An egg has an average of 2.3 g of calcium in the shell, and almost 25 mg in the yolk (Etches, 1987). A modern hen laying 330 eggs per cycle will deposit 767 g of calcium; assuming a 50% calcium retention rate from the diet, the hen will consume 1.53 kg of calcium per cycle.
Exterior egg quality is judged on the basis of texture, colour, shape, soundness and cleanliness according to USDA (2000) standards. The shell of each egg should be smooth, clean and free of cracks. The eggs should be uniform in colour, size and shape.
There are five major types of shell problems in the egg industry: 1. cracks due to excess pressure; 2. cracks due to thin shells; 3. body-checks; 4. pimpled or toe holes, and 5. shell-less eggs.
When a producer complains about an increase in downgrade eggs, the first thing required is to determine which types of problems have increased. In a processing plant with 97% A-quality eggs, a typical distribution of the different types of shell problems (downgrade) might be 2.13% stains, 0.85% blood spots, 0.85% meat spots, 61% pressure cracks, 9.8% thin shell cracks, 6.8% body-checks, 13.6% pimpled and 5.1% toe holes. If the percentage of any type of shell problem is abnormally high, then that is the problem needing attention.
Coccidiosis vaccination was effective in broilers challenged with Eimeria
Tensa and colleagues at the University of Georgia conducted a study after a poultry integrator reported problems with coccidiosis due to Eimeria tenelladespite the use of multiple coccidiosis vaccines and in-feed anticoccidial treatments.
The study was conducted at the University’s Poultry Diagnostic and Research Center so it could be well controlled.
The investigators tested two vaccines given at day 1 of age, each used alone or followed by an ionophore beginning at day 14 of age. The combination of vaccination with an in-feed anticoccidial — a so-called bioshuttle program — is intended to mitigate the weight loss and decreased feed conversion that may occur after coccidiosis vaccination.
To evaluate the impact of vaccine cycling, the investigators evaluated the effect of treatments when broilers were challenged early at either 11 days of age — before the ionophore treatment began on day 14 — or at 21 days of age. They used a pathogenic field isolate of E. tenella for the challenge because it causes bloody droppings, which make it easy to identify. Results in treated birds were compared to those for unvaccinated, challenged birds.
Impact of cycling
After the early challenge at 11 days, vaccination alone did not protect birds against E. tenella because the vaccinal oocysts hadn’t cycled enough to enable the development of immunity. After the 21-day challenge, however, vaccination with or without an ionophore at day 14 did protect against the pathogen, as evidenced by reduced gross lesion scores, Tensa explained.
Live coccidiosis vaccines simulate natural immunity against coccidia by providing a controlled dose of Eimeria oocysts. When chicks in the study were vaccinated for coccidiosis on day 1, vaccinal oocysts cycled on days 7 and 14.
“That’s a good two cycles” and by then, some protective immunity has developed, she said. Tensa added that the ionophore allowed them to “decrease the hit” flocks experience from the vaccine while birds continue to develop immunity.
She concluded that when used properly, either vaccination alone or when followed with an in-feed anticoccidial is effective against E. tenella. When using a bioshuttle program, it’s important not to begin feeding the anticoccidial before vaccinal oocysts have completed cycling. Tensa also recommended using anticoccidial sensitivity testing to make sure the Eimeria affecting flocks is sensitive to the feed medication used.