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HATCHERY SIGNALS A P R A C T I C A L G U I D E T O I M P R O V I N G H AT C H I N G R E S U LT S
Contents Variation in the hatch moment 139 Pull time 140 141 Unhatched eggs/dead in shell Count and assess unhatched eggs 142 143 Hatching systems and early feeding On-farm hatching 145 10. Chick quality 148 149 Signals from empty eggshells Pipping height and pipping line 151 152 Infection pressure Meconium 153 154 Chick temperature Chick yield 155 156 Drying off or dehydrating? Residual yolk 157 158 Absorption of residual yolk 159 Chick weight and length The signals given by chick length 160 161 Working at the take-off table Selection criteria 162 Navel and cloaca 163 Belly 164 Feathering 165 Legs 166 Beak 167 Serious abnormalities 168 169 Scoring systems Abnormalities and their causes 171 172 Downgraded chicks Sex determination 173 174 Sexing and sex-linked genetic traits Vaccination at the hatchery 176 11. Chick transport and delivery 178 179 Chick storage Preparation for chick transport 180 181 Cargo area climate Ventilation during transport 182 183 International transport Transport to and from airports 184 185 Feed and water during long transport Chick delivery 186 Hygiene during delivery 187 On the poultry farm 188 House conditions inspection 189 First week mortality 190 Index 191
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6. Egg transport and storage 76 77 Condensation point = dew point Transition moments 78 78 Dry bulb and wet bulb thermometer Climate during transport 80 81 Jolts and vibrations Egg transport and logistics 82 83 Inspection of incoming eggs Storage at the hatchery 84 85 Climate conditions during storage Storage duration 86 87 Longer storage Turning during storage 88 SPIDES 89 Disinfecting eggs 90 91 Dry (fumigation) and wet disinfection After disinfection 92 Disinfectants for eggs 93 7. Setting 94 95 Do not mix Origin 96 97 Parent stock age Laying date 97 98 Preparing the incubator Setting eggs 99 100 Pre-warming (single-stage) Pre-warming (multi-stage) 100 Climate conditions during setting 101 Transition from warming to cooling 102 103 Humidification during setting First few days: ventilation inlets closed 104 105 Day 4 to 11: regulate based on RH Heat distribution in the incubator 106 107 Egg turning during setting The importance of turning 108 109 Monitor turning Monitoring setter conditions 110 111 Constantly improved measurement Candling 112 8. Transfer 114 115 Which egg has a live embryo? Infertile eggs, bangers, late mortalities, and living embryos 116 What do key indicators tell you? 118 In-ovo vaccination 120 The optimal timing 121 Suitability of the egg 122 Hygiene is extremely important 122 In-ovo sexing 123 Transfer 126 Hygiene at transfer 128 Breakout analysis on day 18 129 Eggs in a clean hatcher 130 Hatcher baskets 131 9. Hatching 132 Air temperature in the hatcher 133 Humidity in the hatcher 134 Position in the egg 135 Internal pipping 136 External pipping 137 The hatch window 138
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1. Introduction 4 Key link 5 6 How the chain works Incubation is interaction 7 8 Each incubator is different Hatchery management 9 10 The role of the hatchery manager Information exchange 11 13 The signals concept Critical batches, locations and moments 15 2. The incubation process 18 19 The anatomy of the hatching egg Development of an embryo 20 From natural brooding to artificial incubation 22 The environment of the egg 24 Heat and temperature 25 26 Gas exchange of the embryo The importance of uniformity 27 3. Principles of artificial incubation 28 28 Broilers and laying hens Eggshell temperature is key 30 31 Incubation temperature Temperature settings 32 33 Heat production by the embryo Ventilation 34 Carbon dioxide 35 Relative humidity 36 37 Weight loss and machine settings Measuring moisture loss 38 39 Purpose of ventilation Water cooling 40 41 Air velocity Multi-stage or single-stage 42 43 Minor differences, major implications 4. Egg handling and quality 44 Embryonic development during egg formation 45 Cooling to physiological zero 46 47 Cooling at the breeder farm Grading and on-farm traying 48 49 Hatching egg quality Unsuitable for hatching 50 Size and uniformity 51 Hairline cracks 52 Dirty eggs 53 How should you deal with floor eggs? 55 Storage at the breeder farm 58 Humidity during storage 59 Store eggs pointed end down 60 Track and trace 61 5. Biosecurity 62 Process steps in the hatchery 63 Biosecurity zones at the hatchery 64 65 Routing at the hatchery Clean floors and walls 67 Biosecurity measures 68 Personnel and hygiene 69 Cleaning 73 Disinfection of the hatchery 75
CHAPTER 1:
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Introduction
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Fertile hatching eggs are produced with great care on a breeder farm. At the hatchery, the development of the embryos must proceed successfully to ensure a good start to the chicks’ lives so
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they subsequently achieve optimal growth, production and health. This book focuses on hatcheries for
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chickens, both laying hens and broilers.
A hatchery in 1950.
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A hatchery in 2020.
In the first half of the 20th century, hatcheries were small-scale operations and there was no clear separation between egg and meat production. Nowadays, both sectors are completely separate production chains, from pedigree breeding to processed end products. In most countries, hatcheries have grown in size and the implementation and use of automated processes has continued to increase. However, hatching essentially remains a natural process that has remained unchanged for millions of years. Despite all the automated process control, sound knowledge of the natural hatching process is vital to achieve good results from artificial incubation.
Ha tc he ry S i gnal s
Key link
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Vertical integrations In many countries, hatcheries are part of a vertically integrated system for the production of meat or consumption eggs. This means that the different links in the chain are all part of a single integration. In the case of independently operating links in the chain, the individual interests of each link weigh heavily, sometimes at the expense of
the general interest. A bonus-malus system is often used to improve results. In general, vertical integration allows for more and stricter control measures if quality problems occur.
In practice, logistic considerations sometimes result in mixing eggs and/or chicks from different sources at the hatchery, but mixed flocks will always have a poorer performance. This practice also presents a biosecurity risk.
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Various breeder/parent stock farms supply hatching eggs to a single hatchery. This hatchery then supplies the hatched chicks to various broiler or rearing farms. Hatcheries serve as a key link in the production chain. Eggs provided by different suppliers arrive in the same place and are mixed in a hatchery. Day-old chicks are subsequently distributed to different farms. A hatchery therefore acts as a pivotal link for disease control as well. Hygiene/biosecurity is therefore crucial in every link of the production chain. The hatchery managers must agree with the breeder farms and production farms on which hygiene protocols are applied.
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Breeder farm sector
Hatchery
Production sites (broilers and layers) A hatchery really plays a pivotal role in the poultry sector and is therefore very important, but vulnerable at the same time. For this reason, optimal communication between the different links is vital.
1. Intro d u c t i o n
5
How the chain works There are many steps in the process from hatching egg to day-old chick. Each step in the process has its critical points of attention. Egg collection and grading
Climate controlled egg storage and sometimes disinfection at the breeder farm
Egg transport from the breeder farm to the hatchery
Egg quality inspection
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Climate controlled egg storage at the hatchery
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Disinfection of eggs and setter loading
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Transferring eggs from the setter tray to the hatcher baskets
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Hatcher
Candling on day 18
Chick selection, sexing, vaccinations, other treatments (i.e. beak) and counting
Chick storage in an air-conditioned room
6
Transport to the broiler or rearing farm
Arrival at the poultry farm
Ha tc he ry S i gnal s
Egg Quality
Incubation is interaction
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People
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Incubation is a process where egg quality, technology and people (hatchery personnel) have equal influence on hatchability and chick quality. If any of these elements performs less well than expected, the results will be immediately visible in both hatchability and chick quality.
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Multi-stage and single-stage Hatching systems can be either multi-stage or single-stage. In single-stage incubators, a single batch of fresh eggs is set for 18 days and machine settings are adapted to meet the changing embryonic requirements with age. In multi-stage incubators, eggs from different embryonic ages are mixed. Typically, in North and Latin America and developing countries more multi-stage incubators are used, whereas in Europe single-stage incubators are more common. In some cases, even eggs for layers are placed in the setter with eggs intended for the broiler industry. Obviously, that is a far from ideal method.
Technology
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It takes more to hatch an egg than just an incubator. You need good basic material in the shape of uniform, fertile hatching eggs. The characteristics of these eggs largely depend on the type of egg (for broilers or laying hens), but also on the genetic background (breeds and lines). In addition, incubation involves certain processes that must be performed properly by skilled staff. Even though machines have been perfected and automated over the years, the human element remains an important factor in this process. After all, it is people who are responsible for ensuring smoothly running processes, and they can also intervene if things turn out differently than planned. The conditions are different at each hatchery, so there is no one-size-fits-all incubator suitable for all circumstances. Each hatchery manager works with their own settings and determines their own goals. One possible goal could be, for example, a higher than 93% hatch of fertile and less than 1% chick mortality in the first week.
Fahrenheit or Celsius? Two temperature systems are used worldwide: Fahrenheit and Celsius. This usually depends on the country, with most countries using Celsius whereas Fahrenheit is mainly used in the USA. However, in hatcheries, the most commonly used unit of temperature is Fahrenheit. Therefore, this book sometimes uses both units.
°C = (°F – 32)/1.8 or vice versa °F = (°C × 1.8) + 32
Incubator or setter? The total incubation process of about 21 days is split into two main phases: setting for 18 days and hatching for 3 days. In a hatchery the terms setter and hatcher are used, but the term incubator is also used to indicate the room where the eggs are kept during the first 18 days. In this book the terms setter and incubator are both used.
1. Intro d u c t i o n
For an easy conversion tool, scan this QR-code. All other measurements are stated in the metric system. • Distance: 1 m = 3.3 ft = 1.1 yards • Weight: 1 kg = 2.2 lbs, 1 g = 0.035 oz • Area: 1 m2 = 10.8 sqft • Ventilation: 1 m3/h = 0.59 cfm • Air velocity: 1 m/s = 3.3 fps
7
CHAPTER 2:
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The incubation process
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You first need to understand how a single egg incubates and hatches before you can understand the incubation and hatching process at a hatchery. And even then, the step to using an incubator is a giant
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one! That process is geared to the average egg and knowing that each batch contains a variation of eggs that must be taken into consideration. The greatest challenge is incubating and hatching all the
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eggs in the most optimal conditions.
How is the embryo supplied with nutrients in the egg?
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Period
Source for energy and development
Day 1 to 4
Carbohydrates from albumen and yolk as an energy source.
After day 4
Fats from the yolk (yolk is approx. 30% fat). Cholesterol and other components (fats) from the yolk create cell walls and nerves.
After day 12
Calcium from the shell for calcification of the bones. Protein for tissue formation is provided by the albumen. The energy needed is mainly provided by the yolk.
Weight changes in the egg during the incubation period
40 35 Weight proportion (%)
Unlike a mammal, the egg has to contain all the required nutrients from the moment of oviposition. The shell around the eggs allows the exchange of heat, gases and moisture. The gas exchange depends on external factors. During the incubation process, you will notice changes in the utilisation of nutrients and in the development of the different parts of the embryo.
albumen
30 25
embryo
yolk
20 sub-embryonic fluid
15 10
allantoic fluid
0 0
0
5
amniotic fluid
10 15 Incubation time (days)
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Changes that occur in the mass of the embryo, yolk and the albumen (egg white), and in the volume of the fluid structures of the developing embryo. Ha tc he ry S i gnal s
The anatomy of the hatching egg Is the yolk sac the remnant of the yolk?
It is important to know how a fertile egg is composed to understand the incubation process and to be able to assess a hatching egg.
It is not the case that the original yolk is partly used for energy and development of the embryo and that the yolk sac remains as ‘leftover’ of these processes. During the incubation process the albumen and the original yolk become more fluid with embryonic membranes and fluid compartments developing. This starts at day 3 and is visible as a ‘blood ring’ until day 11-12 when the chorion-allantoic membrane covers the whole inner eggshell membrane. In the meantime there is a continuous exchange of fluids between the various compartments. Towards the end of incubation, water is extracted and the yolk sac becomes more viscous, but by that time its content has changed a lot. The fact that it has a similar colour and is in a similar position within the egg, does not automatically mean that it is the same thing!
Air cell. The space between the shell membrane and the egg membrane. Provides oxygen for the chick’s first breaths after internal pipping. Albumen (egg white). Protects the egg yolk (buffer and anti-bacterial effect) and provides additional nutrients to the embryo.
Latebra. The column of white yolk that connects the blastodisc to the centre of the yolk (pale in fertilised eggs on an MRI-image).
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Cuticle. A layer of protein is deposited on the shell just before laying. It protects the contents of the egg and the shell by closing the pores.
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Germinal disc. The area of the egg from which the embryo begins to develop in the hen’s body after fertilisation.
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Eggshell. The outer protective layer of the egg. The shell regulates the exchange of heat, gases (CO2 and O2) and water vapour (H2O) through the pores.
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Chalazae. These cords attach the yolk in the centre of the unincubated egg.
remnants of vitelline membrane
shell membranes
chorion Embryo. The first stage of development starts in the hen’s body when the egg is produced. sero-amniotic connection Amniotic fluid. Serves to cushion the embryo and prevents dehydration.
Avascular mesoderm Vascular mesoderm Ectoderm Endoderm
yolk sac membrane
albumen
Chorion (outer membrane). Regulates the exchange of gas and protects against harmful bacteria.
White yolk. Provides nutrients for the first development phase of the embryo and has a slightly different composition than the yellow yolk. Vitelline membrane. Functions as a barrier that allows for diffusion of water and selective nutrients between the albumen and the yolk.
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Eggshell membranes. Protect the embryo from losing too much moisture and prevent entry of pathogens.
Yellow egg yolk. Acts as a source of nutrients for the embryo.
yolk Yolk sac. Supplies the embryo with nutrients.
extraembryonic coelom amnion embryo
allanto amnion
chorio allantois
Allantois. Helps with the exchange of gases at a later stage.
The various membranes and compartments in the egg containing an embryo after three days of incubation. There are many interconnections between the compartments that allow the exchange of fluids facilitated by egg turning.
2. Th e i n c u b a t i o n p ro c e s s
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Development of an embryo and external characteristics have been formed. In the second phase, a period of growth follows. During the last 3-5 days of the incubation process, the body functions mature. These include the thermoregulation ability, the immune system, the digestive system and the metabolism. How the body functions when mature depends on the conditions of incubation. Under optimal incubation conditions, all these functions will be better developed.
In the right conditions, the individual embryo develops into a chick in 21 days. There are three development stages. The first week is the differentiation phase, which already starts in the hen’s body after fertilisation. The specific tissues are formed during this phase. At this moment, the embryos are very sensitive to temperature fluctuations, jolts/vibrations and disinfectants. This phase requires a uniform embryo temperature to ensure all the embryos hatch at the same time later on. At the end of this first phase (day 10/day 11) all the organs
Day 1
Day 2
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The blood ring (area vasculosa) is complete, head turned to the right, heart beats.
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The embryo is partly lying on its left side. Head starts to move. The eye pigment becomes visible; formation of wings and legs is clearly recognisable.
Embryo takes on a C-shape, lying on its left side. The heart takes on final form with chambers (ventricles and atria). The volume of the sub-embryonic liquid is almost maximum.
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Day 4
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Day 3
The first blood islands are formed; the head and heart are recognisable. The embryo ‘floats’ on the sub-embryonic liquid. The extraembryonic membranes continue to develop.
The germinal disc grows in size and the light-coloured ring around the embryo (arrow) means that the extraembryonic membranes are developing. These membranes transport `water’ from the albumen to the yolk under the embryo (subembryonic space).
Day 8 Calcium starts to be deposited in the bones. The amnion absorbs water, so the yolk sac becomes firmer. Three rows of tail feather buds are clearly recognisable.
Day 6 Beak becomes visible. The embryo is protected in the closed amnion. The tip of the egg contains a jelly-like mass: the residues of protein (albumen). Almost all the water is now stored in the sub-embryonic cavity. The yolk has disappeared. Day 9 The amnion absorbs more fluid and increases in size. A chorioallantoic membrane covers 80% of the embryo and the yolk sac. The beak opening is visible. The maternal antibodies are mainly found in the yolk sac.
Ha tc he ry S i gnal s
Day 10
Day 11
Active, but aimless, movement of the embryo in the amnion that now has a maximum volume. The toes are completely separated.
Day 12
Leg scales appear, first feathers visible.
Day 13
Day 14
Day 15
Embryo starts to extend the head towards the air cell. Residues of the protein containing a small number of maternal antibodies are mixed with the contents of the amnion.
Movement decreases.
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Head in the yolk sac. Heat production and oxygen consumption increase exponentially. The embryo moves for longer periods. Movement stimulates bone development.
Chorioallantoic membrane surrounds the inside of eggshell. Volume of the amniotic fluid decreases. The legs are bent and albumen protein is absorbed in the yolk sac.
Day 17
Embryo’s head faces the air cell, the volume of the amnion decreases.
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Day 18 Head moves under right wing, beak towards air cell, legs over the head. Intestines move into the abdominal cavity.
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The protein is completely absorbed by the embryo. The down is fully developed.
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Day 16
The yolk sac is absorbed into the body cavity.
2. Th e i n c u b a t i o n p ro c e s s
Day 20 The yolk sac is fully retracted via the navel, the chick pierces the inner membrane and starts peeping.
Day 21 Chick breaks through the eggshell, respiratory gas exchange through the shell has stopped and the navel can close. Chick pushes itself free from the eggshell.
Source: PasReform
Day 19
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CHAPTER 3:
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Principles of artificial incubation
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For optimal incubation results, it is important to understand the processes that create the optimal conditions for the eggs and to minimise variation within a batch. Hatcheries generally specialise in
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hatching either laying hen chicks or broiler chicks.
Slow-growing broilers The egg weight of slow-growing broiler breeds is often slightly lower compared to eggs of regular broilers from parent stock of the same age. Egg quality is generally better. A decrease in hatchability due to a long storage period is therefore less. The incubation program must be adapted. This means that eggs for slow-growing and regular broilers cannot be mixed in one batch in the same incubator. At the end of the incubation period, embryos of regular broiler breeds produce more heat. The total time incubation time is also a little shorter (by 4-6 hours shorter). Embryos for slow-growing broilers are less sensitive to incubation temperatures that are too high after day 10.
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Broilers and laying hens The processes used to incubate hatching eggs for broilers and laying hens have significant differences. Eggs from broiler parent stock and laying hen parent stock can never be incubated at the same time in the same incubator, because both types of egg place completely different demands on the incubation program. Hatching eggs for layer hen production contain relatively less yolk. Consequently, there is less energy available to the embryo for growth and heat production. However, the optimal embryo temperature during incubation is identical for laying hen embryos and for broiler embryos (37.8°C/100°F). Hatching eggs for laying hen chicks should therefore be incubated at a higher machine temperature.
Ha tc he ry S i gnal s
Broiler hatchery
Scale of hatchery
Layer hen hatchery
Relatively large: more than 100 large incubators, 2 million day-old chicks a week.
Relatively small: fewer incubators, incubators are smaller. Often 200,000 to 400,000 female chicks a week.
approx. 21 days.
approx. 21.5 days.
Broiler embryos produce more heat in the second half of the incubation process.
Higher incubation temperature, as these embryos produce less heat than broiler embryos.
Breeding program: relative humidity
Variations in eggshell quality and therefore moisture loss increase with older parent stock. The variation is greater than with laying hens.
The eggshell is firmer and thicker so less moisture is evaporated through the shell. The hatchery manager must assess the chicks well and reduce the relative humidity in the incubator if the chicks have a large yolk sac (thick belly).
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Smaller and more uniform (which is an important selection criterion for table eggs).
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Egg size and shape Larger and less uniform (with a relatively larger yolk).
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Incubation time Incubation settings: temperature
Important for a uniform broiler flock, but more difficult to achieve.
It is easier to maintain uniform weight in the parent stock for more uniform egg weight.
Eggshell quality
This is a less important selection criterion and therefore thinner.
A thick eggshell is a selection criterion for table eggs. This sometimes makes it more difficult to attain sufficient weight loss (often chicks with thick bellies).
Sexing
Males and females are not sexed, although this differs per Males and females are sexed at the hatchery. The males country. If broiler chicks are to reach a slaughter weight of are culled. In-ovo sexing is now also used, to avoid the more than 2 kg, they are often sexed since hens deposit practice of culling day-old males. more abdominal fat as they become heavier. And males grow more efficiently.
Treatments
No treatments. Vaccinations.
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Uniformity
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Occasional beak treatment. Vaccinations.
Difference in heat production between hatching eggs for laying hens and broilers
Differences between breeds Eggs from different breeds/brands have different quantities of yolk and eggshell properties. Two important, related eggshell properties are permeability (via membranes and pores) and heat transfer (ability to absorb/release heat). Permeability is important for gas exchange and evaporation and therefore heat loss. The hatchery manager must take these properties into account when incubating hatching eggs from different breeds. The breeding company will supply a guide for each breed detailing the specific properties so the incubation program can be set accordingly.
3. P r in c i p l e s o f a r t i f i c i al i n cu bati o n
Heat production (mW/egg)
180 broiler
160 140 120
layer
100 80 60 40 20 0
0
2
4
6 8 10 Incubation time (days)
12
14
16
18
The yolk/white ratio depends on the type of bird (broiler/laying hen), the age of the parent stock and the size of the egg in a batch of hatching eggs. The quantity of yolk in the egg largely determines how much heat is produced. This is why broiler embryos produce more heat than those of layer hens.
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Eggshell temperature is key
LOOK-THINK-ACT
Which measurement is correct?
7 day weight (g)
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Effect of egg shell temperature on hatching results
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Measure the eggshell temperature at the equator of the egg and not at the top, otherwise you will measure the temperature near the air cell. Air has an insulating effect, so you could measure a different value than the actual embryo temperature. If you do this manually, don’t wait too long to measure: after opening the door, the eggshell temperature will drop.
Because it is difficult to measure the embryo temperature, the eggshell temperature (EST) is measured. The EST differs approx. 0.1-0.2°C (0.20.4°F) from the embryo temperature, depending on the stage of incubation. At the start of incubation, when the eggs must be warmed, the embryo temperature is lower than the eggshell temperature. In a further stage of embryonic development, the embryo produces more heat and the embryo temperature will be higher than the EST. The heat that the embryo produces has to be removed. The same applies to the relationship between the eggshell temperature and the temperature in the incubator. Many other influences play a role, such as air velocity and evaporative heat. The eggshell temperature is therefore not the same as the air temperature in the incubator! In practice, each hatchery uses its own program. The eggshell temperatures affect the body weight and feed conversion rate of the day-old chick posthatch. The temperature in the incubator is often already reduced a long time prior to transfer of the eggs, otherwise the chick embryos could overheat between day 14 and day 18. At the end of the incubation period, the embryo temperature can exceed 40°C (104°F). And, at some locations, the variation in embryo temperature can increase by more than 2-3°C (4-5°F), depending on the position in the incubator, especially in places with little air movement and close to the spray nozzles.
99°F 37.2°C
99.5°F 37.5°C
100°F 100.5°F 101°F 101.5°F 37.8°C 38.0°C 38.3°C 38.6°C
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7 day mortality (%)
Eggshell temperature
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If the incubation temperatures are persistently too high or too low, there will be higher mortality in the first week and a lower chick weight after a week. The chick yield (chick weight/egg setting weight) is slightly higher at a lower incubation temperature, but within a week this positive effect has disappeared.
Which temperature measurement is corret? T=? T=? T=?
Heat production is highest towards the end of incubation. Any mistakes in temperature measurement must be avoided. After day 14, you should take a few temperature readings on each egg to avoid wrong measurements. Low temperatures may be caused by insufficient contact of the embryo with the eggshell; the highest reading is the correct value. The air cell is also getting larger and may have shifted a little to the left or right (incorrect turning angle?). 30
Maintain a constant embryo temperature of 37.8°C (100°F). Check the temperature using an infrared thermometer. Make sure the tip of the thermometer is flat against the equator of the egg.
Ha tc he ry S i gnal s
Embryo temperature during the incubation process (°F/°C)
Incubation temperature Based on average values, embryonic development is optimal during the first 18-19 days at an embryo temperature of 37.8°C (100°F). After internal, and then external, pipping, the temperature of the embryos may gradually increase from day 20 to 39°C (102°F). As a rule of thumb, aim for a range in which 95% of the eggs/day-old chicks are no more than 1% below or above the optimal value: 1% of 37.8°C rounds off to 0.4°C. More than 95% of the eggs should therefore be in the range between 37.4-38.2°C. Note: this applies to the Celsius scale. At Fahrenheit you can stick to: between 99.3 and 100.7°F.
Optimal
Max
99.3 / 37.4
100.0 / 37.8
100.8 / 38.2
After pipping, day 20
101.5 / 38.6
102.2 / 39.0
102.9 / 39.4
Dry chick
103.1 / 39.5
104.0 / 40.0
104.9 / 40.5
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Day 1-19
This thermal image shows that the eggs in the centre of the setter tray are much warmer than the eggs at the sides. During incubation, the aim is to create the most uniform possible temperature in the whole incubator. However, the temperature can vary between different parts of the incubator. This is caused by different air velocities and using humidification sprayers.
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Variation inside the incubator There are always some cold spots and hot spots in an incubator. Cold spots occur in places such as close to the floor, the walls, the point where fresh air reaches the eggs first and around the sprayer or humidifier. Cold spots at the start of the incubation process, and hot spots at the end of the incubation process are places where there is generally little airflow. Some brief variations are not usually an immediate cause for concern. In natural conditions, the hen also occasionally leaves the nest to eat or drink towards the end of the brooding process. Prolonged deviations from optimal conditions may negatively affect embryonic development (and uniformity). Ensure proper incubator maintenance to avoid structural deviations.
Min
During the maturation stage (approx. from day 16), the embryo can respond slightly to the ambient temperature. If the temperature is too low, the heart rate decreases so the metabolic heat produced by the embryo is not released through the eggshell, but stays ‘inside’ the egg, with the embryo. The opposite also occurs: the embryo responds to ‘feeling’ too hot by increasing its heart rate so that more blood flows along the eggshell. This releases heat to the environment around the egg and allows a higher intake of oxygen. 3. P r in c i p l e s o f a r t i f i c i al i n cu bati o n
The most important thing is to maintain a constant, uniform temperature for all the eggs, particularly at the start of incubation. The ventilation is reduced to an absolute minimum (air inlets closed) to ensure the most uniform possible temperature in all the eggs and prevent cold air flowing into the incubator. If the air used to ventilate can be properly conditioned (pre-heated) this is not such a problem. 31
Index Packing 47 Paper egg flats 47, 146 Parent stock age 97 170 Pasgar score Personnel 69 Physiological zero 45, 46 Pipping 136, 137 Pipping height 151 151 Pipping line Placing chicks 188 Planning 9 Plastic tray 47 Point setting 60 Preparation 98 Pre-warming 100 Pull time 138, 140 47, 146 Pulp tray 14, 166 Red hocks Relative Humidity (RH) 36, 37, 105 19, 157, 158 Residual yolk/yolk sac Routing 65 Scoring system 169, 170 162 Selection criteria Setter trays 82 94, 99 Setting Sexing 173 Signals concept 13 7, 42, 43 Single-stage Slow-growing broilers 28 Spectroscopy 123 SPIDES 58, 89 Storage (chicks) 179 58, 76, 84 Storage (eggs) Storage conditions (eggs) 58, 59, 85 86 Storage duration Take-off table 161 Temperature 25 46, 78 Temperature development Temperature requirements 25 32 Temperature settings Temperature variation 31, 32 Tona score 169 61 Track and trace Transfer 114, 126 Transition 102 Transport 144 Transport (chicks) 180 Transport (eggs) 76, 126 Transport conditions 80 Trolley cover 80 Turning 88, 107-109 Unhatched eggs 141, 142 Uniformity 12, 27, 31, 51 Urates 150 Vaccination 120-122, 176, 177 Variation 12, 27, 31, 51 Vent sexing 173 Ventilation 34, 39 Ventilation (transport) 182 Washing 56 Weight loss 27, 37, 38 Wet bulb temperature 78, 79 Yolk Free Body Mass (YFBM) 159 Yolk sac/residual yolk 19, 157, 158
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Embryonic development 20, 21, 45, 95 Employees 71, 72 137 External pipping Fahrenheit 7 Feather sexing 174 Feathering 165 Filling 99, 101 54, 55 Floor eggs Floor quality 67 Fluff 134, 139 Formalin 75, 91, 92, 93 Fumigation 91 26 Gas exchange Gender reversal 125 Hatch moment 139 Hatch of fertile 119 118 Hatch of set Hatch of transferred 119 134 Hatch peak Hatch window 138 Hatcher baskets 131, 144 8-10 Hatchery manager Hatching 132 19 Hatching egg Hatching systems 143 Heat distribution 106 25, 33, 39,181 Heat production Heating 102 189 House inspection Humidification 103, 134 Humidity 59, 134 134 Humidity peak Hygiene 53, 69, 128, 130, 187 31 Incubation temperature Infection pressure 152 Infertile 112, 115-117 11, 12 Information exchange In-ovo sexing 123 120, 121, 122 In-ovo vaccination Integration 5 Internal pipping 136 183 International transport Jolts/vibrations 81 Key indicators (KPI) 118 Laying date 97 Laying hens 29 Legs 166 Litter 147 Logistics 82 Long storage 87 Long transport 185 Measuring 34, 38, 154 Meconium 153 Mixing 95 Moisture loss 27, 37, 38 Monitoring 110, 111 Mortality 190 Multi-stage 7, 42, 43 Natural brooding 22, 23 Navel 163 On-farm hatching 145 On-farm traying 48 Origin 96 Oxygen (O2) 39
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Abnormalities 76, 168, 171 Air cell 38, 49, 85 133 Air temperature Air velocity 41, 101 Airflow 102 Airport 184 Altitude 41 189 Arrival check Artificial incubation 22, 23 Aspergillus 75, 93, 142, 149 Bacterial load 53 Bangers 90 Beak 167 Belly 164 Biomarkers 124, 125 Biosecurity 62 Biosecurity zones 64, 65 Breakout 113, 129 Breeds 29 Broilers 29 Calibration 98 112, 113, 115-117 Candling 35, 39, 104, 159, 181 Carbon dioxide (CO2) 181 Cargo area climate Celsius 7 Chick delivery 186 159, 160 Chick length Chick quality 148 154 Chick temperature Chick transport 178 Chick weight 159 155 Chick yield Cleaning 73, 74 101 Climate conditions Cloaca 163 Cloaca sexing 173 175 Colour sexing Condensation 17, 40, 59, 77, 80, 100, 133 77 Condensation point Cooling 40, 46, 47, 102, 106 Cracks 52 15 Critical batches Critical locations 15 Critical moments 16, 17 Dew point 77 Dirty eggs 50, 53 Disinfectants 93 Disinfection 57, 63, 75, 90-93 Downgraded chicks 172 Dry bulb temperature 78, 79 Drying off 156 Drying out 156 Early feeding 143, 153, 157 Early mortality 46 Egg grading 48 Egg handling 44, 49 Egg inspections 83 Egg quality 44, 50 Egg shape 49 Eggshells 49, 149, 150 Egg size 49, 51, 97 Egg weight 49, 51, 97 Eggshell temperature 30, 45 Embryo position 135
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