Ce diaporama a bien été signalé.
Nous utilisons votre profil LinkedIn et vos données d’activité pour vous proposer des publicités personnalisées et pertinentes. Vous pouvez changer vos préférences de publicités à tout moment.
Egg Shell
Egg Losses
 Poor egg shell quality is a huge
hidden cost to egg producers.
 More than 10% of eggs produced in
the hen ho...
Cont. …
 The first 2-5%, they are lost simply due to form
which may be:
– Shell less
– Cracked or broken to the extent th...
Cont. …
 Egg producers estimate their egg
losses as the first 2-5% whom are
uncollectible eggs due to poor shell
quality....
Egg Structure
The fertile egg is highly complexed
reproductive cell and is a tiny center
of life, where initial developmen...
Cont. …
Most of the commercial eggs are
infertile.
Cont. …
Cont. …
76%
12%
10%
2%
Egg Contents
Water Protein Lipids Minerals - Vitamins - CHO
Egg Shell Structure
Functions:
1. Protecting the contents of the egg from the microbial and physical
environment.
2. Contr...
Eggshell Composition
1. Calcium carbonate:94-97%
– The calcium content of the eggshell is approximately 1.7-2.5g.
2. Phosp...
Cont. …
 There are about 8000 microscopic
pores on the shell.
 The outer surface of the shell itself
consists of a mucou...
Cont. …
Shell Quality
The aesthetic quality of the egg shell relates to the quality
factors which one can observe; such as:
1. Sou...
Cont. …
However, for commercial layer and breeder operations, shell
quality means:
1. Increased shell thickness
2. Increas...
Egg Shell Quality Defects
Shell Quality Defects
 Eggshell quality defects are obvious by direct external
observation or by candling.
 They are imp...
Shell Quality Defects
1. Misshaped Eggs
2. Sandpaper or Rough Shelled Eggs
3. Soft, Weak or Shell less Eggs
4. Dirty and G...
1- Misshaped Eggs
Description
 Misshapen eggs are those whose shells differ
obviously from the smooth, ‘normal’ shape.
 ...
Cont. …
Incidence
 Normally, up to 2% of production is downgraded due to these
faults.
 They are often produced by pulle...
Cont. …
Cause Control
Immature shell gland
• Delay onset of sexual maturity 1 to 2 weeks by controlled
feeding during rear...
2- Sandpaper or Rough Shelled Eggs
Description
 The terms ‘sandpaper shells’ and ‘rough
shells’ refer to eggs with rough-...
Cont. …
Incidence
 The incidence is normally less than 1% of total production.
 It may be higher in:
1. Some strains of ...
Cont. …
Cause Control
Diseases, e.g. infectious bronchitis,
infectious laryngotracheitis or avian
encephalomyelitis
• Foll...
Cont. …
Another cause:
 In some cases, two eggs may be in the shell gland at the same
time which can cause a form of roug...
3- Soft, Weak or Shell less Eggs
Description
 Eggs with very thin shells, or no shell at
all around the shell membrane.
...
Cont. …
Incidence
 The incidence of these eggs varies from about 0.5 to 6%.
 They are commonly produced by:
1. Pullets c...
Cont. …
Cause Control
Immature shell gland
• Delay onset of sexual maturity 1 to 2 weeks by
controlled feeding during rear...
Cont. …
Cause Control
Saline water
• Desalinate, dilute or do not use drinking water
containing problem levels of salts.
D...
Cont. …
Another causes:
 If an egg is retained in the shell gland for too long;
– The next ovulation takes place at the u...
4- Dirty and Glazed Shells (Stained Eggs)
Description
 All or part of the egg shell may become
stained by various substan...
Cont. …
Incidence
 The incidence of stained eggs varies, partly because stains
may be caused by a variety of substances.
...
Cont. …
Cause Control
Water stains
• Minimize roof condensation, which can drip onto eggs, by
providing adequate shed vent...
Cont. …
Cause Control
Sanitizers used in egg washing
• Make sure that sanitizers in washing solutions are
properly dissolv...
Cont. …
Cause Control
Faecal contamination
• Keep nest boxes supplied with clean nesting material.
• Maintain proper hygie...
Body Checks
Description
 The shells are marked by grooves and
ridges “checks”.
 They are usually at the ends of the egg,...
Cont. …
Cause
 Checks are the result of repairs to damage caused by stress or
pressure when the egg is in the shell gland...
Cont. …
Incidence
 The percentage of body-checked eggs increases with flock
age: at 35 weeks it can be up to 1%; at 60 we...
Cont. …
Cause Control
Ageing of bird • Keep flock age as low as economically possible.
Keep flock age as
low as economical...
Cracked Eggs
 Egg shells can easily be damaged after the egg is laid.
 Cracking is one of the most common reasons for
do...
Gross Cracks
Description
 The term ‘gross cracks’ refers to large
cracks and holes, which usually result in
a broken shel...
Cont. …
Incidence
 The incidence of gross cracks increases with the age of the
hen.
 It ranges from 1 to 5% of total pro...
Cont. …
Cause Control
Reduced shell strength due to:
Ageing • Keep flock age as low as economically possible.
Poor nutriti...
Cont. …
Cause Control
High shed temperatures
• Control temperatures by using foggers, fans, roof
sprinklers, white roofs, ...
Cont. …
Cause Control
Rough handling
• Do not collect eggs in wire baskets.
• When stacking fillers of eggs, place one emp...
Hairline Cracks
Description
 They very fine cracks, usually run
lengthwise along the shell.
 They are difficult to detec...
Cont. …
Incidence
 The incidence of this problem varies with flock age, but is
usually 1 to 3% of total production.
Cont. …
Cause Control
Reduced shell strength due to:
Ageing • Keep flock age as low as economically possible.
Poor nutriti...
Cont. …
Cause Control
High shed temperatures
• Control temperatures by using foggers, fans, roof
sprinklers, white roofs, ...
Cont. …
Cause Control
Rough handling
• Do not collect eggs in wire baskets.
• When stacking fillers of eggs, place one emp...
Star Cracks
Description
 Star cracks are fine cracks radiating
outwards from a central point of
impact, which is often sl...
Cont. …
Incidence
 The incidence varies with flock age but is usually 1 to 2% of
total production.
Cont. …
Cause Control
Reduced shell strength due to:
Ageing • Keep flock age as low as economically possible.
Poor nutriti...
Cont. …
Cause Control
Mechanical
damage caused
by birds’ beaks
and toenails
Make sure that:
• The cage floor is not too ri...
Flat-sided Eggs
Description
 Eggs are said to be flat-sided when part
of the shell is flattened or indented.
Cont. …
Incidence
 Flat-sided eggs normally make up less than 1% of total
production.
 They are most commonly produced b...
Cont. …
Cause Control
Disease; traditionally linked with infectious
bronchitis
• Follow an effective vaccination program.
...
Pimples
Description
 Pimples are small lumps of calcified
material on the egg shell.
 Some can be broken off easily with...
Cont. …
Incidence
 An incidence of about 1% of total production is common.
Cont. …
Cause Control
Thought to be caused by foreign material in the oviduct, which may be associated with:
Ageing of bir...
Pinholes
Description and
 Pinholes, or very small holes in the egg
shell.
Cont. …
Incidence
 usually affect less than 0.5% of total production.
Cont. …
Cause Control
May result from faulty laying down of the egg shell or from pimples being knocked off
the shell. Bot...
Mottled or Glassy Shells
Description
 When parts of the egg shell are
translucent, it appears mottled or
glassy. Such she...
Cont. …
Description
 When parts of the egg shell are translucent, it appears
mottled or glassy. Such shells can also be t...
Cont. …
Cause Control
Failure of the egg shell to dry out quickly after laying, which is made worse by:
High humidity in t...
Fungus or Mildew on Shells
Description
 Eggs affected by a fungus may have a
green coating of powdery material or a
black...
Cont. …
Incidence
 This defect should not occur under good management.
 Any incidence is unacceptable.
Cont. …
Cause Control
Poor hygiene during handling,
storage and transport
• Do not use soiled egg-handling equipment.
• Re...
Cage Marks Shells
Description
 'Cage marks' is the term used to refer to
dirty marks, dirty lines or translucent
lines on...
Cont. …
Incidence
 In well-managed flocks, the incidence of this problem should
be under 5%.
Cont. …
Cause Control
Dirty marks or lines are due to:
Rusty or dirty wires in the
cage fl oor or roll-out trays
• Check w...
Cont. …
Cause Control
Translucent lines result when the shell fails to dry out quickly after laying, which is
made worse b...
Fly Marks Shells
Description
 Fly marks are caused by flies leaving
droppings on the egg shell.
Cont. …
Incidence
 This defect should not occur under good management.
 Any incidence is unacceptable.
Cont. …
Cause Control
Eggs exposed to large numbers
of flies
• Control flies on the farm by maintaining a high
level of hy...
Prochain SlideShare
Chargement dans…5
×

Eggshell_Quality_and_Defects

"عسى ان يكون علما ينتفع به:
Poultry eggshell
egg shell quality
cracked egg
mishapen egg

Livres associés

Gratuit avec un essai de 30 jours de Scribd

Tout voir
  • Soyez le premier à commenter

Eggshell_Quality_and_Defects

  1. 1. Egg Shell
  2. 2. Egg Losses  Poor egg shell quality is a huge hidden cost to egg producers.  More than 10% of eggs produced in the hen house are uncollectible or broken before intended use.
  3. 3. Cont. …  The first 2-5%, they are lost simply due to form which may be: – Shell less – Cracked or broken to the extent that they are not suitable for collection.  Another 3-8% is lost during: – Collection – Moving through the belts – Cleaning – Packing – Transportation to the end user
  4. 4. Cont. …  Egg producers estimate their egg losses as the first 2-5% whom are uncollectible eggs due to poor shell quality.  The economic losses for the breeders will be even more due to reduced hatchability and chick livability.  Therefore, every effort must be directed towards improving shell quality and reducing egg breakage.
  5. 5. Egg Structure The fertile egg is highly complexed reproductive cell and is a tiny center of life, where initial development of embryo takes place.
  6. 6. Cont. … Most of the commercial eggs are infertile.
  7. 7. Cont. …
  8. 8. Cont. … 76% 12% 10% 2% Egg Contents Water Protein Lipids Minerals - Vitamins - CHO
  9. 9. Egg Shell Structure Functions: 1. Protecting the contents of the egg from the microbial and physical environment. 2. Controlling the exchange of water and gases. Weight 5-6 gm 10% of total egg weight Thickness: 300-350 micrometes. Breaking strength >30N
  10. 10. Eggshell Composition 1. Calcium carbonate:94-97% – The calcium content of the eggshell is approximately 1.7-2.5g. 2. Phosphorus:0.3% 3. Magnesium:0.2% 4. Sodium, Potassium, Manganese, Iron and Copper: traces 5. Organic matter:< 2%, it is consisted of: 1. Matrix proteins • They are mixture of proteins and polysaccharides rich in sulphated molecules. • They are critically important in determining the egg shell structure and serves as foundation for the deposition of calcium carbonate. 2. Shell pigment.
  11. 11. Cont. …  There are about 8000 microscopic pores on the shell.  The outer surface of the shell itself consists of a mucous coating (cuticle) which is deposited on the egg just prior to the lay.  This proteinous covering helps to protect the interior content of the egg from bacterial penetration through the shell.
  12. 12. Cont. …
  13. 13. Shell Quality The aesthetic quality of the egg shell relates to the quality factors which one can observe; such as: 1. Soundness of the shell. 2. Shape of the shell. 3. Colour of the shell.
  14. 14. Cont. … However, for commercial layer and breeder operations, shell quality means: 1. Increased shell thickness 2. Increased shell breaking strength To: 1. Reduce number of cracked eggs 2. Increase number of saleable/ hatching eggs 3. Higher number of viable day old chicks.
  15. 15. Egg Shell Quality Defects
  16. 16. Shell Quality Defects  Eggshell quality defects are obvious by direct external observation or by candling.  They are important for evaluation for the producer and consumer.  It is also the main criteria for selecting hatching eggs.
  17. 17. Shell Quality Defects 1. Misshaped Eggs 2. Sandpaper or Rough Shelled Eggs 3. Soft, Weak or Shell less Eggs 4. Dirty and Glazed Shells or Stained Eggs 5. Body Checks 6. Cracked Eggs 1. Gross Cracks 2. Hairline Cracks 3. Star Cracks 7. Flat-sided Eggs 8. Pimples 9. Pinholes 10. Mottled or Glassy Shells 11. Fungus or Mildew on Shells 12. Cage Marks Shells 13. Fly Marks Shells
  18. 18. 1- Misshaped Eggs Description  Misshapen eggs are those whose shells differ obviously from the smooth, ‘normal’ shape.  They include eggs with shells marred by flat sides or body checks (ribs or grooves), and eggs that are too large or too round.
  19. 19. Cont. … Incidence  Normally, up to 2% of production is downgraded due to these faults.  They are often produced by pullets coming into lay, or hens late in lay.
  20. 20. Cont. … Cause Control Immature shell gland • Delay onset of sexual maturity 1 to 2 weeks by controlled feeding during rearing. Defective shell gland • Cull birds which persistently produce such eggs. Diseases, e.g. infections bronchitis • Follow an effective vaccination program Stress, e.g. frights and disturbances To avoid frightening birds; • Minimize human activity in and around the shed. • Increase shed security to stop other birds and animals entering the shed. Crowding • Avoid overstocking.
  21. 21. 2- Sandpaper or Rough Shelled Eggs Description  The terms ‘sandpaper shells’ and ‘rough shells’ refer to eggs with rough-textured areas, often unevenly distributed over the shell.
  22. 22. Cont. … Incidence  The incidence is normally less than 1% of total production.  It may be higher in: 1. Some strains of bird. 2. Birds in early lay.
  23. 23. Cont. … Cause Control Diseases, e.g. infectious bronchitis, infectious laryngotracheitis or avian encephalomyelitis • Follow effective vaccination program. Defective shell gland • Cull such birds. Disturbances at the time a hen is due to lay can cause the egg to be held over for another day • Minimize activities which create disturbances in and around the shed. • Increase shed security to stop other birds and animals entering the shed. Incorrect or changes in lighting programme • There should not be sudden increases in day length as pullets come into lay, or lighting changes during lay. Water shortages • Make sure that the water supply is adequate, that there are no blockages in water lines and that drinkers are functioning property.
  24. 24. Cont. … Another cause:  In some cases, two eggs may be in the shell gland at the same time which can cause a form of rough shelled egg often referred to as a ‘target’ or ‘thumb-print’ type.
  25. 25. 3- Soft, Weak or Shell less Eggs Description  Eggs with very thin shells, or no shell at all around the shell membrane.  They look unattractive and are highly susceptible to damage.
  26. 26. Cont. … Incidence  The incidence of these eggs varies from about 0.5 to 6%.  They are commonly produced by: 1. Pullets coming into lay, particularly by birds that have matured early. 2. Older birds, especially those which are nearing the end of the laying period, having produced a high output of eggs.
  27. 27. Cont. … Cause Control Immature shell gland • Delay onset of sexual maturity 1 to 2 weeks by controlled feeding during rearing. Defective shell gland • Cull birds which persistently produce such eggs. Disturbances causing eggs to be laid before calcification of the shell is complete • Minimize activities which create disturbances in and around the layer shed. • Increase shed security to stop other birds and animals entering the shed. Poor nutrition • Make sure that birds’ nutrient intake is correct (particularly regarding calcium and vitamin D3). • Mixed feed should be handled carefully so that the different components do not separate out. • This particularly needs to be checked when augers and automatic feeding systems are used.
  28. 28. Cont. … Cause Control Saline water • Desalinate, dilute or do not use drinking water containing problem levels of salts. Diseases, e.g. infectious bronchitis and eggdrop syndrome • Follow effective vaccination programs where available.
  29. 29. Cont. … Another causes:  If an egg is retained in the shell gland for too long; – The next ovulation takes place at the usual time but before the previous egg is laid. – The second egg may spend less time than normal in the shell gland and the result is a soft or shell-less egg. – In such cases, a hen may not lay an egg on one day, but may lay both a coated and a soft-shelled egg on the next.
  30. 30. 4- Dirty and Glazed Shells (Stained Eggs) Description  All or part of the egg shell may become stained by various substances, e.g. blood, faeces.
  31. 31. Cont. … Incidence  The incidence of stained eggs varies, partly because stains may be caused by a variety of substances.  Smears of blood are more common on eggs from pullets in early lay.
  32. 32. Cont. … Cause Control Water stains • Minimize roof condensation, which can drip onto eggs, by providing adequate shed ventilation. • Eliminate drips from faulty misting nipples and drinker lines. Blood from a prolapsed cloaca, cannibalism or vent picking • Do not allow pullets to become over-fat, as the incidence of prolapse is greater in fat birds. • There should not be sudden large increases in day length as pullets come into lay. • Regularly clean cage bottoms and roll-out trays. • Clean belt pick-up systems.
  33. 33. Cont. … Cause Control Sanitizers used in egg washing • Make sure that sanitizers in washing solutions are properly dissolved and used at the correct concentrations. Grease and oil stains • Do not allow eggs to become contaminated by lubricants on rollers in packing systems. Certain drugs produce mottled shells or white shells in breeds that normally lay brown eggs. The drug chlortetracycline produces yellow shells. • Do not feed to layers or pullets just before lay. • Follow correct procedures for medication, including not feeding the medication for the required withholding time before eggs are collected, to prevent residues.
  34. 34. Cont. … Cause Control Faecal contamination • Keep nest boxes supplied with clean nesting material. • Maintain proper hygiene, follow effective vaccination programmes and, when necessary, use appropriate medication to keep birds free of diseases which cause enteritis. • Feed should not contain high levels of ingredients causing loose or sticky droppings, such as molasses and high- tannin sorghums.
  35. 35. Body Checks Description  The shells are marked by grooves and ridges “checks”.  They are usually at the ends of the egg, especially the pointed end.  Checks at the middle, or ‘waist’, often completely encircle the egg.
  36. 36. Cont. … Cause  Checks are the result of repairs to damage caused by stress or pressure when the egg is in the shell gland.  This stage of development usually occurs in the last hours of the light period or the first half of the dark period.
  37. 37. Cont. … Incidence  The percentage of body-checked eggs increases with flock age: at 35 weeks it can be up to 1%; at 60 weeks it can be 9%. Complications  With table eggs, it creates an increased risk of breakage en route to the consumer and lowers the utility value of the egg.  With hatching egg, it is major factor contributing to cracks during storage and results in lower hatchability.
  38. 38. Cont. … Cause Control Ageing of bird • Keep flock age as low as economically possible. Keep flock age as low as economically possible. • Minimize human activity in and around the layer shed, particularly during the critical period of the last few hours of the light period and the first half of the dark period. • Increase shed security to stop other birds and animals entering the shed. Incorrect lighting programme Avoid using lighting program that keep birds active during the critical period. Where possible, light periods should not be longer than 15 hours. Do not use lighting program which allow for a ‘midnight snack’. Crowding • Avoid overstocking, particularly as birds become older. Disease • Make sure that layer stock come from parent stock vaccinated against infectious bursal disease.
  39. 39. Cracked Eggs  Egg shells can easily be damaged after the egg is laid.  Cracking is one of the most common reasons for downgrading.  It may be due either to an inadequate egg shell being laid or to poor handling which may occur during collection, grading or transportation.
  40. 40. Gross Cracks Description  The term ‘gross cracks’ refers to large cracks and holes, which usually result in a broken shell membrane.
  41. 41. Cont. … Incidence  The incidence of gross cracks increases with the age of the hen.  It ranges from 1 to 5% of total production.
  42. 42. Cont. … Cause Control Reduced shell strength due to: Ageing • Keep flock age as low as economically possible. Poor nutrition • Make sure that the birds’ nutrient intake is correct (particularly regarding calcium and vitamin D3). • Mixed feed should be handled carefully so that the different components do not separate out. • This particularly needs to be checked when augers and automatic feeding systems are used. Saline water • Desalinate, dilute or do not use drinking water containing problem levels of salts. Diseases such as infectious bronchitis • Follow an effective vaccination programm.
  43. 43. Cont. … Cause Control High shed temperatures • Control temperatures by using foggers, fans, roof sprinklers, white roofs, insulation and good ventilation. Mechanical damage caused by birds’ beaks and toenails • Control egg eating by the birds. • Make sure that birds do not have access to eggs in roll-out trays. Use cages designed to prevent access. • Reduce damage caused by the birds’ toenails. • The slope and construction of the cage floor should allow the eggs to move freely to the roll-out tray. Infrequent egg collection • Collect eggs at least twice a day.
  44. 44. Cont. … Cause Control Rough handling • Do not collect eggs in wire baskets. • When stacking fillers of eggs, place one empty filler at the bottom of the stack, and a full one directly on top of it. This double bottom layer supports the weight of the stack better. • Avoid stacking fillers of eggs more than six high. • Pick up and carry stacks with care. • Place large eggs on top fillers in a stack. • Reduce the severity of impacts during mechanical handling by: • Cushioning metal egg guides; • Keeping egg roll-out angles between 7 and 8°; • Minimizing the number of rows of eggs being fed onto cross- conveyor belts at any one time. • Educate staff to handle eggs with care during collection and packing.
  45. 45. Hairline Cracks Description  They very fine cracks, usually run lengthwise along the shell.  They are difficult to detect, candling efficiency needs to be maximized.  Their presence in fresh eggs can be revealed by careful squeezing or tapping.  They are the most difficult to identify, particularly in very fresh eggs.  Hairline cracks are often caused by an egg colliding with an inflexible surface.
  46. 46. Cont. … Incidence  The incidence of this problem varies with flock age, but is usually 1 to 3% of total production.
  47. 47. Cont. … Cause Control Reduced shell strength due to: Ageing • Keep flock age as low as economically possible. Poor nutrition • Make sure that the birds’ nutrient intake is correct (particularly regarding calcium and vitamin D3) • Mixed feed should be handled carefully so that the different components do not separate out. • This particularly needs to be checked when augers and automatic feeding systems are used. Saline water • Desalinate, dilute or do not use drinking water containing problem levels of salts. Diseases such as infectious bronchitis • Follow an effective vaccination program.
  48. 48. Cont. … Cause Control High shed temperatures • Control temperatures by using foggers, fans, roof sprinklers, white roofs, insulation and good ventilation. Mechanical damage caused by birds’ beaks and toenails Make sure that: • the cage floor is not too rigid. • the slope of the floor is just enough to allow eggs to roll out. • roll-out trays cushion the eggs as they come to rest against the edge of the tray. Infrequent egg collection • Collect eggs at least twice a day.
  49. 49. Cont. … Cause Control Rough handling • Do not collect eggs in wire baskets. • When stacking fillers of eggs, place one empty filler at the bottom of the stack, and a full one directly on top of it. • This double bottom layer supports the weight of the stack better. • Avoid stacking fillers of eggs more than six high. • Pick up and carry stacks with care. • Place large eggs on top fillers in a stack. • Reduce the severity of impacts during mechanical handling by: • cushioning metal egg guides. • keeping egg roll-out angles between 7 and 8°. • minimizing the number of rows of eggs being fed onto cross-conveyor belts at any one time. • Educate staff to handle eggs with care during collection and packing.
  50. 50. Star Cracks Description  Star cracks are fine cracks radiating outwards from a central point of impact, which is often slightly indented.
  51. 51. Cont. … Incidence  The incidence varies with flock age but is usually 1 to 2% of total production.
  52. 52. Cont. … Cause Control Reduced shell strength due to: Ageing • Keep flock age as low as economically possible. Poor nutrition • Make sure that the birds’ nutrient intake is correct (particularly regarding calcium and vitamin D3) Mixed feed should be handled carefully so that the different components do not separate out. • This particularly needs to be checked when augers and automatic feeding systems are used. Saline water • Desalinate, dilute or do not use drinking water containing problem levels of salts. Diseases such as infectious bronchitis • Follow an effective vaccination program. High shed temperatures Control temperatures by using foggers, fans, roof sprinklers, white roofs, insulation and good ventilation.
  53. 53. Cont. … Cause Control Mechanical damage caused by birds’ beaks and toenails Make sure that: • The cage floor is not too rigid. • The slope of the floor is just enough to allow eggs to roll out. • Roll-out trays cushion the eggs as they come to rest against the edge of the tray. Infrequent egg collection • Collect eggs at least twice a day. Rough handling • Do not collect eggs in wire baskets. • Reduce the severity of impacts during mechanical handling by: • cushioning metal egg guides. • keeping egg roll-out angles between 7 and 8°. • minimising the number of rows of eggs being fed onto cross-conveyor belts at any one time. • Educate staff to handle eggs with care during collection and packing.
  54. 54. Flat-sided Eggs Description  Eggs are said to be flat-sided when part of the shell is flattened or indented.
  55. 55. Cont. … Incidence  Flat-sided eggs normally make up less than 1% of total production.  They are most commonly produced by pullets in early lay and may be the result of double ovulation or being held over an extra day in the shell gland.  Incidence can vary with the strain of bird.
  56. 56. Cont. … Cause Control Disease; traditionally linked with infectious bronchitis • Follow an effective vaccination program. Stress, e.g. frights and disturbances • To avoid frightening birds, minimize human activity in and around the shed. • Increase shed security to stop other birds and animals entering the shed. Crowding • Avoid overstocking. Incorrect or changes in the lighting programme • There should not be sudden, large increases in day length as pullets come into lay.
  57. 57. Pimples Description  Pimples are small lumps of calcified material on the egg shell.  Some can be broken off easily without damage to the shell while others may leave a small hole in the shell.
  58. 58. Cont. … Incidence  An incidence of about 1% of total production is common.
  59. 59. Cont. … Cause Control Thought to be caused by foreign material in the oviduct, which may be associated with: Ageing of bird • Keep flock age as low as economically possible. Poor nutrition • Prevent excess calcium intake in winter. Strain of bird • Be aware that some strains may produce eggs with a higher incidence of this fault.
  60. 60. Pinholes Description and  Pinholes, or very small holes in the egg shell.
  61. 61. Cont. … Incidence  usually affect less than 0.5% of total production.
  62. 62. Cont. … Cause Control May result from faulty laying down of the egg shell or from pimples being knocked off the shell. Both problems are thought to be associated with: Ageing of bird • Keep flock age as low as economically possible. Poor nutrition • Prevent excess calcium intake in winter. Strain of bird • Choose a strain which produces eggs with a lower incidence of this fault. Damage from toenail points or other small sharp projections • Make sure that cage floor slope is enough to allow eggs to roll away easily from the birds. • Remove sharp projections on cages and roll-out trays.
  63. 63. Mottled or Glassy Shells Description  When parts of the egg shell are translucent, it appears mottled or glassy. Such shells can also be thin and fragile.
  64. 64. Cont. … Description  When parts of the egg shell are translucent, it appears mottled or glassy. Such shells can also be thin and fragile.
  65. 65. Cont. … Cause Control Failure of the egg shell to dry out quickly after laying, which is made worse by: High humidity in the layer shed • The shed must be well ventilated. Crowding • Avoid overstocking. Disease • Make sure that layer stock come from parent stock vaccinated against infectious bursal disease.
  66. 66. Fungus or Mildew on Shells Description  Eggs affected by a fungus may have a green coating of powdery material or a black, beard-like growth on the shell.
  67. 67. Cont. … Incidence  This defect should not occur under good management.  Any incidence is unacceptable.
  68. 68. Cont. … Cause Control Poor hygiene during handling, storage and transport • Do not use soiled egg-handling equipment. • Regularly clean roll-out trays, collection belts and egg fillers. • Use correct egg-washing sanitisers and procedures. • Clean and disinfect coolrooms regularly. Warm storage conditions or excess coolroom storage of eggs with other produce • The storage temperature must be under 15 °C, and the humidity in the storage room under 80%. • Store only eggs in the cool room. Old eggs • Do not keep old eggs in handling and storage areas because they are more prone to fungal attack.
  69. 69. Cage Marks Shells Description  'Cage marks' is the term used to refer to dirty marks, dirty lines or translucent lines on the shell when eggs are collected.
  70. 70. Cont. … Incidence  In well-managed flocks, the incidence of this problem should be under 5%.
  71. 71. Cont. … Cause Control Dirty marks or lines are due to: Rusty or dirty wires in the cage fl oor or roll-out trays • Check wire floors, if they are rusty, either: • replace the floors. • regalvanise if possible, or • paint with a light-coloured paint. • Brush roll-out trays regularly to keep them clean. • Do not allow excessive build-up of manure under cages. • Remove manure caught in cage floors. • Do not allow ammonia to build up in sheds, as it causes corrosion of metal cages. • Make sure ventilation is adequate and that manure is kept dry.
  72. 72. Cont. … Cause Control Translucent lines result when the shell fails to dry out quickly after laying, which is made worse by: High humidity in the layer shed • The shed must be well ventilated. Crowding • Avoid overstocking.
  73. 73. Fly Marks Shells Description  Fly marks are caused by flies leaving droppings on the egg shell.
  74. 74. Cont. … Incidence  This defect should not occur under good management.  Any incidence is unacceptable.
  75. 75. Cont. … Cause Control Eggs exposed to large numbers of flies • Control flies on the farm by maintaining a high level of hygiene, by keeping manure dry and not allowing it to build up excessively and, when necessary, by using approved insecticides. • Use UV fly traps in egg-handling rooms. • Put fly screens on doors and windows in handling, packing and storage rooms. • Collect eggs frequently. • Store eggs in a cool room.

    Soyez le premier à commenter

    Identifiez-vous pour voir les commentaires

  • EsenGne

    Apr. 1, 2017
  • AliMohammed48

    May. 21, 2017
  • AnkitBhola2

    Oct. 29, 2017
  • AndargachewAssefa

    Nov. 20, 2017
  • SubhashSinghoya

    Apr. 18, 2018
  • monmon107

    Feb. 4, 2019
  • AbeerAbdelnaserAll

    Mar. 25, 2019
  • VRamasubbaReddy1

    Jun. 2, 2019
  • remofayez

    Sep. 13, 2019
  • SakibRahman27

    Oct. 12, 2019
  • tutorhigiene

    Oct. 23, 2019
  • mekidesmesfine

    Nov. 9, 2019
  • dr_podesta

    Nov. 12, 2019
  • MallamulaVishnu

    May. 18, 2020
  • NarayanasamyNadesaPillay

    May. 28, 2020
  • DrPrashantMAwarde

    Jun. 12, 2020
  • EmmanuelZDSonkarlay

    Aug. 22, 2020
  • ChouChooxx

    Oct. 16, 2020
  • engowi

    Dec. 23, 2020
  • ShubhamNandanwar2

    Apr. 10, 2021

"عسى ان يكون علما ينتفع به: Poultry eggshell egg shell quality cracked egg mishapen egg

Vues

Nombre de vues

4 854

Sur Slideshare

0

À partir des intégrations

0

Nombre d'intégrations

16

Actions

Téléchargements

467

Partages

0

Commentaires

0

Mentions J'aime

28

×