producing and selling eggs - college of agriculture ... · bag labels (order of inclusion, highest...

PRODUCING AND SELLING EGGS

Dr. Darrin KarcherAssistant ProfessorPurdue University

WHERE ARE WE GOING?• My background• Goals

• Why do you want to do this?• Facilities• Nutrition• Management considerations• Egg marketing

I AM.....

kccollegegameday.combleacherreport.comgreene.k12.ia.usresearch.fuseink.com

WHY DO I WANT TO GROW POULTRY?• Eggs• Dual Purpose• Hobby• Youth Projects

CHICK SOURCE

HOW DO I GET MY CHICKS?• Local farmer or supplier• Tractor Supply Company or equivalent• Mail order hatchery• Commercial supplier• Delivery method

• Postal service• Pick-up• Delivery

NATIONAL POULTRY IMPROVEMENT PLAN

HISTORICAL PERSPECTIVE• 1900’s

• Small flocks• Hobbyists• Limited to local business until 1918

• United States Postal Service

• 1935• Congress establishes program• Bacillary White Diarrhea (Pullorum)• States tried to control but failed

HISTORICAL PERSPECTIVE• 1944

• Turkeys added to the program• 1971

• Turkeys and chickens combined into single plan• Recent years

• Evolved into disease control program for egg transmitted and hatchery disseminated disease

WHAT IS THE NPIP PROGRAM?• Voluntary program (3 goals)

• Improve poultry breeding stocks• Control specific egg-transmitted diseases• Facilitate INTERSTATE movement of hatching

eggs and live poultry• Diseases

• Pullorum/Fowl typhoid• Avian Mycoplasmas• Salmonella enteritidis• Avian influenza

WHO ADMINISTRATES NPIP?• National level

• USDA• Michigan

• Michigan Allied Poultry Industries, Inc.• Michigan Department of Agriculture and Rural

Development• Michigan State University

DIFFERENT TYPES OF POULTRY• Laying hens

• Brown egg layers• White egg layers

• Dual purpose• Rhode Island Reds• Orpingtons• Rocks

• Ornamental• Silkies

• Heritage

EGG-LAYING BIRDS• Bred for egg production not meat• Average production is an egg/hen/day• Can lay 20-30 dozen eggs over 15-18

months• Assume 80% production from your flock (8

out of 10 hens always laying)• Eggs go from small to extra large and

jumbo• Consider force molting to extend lay

Breed selectionNational Poultry Improvement Program

QUESTIONS?

FACILITYCONSIDERATIONS

FACILITY DESIGN THOUGHTS• Space• Temperature control• Ventilation• Lighting• Predation• Clean

SPACE PER BIRD (EGG LAYERS)• Rule of thumb: 144 in2 (1 ft2)• Confinement (caged)

• 72 in2 minimum• Free-range

• 86 ft2 (500 hens/acre)

TEMPERATURE CONTROL• Keep house at least 45°F• Ideal is 70°F• Insulate ceiling and walls

VENTILATION• Tied closely to temperature

• Winter – minimal ventilation• Summer – maximum ventilation

• Goals of ventilating• Remove moisture • Remove excess heat• Remove gases from manure• Provide fresh air

VENTILATION

• Natural

• Powered

LIGHTING

LIGHTING• Minimum is 5 lux (0.5 foot candles)

• Put this in common terms:• 0.03 Watts per 1 ft2• So 10 ft2 takes a 0.3 watt incandescent bulb

• Another way to consider this:• Hold newspaper at arms length in front of you• Can you read it?

• Maximum of 20 lux (2 foot candles)

PREDATOR/WILD BIRD PROOF• Outdoor runs

• Netting for aerial predators• Bury perimeter fence ≥ 1 ft

• Rodent proof• Hardware cloth over windows, holes, etc.• Smaller holes and crevices sealed

CONSTRUCTION: EASY TO CLEAN• Concrete floors• Washable walls• Plastic or metal interior materials

• Feeders• Waterers• Nest boxes• Transport coops

• Dirt floor considerations

BROODING

SET-UP• Heat source and temperature• Feed• Water• Space

HEATING SOURCES AND TEMPERATURE• Gas brooders• Infrared bulbs (heat bulbs)

• White• Red

• Temperature• Where to measure?• ~95°F• Step down 5°F each week

BROODING PHOTOPERIOD

• Day 1 and/or 2• 24 hour is ok but not required

• Day 2 and/or 3 and beyond• 8 hour

FEEDER AND WATERER SPACE• Provide enough space for all birds• Adjust with age• Orientation

EXAMPLES

EXAMPLE – GAS BROODER

EXAMPLE – HEAT BULB

EXAMPLE – RADIANT HEATER

LISTEN AND WATCH YOUR CHICKS!

FacilitiesBrooding

QUESTIONS?

Biosecurity Principles

What is biosecurity?v “Bio” =“life” + ”security” =“protect”

v Measures taken to keep disease agents out of the flock

v Bacteria, viruses, and other bad things

Three components of biosecurity

v Isolation

v Keeping your flock from other animals

v Traffic control

v Who or what visits your flock

v Sanitation

v Keeping your equipment and buildings clean

Disease agent sources & Ways to protect your flock

Peoplev If you visit bird shows, swap meets, or neighbor’s sick

birds - shower and change clothes and shoes before going into your coop

v Never wear your street clothes or shoes into your coop

More peoplev Don’t allow other people into your coops unless you

provide them with coveralls and boots

v If you don’t have boots, supply a place to brush off adhering material from their shoes FOLLOWED by disinfecting outside of shoes in bleach water

Animalsv Don’t let dogs or cats in with your flock

v Keep rodents wild birds out

v Pick-up dead birds daily

Animal quarantinev Establish a quarantine location

v All new birds must stay there for at least 21 days - this includes birds returning from shows

v Take care of these birds after your other birds

v All a bird from your flock with the new ones and watch what happens - illness new vs. old

Buildingsv Clean out building and nests at least twice a year

v Dirt floor - turn over top 6 inches of soil in between flocks

v Allow two weeks downtime after the building and nests have been cleaned

v THE BEST TWO DISINFECTANTS ARE SUNSHINE AND TIME!!

Buildings and Pestsv Mow grass 10 feet around house to keep rodents away

v Remove piles of junk within 100 feet of buildings

v Screen openings with 1/2 inch screen to keep pests out

Equipmentv Wash and disinfect water and feed pans at least once a

week

v Remove all organic material with soap and hot water

v Use only clean and disinfected equipment for baby poultry

v Don’t share your equipment with other poultry people

Airv Some diseases an spread up to a mile on the air

v Keep this in mind when evaluating sites for new poultry buildings or flocks

Foodv Store feed in covered containers

v Store feed in cool, dry place away from sunlight

v Buy only enough to last 3 to 4 weeks

Waterv Chlorinate drinking water

v Make stock solution (1 tablespoon of household bleach per 1/2 gallon water)

v Add to animal drinking water at 2 tablespoons per gallon of water

v Replace stock solution at least once a week

How should I chore?v Go from youngest to oldest

v Go from healthy to sick

v Go from your flock to quarantine flock

v Example - young healthy to old healthy to young sick to old sick to quarantine birds

Choringv Have coveralls and boots for each building

v If not, use plastic disposable boots and change between each building OR use an iodine or phenol-based disinfectant as a foot bath

v Walk through foot bath before entering the bird area (Change when discolored or dirty)

A major NO, NO!!

Questions?

NUTRITION

NUTRITION IS…..

• a series of chemical, biochemical, and physiological processes that transform food elements into body tissues and activities

WHY SO IMPORTANT?

• Cost (~70%)• Need• Health• Different for each type

• Rapid growth of chick• Slower growth of chick

NOMENCLATURE

• Diet• Combination of feedstuffs used to supply nourishment to an

animal• Ration

• Amount of diet that an animal consumes in a 24-hr period• Natural ingredients

• Corn, soybean, wheat, barley• Natural processed

• Soybean meal, alfalfa meal, wheat middlings, corn gluten meal

• Synthetic• Crystalline amino acids, vitamins

NOMENCLATURE

• Mash• A blend of several feed

ingredients, ground to a small size but not to a powder

• Pellets• Small kernels of

compressed mash, causing birds to eat the whole blend, not pick and choose

• Crumbles• Pellets broken up into

smaller pieces

TYPES OF NUTRIENTS

• Essential – incapable of synthesizing in the body• Water• Protein• Carbohydrate• Fat• Vitamins• Minerals

• Nonessential – capable of synthesis within the body

NUTRITIONAL REQUIREMENTS -FACTORS

• Bird factors• Genetics (breed/strain)• Breeders (chicks), layers (eggs)• Age & sex

• Disease - may reduce nutrient absorbance• Type of housing (examples)

• Floor pens• Cages• Free-range

• Parasites (examples)• Beetles• Worms• Mice

NUTRITIONAL REQUIREMENTS -FACTORS

• Environmental Conditions• Comfort Zone (Thermoneutral Zone – TNZ) - Young birds need more heat• Low temperatures - Increased feed consumption (more energy, less

nutrients)• High temperatures - Reduced feed consumption (less energy, more

protein)• Type of grain available

• Corn & soybean meal• Wheat & Canola

• Diet factors• Mold toxins• Interacting nutrients

• Energy: protein• Calcium: phosphorus• Vitamin E + selenium• Lysine: arginine + other amino acids

• UV, chemical, or other destruction of nutrients

BAG LABELS(ORDER OF INCLUSION, HIGHEST TO LOWEST)

• INGREDIENTS• Ground Corn, Dehulled Soybean Meal, Rice Bran, Wheat Middlings,

Dried Bakery Product, Hydrolyzed Poultry Feathers, Whole Pressed Safflower Meal

• INGREDIENTS – Macronutrients (< 5%)• Calcium Carbonate, Dicalcium Phosphate, Monocalcium Phosphate,

Salt, L-Lysine, Vitamin A Supplement, Choline Chloride, Methionine Supplement

• INGREDIENTS – Micronutrients (0.3-0.5%)• Ferrous Sulfate, Manganous Oxide, Zinc Oxide, Calcium Pantothenate,

Niacin Supplement, Riboflavin Supplement, Vitamin B12 Supplement, Vitamin E Supplement, Copper Oxide, Menadione Sodium Bisulfite Complex, Vitamin D3 Supplement, Mineral Oil, Ehtylenediamine Dihydriodide, Folic Acid, Sodium Selenite.

GUARANTEED ANALYSIS

• Chick Starter (STK) w/Amprolium Medicated(As an aid in the prevention of coccidiosis)

• Active Drug Ingredients Amprolium .... 0.0125%• Guaranteed Analysis:

• Crude Protein Min 20.0%Lysine Min 1.0%Methionine Min 0.32%Crude Fat Min 2.5%Crude Fiber Max. 5.0%Ash Max 8.0%Added Minerals Max 4.0%Calcium Min 0.75% Max 1.25%Phosphorus Min 0.70%Salt Min 0.15% Max 0.5%Sodium Min 0.15% Max 0.30%

LAYER DIETS

• Fed different many feeds – Phase feeding • Chick starter • Chick grower• Developer• Pre-lay• Layer diets

• Pelleted, crumbled, mash• Diet changes based on:

• Consumption• Egg production• Body weight

LAYERS

Nutrient Starter Grower/Developer Layer

Energy (Kcal ME/kg) 2900 2900 2750-2900

Protein (%) 18 16-18 14-16

Amino acids Decrease with age

Calcium (%) 1 1 4-4.5

FREE CHOICE OPTIONS

Oyster shell (calcium)

GritVariety of broken, mixed grains

QUESTIONS?

Management Considerations

* Keep off floor* Keep out insects, rodent, and other animals* Keep feed in cool (if possible) and dry location* Never feed moldy feed* Fresh feed each morning (summer)* Shaded area for feed and water, if outside

* There is little nutrition in fresh grass, good source of pigmentation (yolk color)

* Monitor feed consumption

Feed Management

Time Egg layers Notes

Day 1-2 24hr

Day 3 8hr

Week 18 10 hrIncrease day length

slowly until youachieve 16 hrs

Week 30 16 hr

Week 85 8 hr Forced molting

Week 95 16 hr

Lighting

* Clean 1 or 2 times a year* Storage - keep it dry to cut odor & stop fly breeding* Stir litter & add new litter to dry* How much manure is produced?* 0.3 lbs/chicken/day (Mature)* 1.2 lbs/turkey/day (Mature)

* Nutrient profile

Manure Management

* Poultry very social* Hierarchy established from top to bottom* Resources allocated according to hierarchy* Need to ensure sufficient space for feed, water, nest

boxes, etc. to account for this

Social Structure

* Overcrowding * Insufficient feeder, waterer or nesting space* Flock nervousness or overexcitement (may be breed

related)* Dietary absences or deficiencies* Incorrect lighting (usually too much light)* Lame birds left in the flock* Stresses due to moving birds or making other necessary

management changes

Behavior issues - Cannibalism

* Prolapse of another egg laying female * Females laying on the floor rather than in a nest or cage * Timid birds in the flock that are not getting enough feed or

water* Keeping different ages or colors together * Extremely high environmental temperatures* Abrasions or tears that may be the result of an accident or

mating* Diseases, especially if the nervous system is affected * Pure meanness on the part of the birds

Behavior issues - Cannibalism

* "Goggles" or "bits" affixed to the bird's beak, or "tin pants" on the vent

* Applying "anti-pick" compounds (commercial "anti-pick", pine tar or axle grease) to wounded areas

* Removal of birds doing the picking * Continue dim light to minimize activity* Keep birds busier

* Locate semi-solid milk or whey blocks around the house for birds to eat* hanging green leafy vegetables in the pen for the birds to pick * spread grass clippings in the pen daily * turn the birds outside* feed small grains in deep litter

Cannibalism – Corrective Actions

Cannibalism – Corrective Actions

* Feed changes* Picking depressants* Eliminate areas where

bright sunlight strikes the floor

* Beak trimming

* Overcrowding* Light too bright* Inadequate nests* Insufficient nest litter* Dispose of cracked or broken eggs on floor* Nutritional deficiency

Egg Eating Factors

* Gather eggs more frequently* Increase nesting area* Darken nests* Beak trim birds * Mixing 2 tsp ground pepper into a an egg and

distributing on floor (Will it Work??)

Egg Eating – SOLUTIONS???

* Hormonal changes occur in hen* Cessation of eggs * Remove eggs daily to eliminate chances* Remove hen from nest area for several days to break

the broodiness

Broodiness

* External parasites * Irritate the birds * Prevent proper growth and development* Reduced egg production* Check birds weekly * Inspect skin around the vent and head* Dust the birds with Malathion or Sevin

Ectoparasites (Mites & Lice)

Egg Handling, Washing, & Storage

Darrin M. Karcher, Ph.D.March 3, 2017

Egg Handling

Egg Handling

ò Most eggs are laid by 10 am

ò Collect eggs in a timely manner (1 to 2 times/day) to prevent

ò In warm temperatures eggs need to be collected more frequently

ò Prevent eggs from being broken in order to minimize a hen learning to eat an egg and developing egg eating habits.

ò Keep rats, predators and snakes away from the hen house. They often will eat eggs and contaminate the nesting boxes and other eggs

ò Eggs laid other than in the nests are a greater risk

ò Floor Eggs

Coop and Nest Management

ò Keep the laying flock in a fenced area so they cannot hide their eggs or nest anywhere they choose.

ò If hens are allowed to nest wherever they choose, you will not know how old eggs are or with what they have been in contact

ò Clean Environment

ò Keep the layer in a environment clean and dry

ò Muddy outside run, dirty or damp litter and dirty nesting material will result in dirty eggs

ò Make sure the outside run area has good drainage and is not over grazed

Coop and Nest Management

ò Nest Spac:

ò Supply a minimum of one nesting box for every 5-7 hens in the flock

ò For larger flocks provide one nest for every 4 to 5 hens in the flock

ò Limit egg breakage from normal traffic and daily egg laying.

ò Make sure nests have a deep clean layer of litter to prevent breakage and help absorb waste or broken egg material.

Candling, Weighing, Packaging

ò Candle Eggs to remove defects

ò Crack

ò Blood

ò Dirt

ò Weigh eggs and sort by size

ò Place in carton

ò Refrigerate

ò 45°F

Exterior (Shell) quality factors (fixed)

1. Shape and texture

2. Soundness

3. Cleanliness

Egg Washing

Function of Egg Washing

ò Eliminate physical egg dirts and defects from entering the shell egg market

ò Provide an egg which is visually pleasing to the consumer

ò Clean the shell to minimize the risk of microbial contamination

Cleaning– major concepts

Egg Grading and Washer(Pre-processing)

ò Processing Plant Sanitation is vital

ò GMPs

ò SSOPs

ò If equipment is not cleaned properly egg washing and sanitation effects are nullified

ò Before processing and grading begins inspect the machine for cleanliness

ò Wash tank

ò Brushes

ò Scales

ò Packer head belts

Washing

ò To assure a clean appearance, washing is the most effective and simplest method for removing dirt and stains from the shell.

ò What effects washing

ò Wash water temperature

ò Water characteristic

ò Condition and action of washer brushes

ò pH

ò Hardness/Softness

ò Detergent and defoamer

Washing

ò Egg wash water temperature must be maintained at 90°F and/or should be at least 20° F warmer than the warmest eggs.

ò Eggs should not be immersed into the washing solution

ò Maintaining proper spray pressures and brush condition maximizes the cleaning action.

ò Wash water should be clean and changed frequently

ò 4 Hours

ò 5 Hrs with approval

Egg Washing Detergents

ò According to the Food and Drug Administration (FDA) the ingredients in the material used to clean eggs must be Generally Recognized as Safe (GRAS). The ingredients must also be a substance that is regulated as a food additive (USDA FSIS, 2008). Ingredients in compliance with FDA guidelines can be found in the Code of Federal Regulations.

ò Detergents help remove dirt and kill microbes during wet cleaning. Detergents generally raise water pH to 11 and the alkaline environment helps kill microbes, including salmonella (Zeidler, 2002).

ò There are many detergents or egg soaps on the market. For example, Egg Wash Powder is an alkaline chlorinated foam controlled powder available through Incredible Egg Washer Co., Nasco and other suppliers.

Washing

ò pH basic (alkaline)

ò pH 10-11

ò Alkaline detergents.

ò Potassium hydroxide

ò Quaterinary ammonium compounds

ò Sodium carbonate

ò Sodium hydroxide

ò During washing, a substantial amount of the cuticle may be damaged allowing carbon dioxide and moisture to be lost at a more rapid rate which provides easier points of entry for microbes.

More cuticle damage

Organic Egg Washing Detergents NOP

ò In certified organic processing under the National Organic Program, §205.605 of the National List lists non-agricultural (nonorganic) substances that may be used in processed products labeled as organic or made with organic ingredients.

ò The list includes natural materials such as citric and lactic acids and synthetic materials including chlorine, hydrogen peroxide, ozone potassium hydroxide, and peracetic acid. The Organic Materials Review Institute (OMRI) lists brand name products that are allowed under this National List.

ò The name brand list includes AFCO 5242 Egg Wash Org, whose main ingredient is potassium hydroxide. Keep in mind not all possible options are listed because there is a cost for OMRI listing.

Egg Washing Detergents

ò Be conscious of where your wash water goes, as ongoing and excessive use of detergent could be harmful to your septic system.

ò If you dispose of wash water on farm, a gentler soap or other material should be used. IPS-CareFree Enzymes, Inc. has an egg wash product called Egg Washer Pro that breaks down contaminants with a blend of enzymes that make up the wash. Some small producers use a solution of distilled white vinegar diluted in half with water to wipe their eggs. Vinegar can aid in removing stains from the shell and is known to have antibacterial properties due to its acidity (Entani et al., 1998).

Post Wash Rinse

ò Rinse the eggs with clean water containing an approved sanitizer that is slightly warmer than the wash water (at least 3°).

ò Be sure the water

Iron content is

less than 2 ppm but

if present it can be

removed from the

water prior to use.

Rinsing Eggs

ò After washing, eggs are sanitised to reduce microbial load

ò Chlorine-based sanitisers should be from 50 to 200 ppm (Zeidler, 2002)

ò However, using less than 100 ppm chlorine may help protect the cuticle (Hutchison et al., 2003).

ò One tablespoon of household chlorine bleach, usually 5.25 per cent sodium hypochlorite, per gallon of water will result in a solution of 200 ppm chlorine (McGlynn, 2009)

ò Free chlorine level must be frequently checked because chlorine is inactivated by organic material such as dirt. Chlorine test strips are

Organic Rinsing Eggs

ò After washing, eggs are sanitized to reduce microbial load

ò Organic requirements permit a final rinse with a chlorine level less than 4ppm, the limit under the Safe Drinking Water Act

ò See the OMRI product list for approved sanitizers and check with the individual company to ensure the product can be used on shell eggs.

ò Interestingly, in a test comparing the effectiveness of sanitizers including chlorine, electrolyzed water and peracetic acid, none of the sanitizers were more effective than rinsing with water (Musgrove et al., 2008).

Candling, Weighing, Packaging

ò Candle Eggs to remove defects

ò Crack

ò Blood

ò Dirt

ò Weigh eggs and sort by size

ò Place in carton

ò Refrigerate

ò 45°F

Microbial Quality

ò Shell

ò Main function of the shell is to contain all of the parts of the egg.

ò Physical barriers

ò Cuticle

ò Shell

ò membranes

Bacterial Isolates from Shell Eggs

16%

10%

4%

4%

13%4%

13%

36% E. coliP. vulgarisPseudomonasEnterobacterUnidentified G-StaphylococcusStreptococcusUnidentified G+

Lucore, 1994

Function of Shell Cuticle

ò May be antimicrobial for about 96 hours

ò Dries out, cracks

ò Damaged during washing process

ò Cooling the egg as quickly as practical after packing is very important

Microbial Quality

ò Shell is covered by the cuticle - a physical barrier to bacteria.

ò Cuticle may be antimicrobial for about 96 hours

ò Cuticle may dry out and crack - usually damaged during the washing process.

Microbial Quality

ò Egg has chemical barriers to prevent movement of bacteria into the egg.

ò Bacteria penetrating the membranes must survive chemical barriers presented by the various proteins of the egg white.

ò Conalbumin

ò Lysozyme

ò Ovomucin

ò Avidin

ò Ovomucoid

Egg Refrigeration

Bacterial Isolates from Shell Eggs

16%

10%

4%

4%

13%4%

13%

36% E. coliP. vulgarisPseudomonasEnterobacterUnidentified G-StaphylococcusStreptococcusUnidentified G+

Lucore, 1994

Microbial Quality

ò Shell is covered by the cuticle - a physical barrier to bacteria.

ò Cuticle may be antimicrobial for about 96 hours

ò Cuticle may dry out and crack - usually damaged during the washing process.

Shell Cuticle

Lucore, 1994

Microbial Quality

ò Main function of the shell is to contain all of the parts of the egg.

ò Creates limited physical barrier to movement of bacteria into the egg.

Microbial Quality

ò An effective barrier to bacterial penetration are the two shell membranes.

ò Function like

a micron filter.

Lucore, 1994

Microbial Quality

ò Bacteria penetrating the membranes must survive chemical barriers presented by the various proteins of the egg white.

ò Conalbumin

ò Lysozyme

ò Ovomucin

ò Avidin

ò Ovomucoid

Microbial Quality

ò Final barrier is the vitelline membrane that encloses the yolk.

Side

Top

Bellairs et al., 1963

Factors influencing decline of quality

ò Also related to the strength and condition of the shell and shell membranes.

ò The rate of change in quality of the albumen and yolk is a function of temperature, humidity and loss of carbon dioxide and moisture.


ò Egg quality is highly correlated with the physical condition of the albumen and yolk


ò Temperature

ò Near the body temperature of the hen (105°to 107° F.) when laid.

ò Today’s regulatory requirements call for the holding temperature of eggs to be at or below 45°F.


ò Temperature conditions can slow moisture and carbon dioxide loss, keep the air cell small, maintain thick albumen, keep the yolk round and firm, and slow microbial growth.

ò Production House

ò Processing Temperatures

ò Packaging

ò Storage temperatures

ò Delivery temperatures

Internal Egg Temperatures from Oviposition through 5 days post processing (°F)

20

40

60

80

100

120Summer EggWinter EggWinter StorageWinter DeliverySummer StorageSummer Delivery

Oviposition

Prod

uctio

n Ho

use

24 h

rEggs Placed in Cooler

Time to reach Ambient 120 to 140 hr

Point at which most eggs are shipped out

Patterson et al., 2003; Koelkebeck et al., 2003); Anderson et al., 2004


ò Humidity

ò Humidity in the storage environment is of importance for maintaining egg weight.

ò Low relative humidity (below 60%) can cause severe weight loss due to evaporation, with a corresponding increase of air cell size.

ò High relative humidity (above 80%) can cause an increase in microbial growth.


ò As the egg ages, water migrates from the albumen to the yolk.

ò Increases the size and weight of the yolk - stretches the vitelline membrane.

ò Causes yolks to flatten and break easily.

ò The rate of this deterioration is increased by high storage temperatures.


ò There is also a movement of some lipid material from the yolk to the albumen.

ò This movement of lipid material into the albumen will effect its functional properties after a time.

ò The yolk material also inactivates antimicrobial components of the albumen


ò Carbon Dioxide and Moisture Loss

ò Carbon dioxide movement out of the shell causes loss of albumen quality - a thinning effect.

ò CO2 will move out of the shell until an equilibrium exists.


ò Keeping shell eggs in closed containers helps keep the CO2 in the immediate environment higher and slows the rate of loss from the egg.

ò The rate of loss is highest within the first few hours (6 to 8) after ovulation.


ò Egg shell pores allow moisture and carbon dioxide to escape from the egg.

ò Results in a decrease in egg weight, increase in the albumen pH, and an increase in air cell size all of which are not desirable in a market egg.


ò The pH of the albumen increases as carbon dioxide is lost.

ò When laid, the albumen pH is 7.6-7.9.

ò As carbon dioxide is lost it begins to rise to a high near 9.7.


ò When the albumen becomes more alkaline, the gel structure begins to break down and the albumen becomes thin.

ò Eventually, the yolk membrane is affected by the alkaline pH and becomes weak.


ò This allows the yolk to flatten and the membrane weakens.

ò Such yolks pass closer to the shell during candling which causes them to cast a darker shadow on the shell, resulting in the egg being downgraded.

Egg Safety Rule

ò Refrigerate shell eggs within 36 hrs of being laid

ò Refrigeration temperature must be maintained at 45°F or below

ò Prior to processing a 36 hr tempering period is allowed to allow eggs to warm prior to processing in order to minimize thermal checking

FDA Information

ò http://www.fda.gov/Food/FoodSafety/Product-SpecificInformation/EggSafety/EggSafetyActionPlan/default.htm

ò http://www.fda.gov/Food/GuidanceComplianceRegulatoryInformation/ShellEggProducerRegistration/default.htm

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