Lee Cartwright Incubating and Hatching Eggs

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    B-60925-00

    Incubat ingand

    Hat ch ing Eggs

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    Incubat ing and Hat ching EggsA . L e e C a r t w r ig h t *

    Eggs of exotic birds and commonchickens require a standard measureof care in storage and incubation toensure a successful hatch. Environmentalconditions, handling, sanitation and recordkeeping can impact the success of incubatingand hatching eggs.

    Fer t i l e Egg Qua l i t yFrom the smallest canary eggs to the

    largest ostrich eggs, high quality fertile eggsshould always be considered rare and fragile.To successfully hatch eggs, begin with fresh,clean, fertile eggs.

    Eggs can be produced on site or pur-

    chased from many sources. Commercialhatcheries will ensure good fertility, but oftenwill not ship small quantities of eggs.

    Eggs easily transmit contagious diseasesbetween flocks. Therefore, to ensureprotection from such diseases, purchaseeggs from only National Poultry Improve-ment Plan (NPIP) or equivalent surveyedfacilities. Every egg producer should beNPIP tested; further information can beobtained from Texas A&M University NPIPat (979) 845-4186.

    If eggs are purchased by mail order, it isimportant to ensure that the eggs receiveproper care in transit. Extremes of tempera-ture and poor handling can destroy prospectsfor a good hatch.

    If fertile eggs are produced on site at thebusiness location, the breeding stock must bemaintained and supported for maximumhealth and fertility. Basic egg production isseverely affected by day length and lightingcontrol. Egg quality and embryo livability areaffected by hen and sire age, health, nutri-tion, cock/hen ratio, breeder genetics, and

    other factors that can stress birds such as theweather. Keeping more than four females permale can reduce fertility in some settings.Inbreeding, the mating of closely relatedmales and females, might decrease fertility ofeggs and increase embryo mortality. Hatch-ability of eggs is severely harmed by inbreed-ing, age and poor health.

    * Extension Poultry Specialist, The Texas A&M Univer-

    sity System.

    Most eggs are laid by mid-morning. Eggsshould be collected several times a day toreduce the amount of time eggs remain in the

    nest. This practice decreases the number ofcracked and soiled eggs and also preventspremature incubation. Embryos begin toprematurely develop at temperatures above72 degrees F. Starting and stopping embryodevelopment by repeatedly changing tem-peratures increases embryo death. Frequentcollection and proper storage delays embryodevelopment until egg incubation can begin.

    St or ing Fer t i l e EggsFertile eggs are alive. Each egg contains a

    living cell mass that develops into an em-bryo, and finally into a chick. Each incidenceof improper handling reduces the probabilityof a successful hatch. Fertile eggs usually aregathered over a period of time before anadequate number of eggs can accumulate forincubation, or until the incubator is availablefor a new set of eggs. These normal situationsrequire that, before incubation, eggs must bestored properly to ensure hatchability.

    Cleaning and cullingCracked, poorlyshaped, soiled and unusually large or smalleggs should not be incubated. These eggs

    rarely hatch and they increase the probabilityof introducing infection into the incubator.

    Eggs should not be washed. Washing orwiping with a damp cloth removes a protec-tive layer that coats the egg. Soiled eggsshould be cleaned by gently buffing thesoiled area with fine sandpaper. Washingeggs transfers disease infection agents fromthe surface to the inside of the eggs.

    If an egg is washed, it should be washedbriefly in 110-degree F water that contains acommercial egg sanitizer. Washing an egg in

    water that is cooler than the egg itself causesegg contents to contract. Contraction of eggcontents draws water into the egg throughpores in the shell. This water carries infectingmicroorganisms into the egg.

    General careAfter clean and undam-aged eggs have been selected for incubation,use great care to prevent damage or contami-nation of the eggshells. This includes usingfrequent hand washing as a barrier to micro-bial contamination.

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    Storage timeIdeally, eggs should be setin the incubator as soon after gathering aspossible to maintain egg quality. If eggs areto be stored before incubation, the besthatchability occurs when eggs are stored forless than 7 days from the time they were laid.However, some species are more sensitive tostorage than other species. Hatchability

    decreases rapidly in eggs held in storage formore than 10 days. Storing eggs longer than2 weeks also can extend the normal incuba-tion time as much as 1 day.

    Temperature and humidity duringstorageFertile eggs should be stored at adry bulb, normal temperature between 55degrees F and 65 degrees F, or 13 degrees Cand 18 degrees C. Embryos will begin todevelop abnormally, weaken and die if thetemperature is too high. A low temperaturealso causes high embryo mortality. Storage

    temperature should never exceed 72 degreesF (22 degrees C) and never go below 46degrees F (8 degrees C). Egg storage at roomtemperature or at normal refrigerator tem-peratures (32 degrees F to 40 degrees F) is notacceptable because hatchability decreases.

    A refrigerator can be used to store eggs ifthe temperature is properly adjusted to therecommended temperatures. Eggs should bestored in a refrigerator dedicated to eggstorage because these temperatures are notlow enough to safely store food. Storagetemperature should be reduced to 50 degrees

    F or 55 degrees F if eggs must be stored morethan 2 weeks.

    Holding eggs for more than 10 daysreduces hatchability. However, chukar andturkey eggs are an exception. Chukar eggshave been stored 3 weeks to 4 weeks withoutappreciable loss in hatchability.

    A good storage area also requires stablehumidity. Two methods, wet bulb tempera-ture and relative humidity, are measures ofhumidity. These two methods should not beconfused; whenever humidity measures are

    discussed, know which method is referenced.Relative humidity is the water vapor in

    the air expressed as a percentage of thegreatest amount of water vapor possible atthat temperature. The amounts of watervapor that air can contain are different atdifferent temperatures. To measure relativehumidity, expensive equipment or a compli-cated procedure is required. However, thewet bulb temperature is easily measured andis the method usually used to measure

    humidity in an incubator. Relative humidityis expressed as a percentage while wet bulbtemperature is expressed as degrees.

    A wet bulb thermometer can be purchasedor made from a common dry thermometer.Knowing how to make a wet bulb thermom-eter helps to understand how it works. Athermometer, a shoelace (approximately a 6-inch long piece) and a short piece of dentalfloss are needed. First, stick the bulb end ofthe thermometer about 1 inch into the hollowof the shoelace. Next, tie a piece of dentalfloss around both the shoelace and thermom-eter directly above the bulb. This is to keepthe shoelace from sliding off. Place theopposite end of the shoelace directly in a panof water. If the water is the same temperatureas the air temperature, the reading on thethermometer is the wet bulb temperature.The temperature reading of the wet bulb will

    be less than a dry thermometer becauseevaporation of water cools the thermometer.

    However, the reading also will be influ-enced by the relative humidity of the air. Thewet bulb reading is used as an index ofrelative humidity but is not numericallyequal to the relative humidity value. The wetbulb temperature will change at different drybulb temperatures even as the relativehumidity remains constant. So, the appropri-ate wet bulb temperature that is to be main-tained must be known for each dry bulbtemperature that occurs during storage.

    Relative humidity in the storage roomshould be approximately 70 percent to 80percent (wet bulb temperature of 50 degreesF to 60 degrees F). Condensation forms oneggshells exposed to excessive humidity.Condensation on the eggshell can clog poresand, like washing eggs, provides a vehicle forcontamination. Suffocation or contaminationof the embryo can result. Excessive amountsof water evaporate from the egg if humidityis too low, which also causes embryo death.To increase the humidity, a pan of water can

    be placed in the storage room. If the incuba-tor temperature is correct, the only factorgoverning humidity is the surface area ofwater inside the incubator or storage unit.Avoid drafts during storage that can dry eggseven when humidity levels are withinappropriate levels.

    Hatchability is best maintained by storingeggs with the small end down in sealed,airtight plastic bags. The bags help keep theeggs clean and prevent moisture loss.

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    Positioning and turning eggs duringstorageEggs that will be stored for lessthan 10 days before incubation should beplaced on egg flats or in egg cartons withthe large end up. Eggs do not need to beturned from side to side during storage ifthey are incubated within the week theeggs are laid. If the eggs are not sealed in a

    plastic bag, cover them with a loose fittingmaterial to prevent debris or dust fromsoiling the eggs.

    Eggs stored for more than 10 days shouldbe tilted from side to side over a 90-degreeangle once or twice a day to assure optimalhatching success rates. To turn eggs duringthe holding period, place a 6-inch blockunder one end of the carton (or flat) holdingthe eggs to produce a 45-degree angle againstthe floor. The next day, remove the block andplace it under the opposite end of the carton.

    Turning eggs prevents some hatchability lossthat can occur during long-term storage.

    Incubat ionWhen an adequate number of eggs are

    collected, move eggs from storage to incuba-tion.

    IncubatorsIncubators of several typesand capacities with adapters for eggs fromdifferent species are available. Basically, anincubator is a box that holds and rotates eggswhile maintaining appropriate temperature,

    humidity and oxygen levels. A well-designedincubator should maintain temperaturewithin 1/4 degree F and humidity within 1degree F wet bulb temperature.

    Several features are standard in popular orlarger incubator models. Automatic turnersthat turn eggs at least once every 2 hours to 4hours are recommended. Humidifiers are ofseveral types. Some are actuated by wet bulbsystems while others are designed to main-tain humidity by a simple water reservoirsurface area system. Either of these systemscan be used effectively. Temperature can becontrolled by the older wafer system or bynewer microprocessor systems. Whatever thesystem chosen, an incubator with a backupcontroller set at less than 102 degrees F cansave the hatch if the primary temperaturecontroller ever malfunctions. Remember thattemperature, humidity, ventilation andturning are the important factors duringincubation.

    Consider the differences between forced-draft and still air incubators before choosing asystem to use. Forced-draft incubators main-tain more consistent temperature and humid-ity levels throughout the incubator, andrecover temperature and humidity to regu-lated levels faster when doors are openedduring the incubation period. In still airincubators, wet bulb readings are misleading

    and a water reservoir with a large surfacearea is needed. Temperatures in still air incu-bators must be monitored at the level of theeggs since temperature can vary considerablybetween locations within a still air incubator.Forced-draft incubators are preferred.

    The temperature and humidity of the roomhousing the incubator should be controlledand stable. Place the incubator in a stableenvironment, free of drafts and away fromdirect sunlight.

    Locate the incubator and hatcher away

    from growing facilities. The equipment andnewly hatched chicks can be contaminated byolder birds, and the dust that accompaniesgrowing birds. Keep foot traffic to a mini-mum; personnel should limit trips betweenthe growing area and the incubation area asmuch as possible. Do this by attending to theincubator and hatchlings before maintainingother areas.

    Chicks can be hatched in the same unit inwhich they were incubated. However, hatch-ing creates large amounts of dust and down.Hatching in a separate unit prevents contami-

    nating and soiling the incubator. Temperatureand humidity also can be managed moreeffectively if separate units are used forincubation and hatching. It is best to keephatchers in a separate room from the incuba-tor. The incubator and the hatchers should beconstructed and coated with material that iseasily sanitized. The incubation and hatcherrooms should also be constructed or coatedwith impermeable material that can be easilywashed and sanitized.

    Egg St orage Remin dersC Store less than 10 days.

    C M aintain tem perature betw een 55 d egrees to 6 5 degrees F.

    C Keep relat ive hum idi ty at 75 percent (50 to 60 d egrees F w et

    bulb temperature).

    C Turn egg s stored m ore than a w eek.

    C Handle the egg s wi th care!

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    Two days before incubationPrepareand adjust the incubator 2 days or 3 daysbefore setting the eggs. Ensure that theincubator is clean and sanitized. Make properadjustments to the temperature and humidityat this time. Adjustments made while eggsare set can either lengthen or shorten thetime of hatch, or kill or damage the embryos.

    If the incubator has an automatic turner,make sure the turner functions properly. Thetemperature in the room where the incubatoris located should also be controlled duringthis time. Do not set the eggs until tempera-ture and humidity are correct and stable.

    Cleaning and fumigationMicrobialinfection in an incubator can significantlyreduce hatchability of eggs. Cleaning proce-dures and disinfecting equipment should bepart of standard operating procedures.Incubators, hatchers and the racks should be

    disinfected with quaternary ammonia orcommercial disinfectant after each hatch.

    Some larger businesses fumigate incuba-tors before setting eggs. Occasionally theincubators are fumigated briefly with lowerconcentrations of the fumigant while eggs arein the incubator. Do not fumigate eggs afterthe first day of incubation. Embryos aresensitive to fumigation between 2 days and 5days of incubation. When eggs are fumigatedat set, exposure of the eggs should be limited.Only trained individuals should use thesetechniques.

    The day eggs are setRemove eggs fromstorage and allow them to warm to roomtemperature for 4 hours to 8 hours beforesetting in the incubator. Cold eggs placedinto a warm, humid incubator will becomecovered in condensation that will increasethe possibility of egg contamination. Ensurethat proper records are maintained so thateggs are turned a minimum of three to fivetimes in a 24-hour period. Failure to turneggs adequately results in embryo death. Useof an automatic turner considerably simpli-

    fies the work and decreases human errorduring the incubation process.

    Once eggs are in the incubator, do notadjust the temperature or humidity for a fewhours unless the temperature exceeds 102degrees F. After 4 hours, make proper adjust-ments. The final temperature should varyonly 1/2 degree above or below 99.5 degrees F.The temperature of incubators withoutcirculating fans fluctuates more than incuba-tors with circulating fans. If the temperature

    does not exceed 102 degrees F, the hatchshould not be harmed.

    The small end of the egg should be lowerthan the large end of the egg when set in theincubator. An embryo orients during incuba-tion so that the head develops toward thelarge end of the egg where the air cell islocated. A chicks head can orient away fromthe air cell of the egg if the small end ishigher than the large end during incubation.An embryo oriented in the wrong directionwill not hatch.

    Set stageThe set stage refers to thedays of incubation prior to the final 2 days or3 days before a hatch. Different species havedifferent incubation periods (Table 1).Incubating different species at the same timein the same incubator is not recommended,especially if the incubator is also used as ahatcher.

    Birds in the wild frequently turn their eggsin the nest. Similarly, turning eggs duringincubation prevents embryo death andunhealthy hatches. Eggs must be turned atleast five times within a 24-hour period.Turning more frequently is better; once perhour is best. This turning schedule must bemaintained even through weekends. Anautomatic turner is recommended. If theincubator is equipped with an automaticturner, eggs will be turned at least every fewhours.

    Temperature, humidity and ventilation ofincubator (set stage)Temperature in theincubator should be 99.5 degrees F to 100degrees F (37.5 degrees C). If the temperaturedeviates more than 1/2 degree from 100degrees F, a poor hatch is likely. Temperatureshould be checked at least twice a day.

    Relative humidity should be set at 86degrees F to 88 degrees F (30 degrees C) wetbulb temperature. Humidity should notfluctuate more than 1 wet bulb degree. If theincubator uses a passive humidity controlsystem, water should be added daily to the

    water pan or trough to ensure correct humid-ity levels.

    If the humidity in the incubator is too lowor too high, the hatch will fail. When humid-ity is too low during incubation, the air cellwill be too large at the time of hatch. Thecontents of the egg will be too thick andsticky for the chick to turn. The membraneswill be too tough to break. The navel will notclose properly.

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    Table 1. Tot al incubatio n tim e to hatch, t im e for transfer to hatcher, and dr y and w et bulbtem peratures for com mo n birds.

    Com m on Nam e Incubat ion Cond it ions Hat cher Cond it ions

    Per iod Dr y Bulb W et Bulb Transfer Dr y Bulb W et Bulb

    (days) ( F) ( F) at day ( F) ( F)

    Canary 13 -14 100 .5 86 -88 11 99 90-94

    Chicken 21 99 .5 86 18 98 .5 90 -94

    Cockat iel 18 -20 99 .5 86 -88 15-18 99 90-94

    Cockatoo (various) 22 -30 99 .5 86-88 20-27 99 90-94

    Conure (Sun) 28 99 .5 86 -88 25 99 90-94

    Conure (various) 21 -30 99 .5 86-88 18-27 99 90-94

    Dove 14 99 .5 86 12 98 .5 90 -94

    Duck (com m on) 28 99 .5 86 -88 25 98 .5 90 -94

    M uscovy Duck 35-37 99 .5 86-88 31-33 98 .5 90 -94

    Finch (Zebra) 14 99 .5 86 -88 12 99 90-94

    Do m est ic Goose 30 99 .5 88 27 98 .5 90 -94

    Geese (var ious) 22 -30 99 .5 88 20-27 98 .5 90 -94Grouse 24-25 99 .5 84 -86 22 99 90-94

    Gu inea 28 99 .5 84 -86 25 98 .5 90 -94

    Loveb ird (various) 22 -25 99 .5 86-88 20-22 99 90-94

    M acaw (various) 26 -28 99 .5 86-88 23-25 99 90-94

    M ynah 14 100 .5 86 -88 12 99 90-94

    Parakeet (various) 18 -26 99 .5 86-88 15-23 99 90-94

    Budgerigar 18 99 .5 86 -88 15 99 90-94

    Parro t (various) 18 -28 99 .5 86-88 15-25 99 90-94

    Parro t (A f rican Grey) 28 99 .5 86-88 25 99 90-94

    Chukar Par t ridge 23-24 99 .5 88 20 99 90-94Peafow l 28 -29 99 .5 86-88 25-26 98 .5 90 -94

    Pt arm igan 21-23 99 .5 86-88 18-20 99 90-94

    Raven 20-21 99 .5 86 -88 17-18 99 90-94

    Ring -neck Pheasant 24 -25 99 .5 86-88 21 99 92-95

    Pheasan t (various) 22 -28 99 .5 86-88 20-25 99 92-95

    Pigeon 17-19 100 .5 88 14 99 92-95

    Bobw hite Quail 23 99 .5 84 -86 21 99 90-94

    Japanese Quail 17 -18 99 .5 86-88 15 99 90-94

    Sw an (various) 33 -37 99 .5 86-88 30-33 99 90-94

    Turkey 28 99 .5 84 -86 25 98 .5 90 -94Em u 49-50 97 .5 70-75 47 97 .5 90

    Ost rich 42 97 .5 70-75 39 97 .5 90

    Rhea 36-42 97 .5 80 97 .5 90

    1 This period is the entire incubation t ime unti l hatch that includes 3 days in the hatcher. Venti lation should be increased halfway through the incubat ion per iod.

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    If the humidity in the incubator is too highduring incubation, too little water willevaporate from the egg. The air cell will betoo small for the chick to reach during thehatching process. The chick will either drownor the chick will be too swollen with water toturn itself within the egg. The yolk sac willalso be too large for the navel to completely

    close. These problems will cause the hatch tofail.

    The air cell of the egg should becomelarger as incubation progresses. Chicken eggswill lose 12 percent to 14 percent of their totalweight by evaporation during incubation.The growth of this air cell is a balancebetween temperature and humidity duringthe incubation. Racks of eggs can be weighedduring incubation to detect problems withhumidity and evaporative loss before a hatchis destroyed.

    The chick embryo uses oxygen andproduces carbon dioxide. This gas exchangeis insignificant during the early period ofincubation or when a small number of eggsare incubated. However, recommendations ofthe incubator manufacturer should befollowed to assure that adequate oxygen isavailable to the developing chicks. Near theend of the incubation period, the eggs arenearly filled with the embryo. An incubatorfilled with eggs contains a large animal massthat requires large amounts of oxygen.Adequate ventilation is needed during the

    end of the incubation period. Particularattention should be focused on air ventsettings, and wet and dry bulb temperaturesduring the last third of incubation.

    Record keepingKeep a daily record ofthe incubator environment (Appendix A).This sample record is designed for use witheggs that hatch after 21 days of incubation.Record keeping can be used to detect mal-functions before a disaster develops. Also,records of fertility and embryo deaths alertthe hatchery manager to production, storage,

    or incubator problems so that adjustmentscan be corrected before major losses occur.

    Proper records call attention to deviationsthat could destroy a producers profits. A 5percent loss of hatchability can go unnoticed.However, a 5 percent loss is 100 percentprofit, and conditions that cause a 5 percentreduction in hatchability also contribute tohealth problems in successfully hatchedchicks.

    Candl ingAll incubated eggs will not hatch. It is

    probable that only 90 percent or less ofincubated eggs are fertile. Removal of eggsthat can be identified as infertile or deadeliminates possible sources of contaminationfrom the incubator. Candling can be used to

    identify some of these eggs.Shining a light through the egg to observe

    embryo development is called candling.White or pale eggs are more easily candledthan dark or speckled eggs. Many people usesmall flashlights with lenses the size of anickel that can be focused to candle eggs.Excellent candlers also can be purchased at areasonable cost. Simple candling devices canbe made by inserting a light into a containerand cutting a small hole to emit light, or bytaping a cone formed from several thick-nesses of paper over the lens of a bright light

    projector. The hole that allows light to passfrom the tip of the cone should be the size ofa dime or quarter (depending upon the sizeof the egg).

    In a dark room, hold the egg to the light ofthe candler to observe the contents of theegg. Cooling that occurs for short periods(less than 10 minutes) during careful exami-nation of eggs does not harm the develop-ment of the embryo. However, limit theexposure of the egg to the hot light source.Even a brief period at 104 degrees F kills all

    embryos.The presence of embryos can be confirmed

    easily after 8 days to 12 days of incubation.The embryo is located in the large end of theegg, where blood vessels radiate under thesurface of the shell. The embryo appears as adark spot that becomes larger as incubationprogresses. Eventually only a dark mass andthe air cell are seen. An infertile orunincubated egg brightly transmits light incomparison. Remove infertile or nongrowingeggs from the incubator. If questions ariseabout candling, contact someone with

    experience for advice.Dead embryos will sometimes appear as a

    ring or smear of blood in the egg or a darkspot dried to the inside of the shell. Theliving embryo will appear as a dark spot inthe large end of the egg surrounded by afaint outline of blood vessels. The bloodvessels will appear firm and distinct. Afterembryo death, the embryo no longer growsand the blood system fades.

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    Retain records of egg infertility or embryodeath. Some mortality can be expected,however, unusual occurrences of mortality orcertain characteristics of the mortality can beindicators of practices that can be correctedto improve hatchability.

    Hat ch St ageThe hatch stage refers to the final 2 days to3 days of incubation. Chicks hatch out of theshell during this stage. Do not turn the eggsduring the last 3 days to 4 days of incubation.Transfer eggs to a dedicated hatcher at thistime. If a hatcher is unavailable, remove theeggs from the turner and lay the eggs in thehatching basket or place on cloth or roughpaper (not newspaper) in the incubator.Make sure that the paper does not obstructairflow, contact the water, or contact theheating element. Temperature should remain

    at 99.5 degrees F and increase the humidityto at least 90 degrees F wet bulb. Humiditycan be increased by adding either a wetsponge or wet paper towels to increase theevaporative surface in the incubator. Thechicks should start to pip within a day of theincubation period listed for the species inTable 1.

    When Chic ks Hat chThe hatching process requires great

    exertion by the chick. The chick progresses

    through periods of activity followed bylengthy periods of rest. The entire hatchingprocess requires 10 hours to 20 hours. Do notbe concerned about the time a specific chickrequires to hatch unless the process exceeds20 hours.

    Once chicks successfully leave the shellthey should remain in the incubator untiltheir feathers are dry. Ventilation should beincreased. When more than 90 percent of thechicks are dry they should be removed fromthe hatcher. Excessive time in the incubator

    can dehydrate chicks. Remove chicks to awarm brooder and provide them with waterand feed.

    Eggs that remain unhatched for 1 daybeyond the predicted incubation periodshould be discarded. Attempts to help achick free itself from the shell often areunsuccessful. Chicks too weak to hatchthemselves usually do not live. If they live,they usually will not thrive. Dispose of weakor deformed chicks humanely. These chicks

    should never be used for breeding purposesbecause these traits could be transmitted

    genetically to their young.

    Embr yo Mor t a l i t y (Deat h)Unsuccessful hatches can be caused by

    infertile eggs or embryo mortality. Each ofthese conditions can be diagnosed aftercandling and after hatch. Examine eggs thatdo not hatch to estimate whether infertility orembryo death is the basis for hatch failure.Keep records of the time of embryo death;such records can suggest changes in hus-bandry that can increase profitability. Asample record form for hatch and fertilityfailures is in Appendix B.

    Embryo death predominately occurs attwo periods during incubation: within thefirst 3 days of incubation and within the last3 days immediately before a hatch.

    Early embryo death occurs during forma-tion of embryonic organs. Of all the eggsdetermined to be fertile by candling at one-third of incubation, 88 percent to 93 percentshould continue to develop.

    Incubat ion Remind ersC Locate the incubator in a room w i th a constant t emp erature,

    away from draf ts and di rect sunl ight .

    C Sanitize the incub ator.

    C Ensure that th e hum idi f ier and w et bulb w ick are in w orkingorder.

    CWash hands before touching eggs. Keep germ s, di r t and oi laway from incubat ing egg s.

    C Only incub ate egg species w ith similar incub ation leng ths at

    the same t ime in o ne incubator.

    C The sm al l end of the egg should not be higher than th e large

    end.

    C Keep a d ai ly record o f incubator data.

    C Check tem perature dai ly and keep i t at 99.5 d egrees F to 1 00degrees F.

    C Veri fy that the w ater t roug h is ful l and hum idi ty measures86 d egrees F to 8 8 d egrees F w et bu lb.

    C Turn eg gs at least f ive t im es a day unti l the last 3 days beforehatch.

    C Increase venti lation during the last one-third of the incubationperiod.

    C Do no t t urn fo r the f inal 3 days. Provide a c loth or roug hpaper surface upon w hich chicks can walk.

    C Increase wet bulb to 90 degrees F in the hatcher.

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    Death immediately before a hatch occursduring the transition betweenliving in an egg to living on theoutside. The chick can have diffi-

    culty positioning for pipping,absorbing the yolk sac, orchanging to breathing air.Sometimes humidity control

    can be implicated in some ofthese problems. An overall hatch

    of more than 85 percent to 90percent can be achieved.

    Collect and examine all unhatchedeggs to determine the cause of hatch

    failure. An appropriately developedchick within the egg will show

    certain characteristics. Normallythe head is under the right wing.The air cell will be large enough to

    allow the chick to position correctly

    for hatching. The shell membranesshould not dry to the chick during hatch.Note any dryness. Note the condition of the

    beak, wings and legs for proper form. Allabnormalities should be recorded andanalyzed to determine if hatch failure re-sulted from fertility or environmental prob-lems that can be corrected by changingmanagement procedures. Nutrition can be afactor in fertility and hatchability problems,as recognized by the National Research

    Council (Appendix C).

    Examine the eggs that fail to hatch byremoving the top of the egg at the large end.Carefully examine the contents and classifyinfertile or dead embryos using the designa-tions listed in Table 2.

    Use the Hatchability and MortalityRecord (Appendix B) to calculate thepercentage fertility, percentage hatchabilityand percentage of total eggs hatched. Thesenumbers will help in evaluating hatchefficiency. Any change in these figures, or a

    change in the distribution in mortalityrecords are early warnings to correct smallproblems before they become serious.

    Table 2. Incubat ing and Hatching Egg and Chick Classificatio n.

    Cu l led eggs Cracked , m i sshapen o r o the rw i se no t li ke ly t o hat ch .

    In fer t i le eggs Determined to have no germ. Or ig ina ll y in fer t i le . These eggs are c lear during candl ingand show no evidence of blood or embryo development.

    Ea rl y dead Embryos d ied du ring t he f i rst quar te r o f incuba t ion . Some o f t hese can be de tec tedand rem oved during candl ing. These eggs wo uld be fert i le and could show a dead

    early emb ryo, show no developm ent, development b ut no blood , or a blood r ing.

    M i dd le dead Embryos d ied a f t er t he ea rly pe ri od bu t befo re t ransfe r.Lat e d ea d Em b r yo s d ie d d u rin g th e h at ch ph ase o f in cu b at io n .

    M a lf orm e d Em b ryo s t hat h ave an o b vio us d ef orm it y.

    M a lposi t ioned Embryos no t pos it i oned co r rect l y f o r hat chi ng .

    Live p ip s Ch ick s t ha t h ave p ip p ed an d are livin g , b u t n o t h at ch ed .

    D ea d pip s Pip p ed c hick s t h at d ie d bu t a re n ot m a lf o rm e d o r m alp o sit io n ed .

    Ro ts In fected o r con t am inated egg s.

    Cu lle d ch ick s Ch ick s t h at h a t ch ed b u t a re u n so u n d .

    G o od ch ick s G o o d q u alit y, he alt h y n o rm a l ch ick s.

    Table 3. Possible Causes of Hatching Problems

    Observat ion Possib le Causes

    Egg s Exp lod ing Dir t y eg gs

    Improp erly cleaned eg gsDirty incubator

    No em b ryo nic d evelo pm en t In fer tile eg gRough handl ing of eggs

    Incubat ion temperature too highIncubat ion temperature too lowEggs stored too long

    8

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    Table 3. Possible Causes of Hatching Prob lems (cont inued )

    Observat ion Possib le Causes

    N o em b ryo nic d evelo pm en t Eg g s st ored im p ro perlyBreeders stressedToo many hens per rooster

    Old or un heal thy hens or m alesInbreeding

    Disease

    Bloo dring Old egg sEarly dead Incubat io n tem peratu re too h ig h

    Incubat ion temperature too low

    Dead embryos, second w eek Incubat i on t emperatu re t oo h i ghIncubat ion temperature too low

    Electric pow er fai lureEggs not t urnedInbreeding

    Infect ionPoor n utr i t ion of breeders

    A ir cell too sm all Hum id it y too h ig h

    A ir cell too large Hum id it y too low

    Chicks hat ch ear ly Sm all egg s

    Dry ch icks Tem peratu re to o h ig hBloody navels Hum id it y too lowChicks too small

    Chicks hat ch late Large egg sOld eggs

    Temp erature too lowHumid i ty too h igh

    Ch icks dead a f t er p ipp i ng she ll Eggs no t t u rned f i rst 2 w eeksThin-shelled eggs

    Incorrect tem perature dur ing incubat ion

    Temp erature too high d ur ing incubat ionHumidi ty too high dur ing incubat ionHumid i ty too low dur ing incubat ionInfectio n, d isease

    Unhealed navel Tem perat ure too low during incubat io n

    M ushy or w ater -logged ch icks W ide temperature var ia t ion in incubatorHumidi ty too high dur ing incubat ionPoo r venti lation

    M a lf orm ed leg s an d to es Im p ro per tem p erat ure du rin g in cu bat io nImproper humidi ty dur ing incubat ion

    Legs also m ay be harmed by hatching or holding chicks on a sm ooth surface

    W eak ch icks Tem peratu re too h igh o r low

    Old eggsPoo r venti lation

    Gasp ing ch icks DiseaseBronchit is

    New castle disease

    M alposit ions Tem peratu re too h igh o r low

    Turning inadequateLarge end of egg not up w hen set

    Old or poorly handled eggsPoor breeder nut r i t ion

    9

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    APPENDIX A: INCUBATOR DATA CHART

    Turner Wor ks1 Tem perat ure Wet Wat erDay # Dat e 1 2 3 Room Incubat o r Bu lb Checked Candling Rem ar ks

    1

    2

    3

    4

    5

    6

    7

    8

    9

    10

    11

    12

    13

    14

    15

    16

    17

    18

    19 XXX XXX XXX

    20 XXX XXX XXX

    21 XXX XXX XXX

    This record is im port ant. Keeping data w i ll help prevent p roblems from developing du r ing incubat ion.1 Check th e turner t hree t imes each day except d ays 19 throug h 2 1. Eggs are not turned on these days.

    10

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    11

    APPENDIX

    B:HatchabilityandMorta

    lityRecord

    Set

    Candling

    Eggs

    Dead

    M

    alform

    ed/

    Pips

    Chicks

    Percentage

    ID#

    Date

    Date

    Culle

    d

    In

    fertile

    Early

    M

    iddle

    Late

    M

    alposition

    Live/Dead

    Rots

    Cull

    Good

    Fertility1

    Hatch2

    Total3

    /

    /

    /

    /

    /

    /

    /

    /

    /

    /

    /

    /

    /

    /

    /

    /

    /

    /

    /

    /

    /

    /

    /

    /

    Thisrecordisimportant.Keepingdatawillhelpidentifyproblemsw

    ithbirdhusbandryandincubation.

    1Fertility(%)=(FertileEggs/Eg

    gsSet)x100%.

    2Hatchability(%)=(GoodChic

    ksHatched/FertileEggs)x100%.

    3TotalEggsHatched(%)=(Go

    odChicksHatched/EggsSet)x100%

    .

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    12

    Appendix C: Signs of Def ici ency in t he Embr yo

    Nut r ient : Def iciency Signs:

    V it am in A Deat h at ab ou t 4 8 h ou rs o f in cu bat io n f ro m failu re t o d evelo p t he circu lat or y system ; ab no rm ali-t ies of kidneys, eyes and skeleton

    V it am in D Deat h at ab ou t 1 8 o r 1 9 d ays o f in cu bat io n, w it h m alp osit io ns, so ft bo nes, an d w it h a d efect ive

    upper m andib le prom inent .

    V it am in E Early d eat h at ab ou t 8 4 to 96 ho urs o f in cu bat io n, w it h h em o rrh ag in g an d circu lat or y f ailu re( im pl icated w i th selenium).

    V it am in K No ph ysical d efo rm it ies f ro m a sim p le def icien cy, n or can th ey b e p ro vo ked by an tivit am in s, b utmo rtal i ty occurs betw een 18 d ays and hat ching, w i th variable hemo rrhaging.

    Th iam in Hig h em bryo nic m or t alit y d urin g em erg ence bu t n o o bvio us sym pto ms o ther t han po lyn eu rit is in

    those that survive.

    Ribof lavin (Vitam in B2) M or ta li t y peaks a t 60 hou rs, 14 days, and 20 days o f i ncuba t ion , w i t h peaks p romi nen t ea rl y as

    def ic iency becom es severe. Altered l im b and m andible development , dw arf ism and clubbing o fdow n are defects expressed by em bryo.

    N iacin Em bryo read ily synt hesizes suf ficien t n iacin fro m t rypto phan . Vario us b on e an d beak m alfo rm a-

    t ions occur w hen certain antago nists are administered dur ing incubat ion.

    Bio t in Hig h death rate at 19 days to 21 days o f incubat io n, parro t beak, chondrodyst rophy, severalskeletal deformities and webbing between the toes. Perosis.

    Pa nt o t he nic a cid D ea t hs a p pe ar ar ou n d 1 4 d ays o f in cu b at io n , a lt h o ug h m a rg in al le ve ls m a y d e lay p r ob le m s u n t il

    emergence. Variable subcutaneou s hem orrhaging and edema; w irey dow n in po ul ts.

    Pyridoxine Early em bryon ic m or talit y based o n ant ivit am in use.

    Fo lic acid M o r talit y at ab ou t 2 0 d ays o f in cu bat io n. Th e d ead g en erally ap pear n orm al, b ut many h ave

    bent t ib iotarsus, syndacty ly and m andible mal form at ions. In p oul ts, mort al ity at 2 6 days to 28days of incubation with abnormalit ies of extremities and circulatory system.

    Vi tamin B12

    Mortal i ty at about 20 days of incubat ion, wi th atrophy of legs, edema, hemorrhaging, fat ty

    organs, and head betw een thighs malposi t ion.

    M a ng an ese Deat hs p eak prio r t o em erg en ce. Ch on dro dyst ro ph y, dw arf ism , lo ng b on e sh or ten in g, headmalform at ions, edema, and abnorm al feather ing are prom inent. Perosis.

    Zinc Deat hs prio r to em ergence, and t he appearance o f rum plessness, dep let io n o f verteb ral co lum n,eyes und erdevelop ed and l imbs m issing .

    Copper Deaths at early b lo od st age w it h no m alfo rm at ions.

    Iod ine Pro longat ion of hat ch ing t im e, reduced thyro id size, and incom plete abdom inal closu re.

    Iron Low h em atocrit ; low b lood hem og lob in ; poo r ext ra-em bryon ic circu lat ion in cand led egg s.

    Selen ium High incidence o f dead em bryo s ear ly in incubat ion .

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    Resour cesPublications

    Mullin, J.M. and P.M. Boehmer. Gamebird Propagation. Wildlife Harvest Publications,Inc., 2000.

    Hatching Manual. Lyon Electric Company, Inc., 1988.

    Stromberg, Janet. A Guide to Better Hatching. Stromberg Publishing Company, 1975.Circular 530, Incubating Eggs of Domestic Birds. Cooperative Extension Service,Clemson University.

    B-1123, Care, Management, Propagation - Japanese Quail (Coturnix). Texas Agricul-tural Extension Service.

    Leaflet No. 519, Raising Guinea Fowl. U.S. Department of Agriculture, U.S. Gov-ernment Printing Office.

    Circular 514, Raising Bobwhite Quail for Commercial Use. Cooperative ExtensionService, Clemson University.

    Leaflet 21046, Raising Game Birds. Division of Agricultural Sciences, University ofCalifornia.

    Leaflet 21321, Raising Chukar Partridges. Department of Avian Sciences, Universityof California.

    Bulletin 878, Game Bird Production and Health. The Cooperative ExtensionService, University of Georgia.

    Wall charts

    Cherms, F.L. Embryonic Mortality of Turkey Wall Chart, Nicholas Turkey BreedingFarms, Inc., Sonoma, Calif.

    Embryo Development Chart, Jamesway Incubator Co., Monroe, N.C.

    Poster 21559, The Australian Emu: Embryonic Development, ANR CommunicationServices, University of California. http://anrcatalog.ucdavis.edu.

    Poster 3321, Development of the Pheasant Embryo, ANR Communication Services,University of California. http://anrcatalog.ucdavis.edu.

    Video

    V86-W, Hatching Egg Breakout Video, ANR Communication Services, University ofCalifornia. http://anrcatalog.ucdavis.edu.

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    Educational programs of the Texas Agricultural Extension Service are open to all people without regard to race, color, sex, disability, religion, age or national origin.

    Issued in furtherance of Cooperative Extension Work in Agriculture and Home Economics, Acts of Congress of May 8, 1914, as amended, and June 30, 1914in cooperation with the United States Department of Agriculture. Chester P. Fehlis, Deputy Director, Texas Agricultural Extension Service, The Texas A&MUniversity System.2,000, New PS 3

    Produced by Agricultural Communications, The Texas A&M University SystemExtension publications can be found on the Web at: http://texaserc.tamu.edu

    For more information about sources and suppliers of incubators and supple-mental equipment, contact the local office of the Texas Agricultural ExtensionService or contact Lee Cartwright in the Poultry Science Department, 107 KlebergCenter, 2472 TAMU, College Station, TX 77843-2472, telephone (979) 845-4319,fax (979) 845-1921, e-mail [email protected]