Hatchability Determining Factors

Fertility Metabolism of chick embryo Temperature during incubation Humidity during incubation Incubation at high altitude Air requirement during incubation

cont..

Egg selection & handling of hatching eggs

Position of egg during incubation Nutrition Genetics Diseases Other factors affecting hatchability

1-Fertility What is Fertility

Fertility refers to the capacity to reproduce Role of male in fertility

Induce the sperm in female reproductive system after mating Fertile eggs start after 2 week of mating(In some cases fertile eggs start after 24 hours of mating ) Infertile eggs start --- after 1 week of removal of male from flock

Role of female in fertilityAfter receiving sperm fertilize egg in female reproductive tractSafe the germ plasma after fertilization

Conti...

Factors affecting the fertilityMale to female ratio (number of female mated to one male)Male to female ratio (1:5)Age of breederMating behaviorSaving eggs for hatchabilityManagement Practices

Losses of Infertility Chances of infertility 10% (USA based data)Economic losses Occupy valuable incubator spaceRequire time consuming labor & handling Hatchery maintaining cost

Important Considerations Fertility can’t be predetermined

Can’t differentiate b/w fertile & nonfertile eggs prior incubationWith Special light system-check after few hour of incubationwith Commercial chandlers- check after several days of incubation

Egg must be broken to determine true fertilityCandling is crude method

Fertility inheritedStrains differenceIndividual differenceBetter fertility through genetic selection in breeds

2-Metabolism of Chick Embryo What is Metabolism

Necessary for growth & lifePhysical & chemical processes

occurring within a living cell or animals that are necessary for life

Anabolism (biosynthesis)Catabolism (breakdown)

Cont..

Metabolism in chick embryoMetabolic rate of chick embryo is the result of temperature Higher optimal temperature accelerate growthLower temperature retard / delay growth As metabolism cell of embryo demand more O2 to metabolize the fats, CH2O & other components which in turn produce CO2 & water, or vice versa Balance reversible reaction is a indicator of correct temperature Optimal temperature of setter is 99.7oF (37.5oC)

Cont..

Importance of water loss from eggTo control the loss of metabolic water fromMust maintain the hatchery humidity 50-60% Egg water elimination enhance O2 entrance

Problems of high humidityLess water elimination causes Less O2 entrance in eggReduce O2 suffocate the embryoCause— Early embryonic death Chic hatch late Week Chicks

Cont..

Problems of high humidityMore H2O will be eliminated from embryoMore Water loss from yolk & albumenCause- Early embryonic death Chick hatch late Week & small Chicks General loss of whole egg---12% (within 19 days)Daily losses ----- 0.632%(at 50-60% humidity

Cont..

Egg weighing to determine weight loss

weigh the empty tray weigh the tray with eggsweight the tray at the end of 19th dayYou can also weigh at any day of

incubation calculation----

3-Temperature During Incubation What is temperature

Temperature is a measure of the average heat or thermal energy of the particles in a substance

Physiological ZeroTemp. below which embryonic growth is arrested 750F (23.9 0C)PZ temp. varies with strains & varieties

Optimum temp. for IncubationRange b/w 950 to 1050F (350 t0 40.50C)

Consequences of Low & High Temp. during Incubation

Conti… Three Optimum Temperature

Prior to egg laying body temp. of Broody hen 950 to 1070F (46.60 to 41.70C) during first 19 day of incubation 99.50F(36.70C) during 20th & 21st days of Incubation890 to 990F (36.70C to 37.20C)

Conti… Optimum incubation temp. is not same

for all eggs due to following factors …..

1-Egg size2-Shell quality3-Gnetics (breed/ strain)

4-Age of when it is set5-Humidity of air during incubation

Conti… Embryonic effect from

Overheating Exposure of 16 hours embryos for 24 hours to 1040F (400C)-No detrimental effect on hatchability Exposure for 6 hours to 1100F (43.30C) .. Hatchability Exposure for 9 hours to 1100F (43.30C) .. Severe Hatchability Exposure for 3 hours to 1150F (46.10C) ..orExposure for 1 hours to 1200F (48.60C) .. Killed all embryossevere heat stress causes …clubbed down & unsteady gait

Conti…

Embryonic effect from coolingFirst 3 day quite resistant against low temp. Hatching chick are more resistant to cold than heat

Consequences of cooling Lengthen the incubation period

Increase the chances of malposition of embryoMajor prob. due to reduction in 20C for last day days

Conti…

What happen when electric power failsHeat not equally distribute (due to fan )More heat will be at topAt top—more heat-embryo overheated At bottom—less heat/ chilling of embryos

So emergency electric supply is necessary for successful hatchery operation

Conti…

Thermometers should be checked oftenTo check the ThermometersPlace in refrigerator for 30 min & shake mercury down or Place in warm water & shake the mercury down

Reuniting separated mercury when mercury in thermometer separates, temp. reading s are incorrect

4-Humidity during Incubation What is Humidity

Percentage of moisture in air Measuring relative Humidity

HygrometerBy comparing the thermometers recorded by wet & dry bulbsDry bulb…..recorded normallyWet bulb…..recorded ..bulb covered with a water-moist wick

Hygrometer

Conti…

Consequences of high humidity in setter (1-19 days)Lengthen the incubation time

Consequences of low humidity No pipping due to beak sticking

Egg shell quality & humidity requirementPoor shell quality-more moisture movement/ losses Thick dense shells –low moisture movement/losses

Conti…

Cracked eggs & humidity requirement2% egg cracked -out of total egg set1.1% -Cracked when trayed , 0.9% cracked at transferMore Humidity due to cracked eggsRequire more air flow for normal O2 requirementMore losses due to CO2

5-Incubation at High Altitude What is Altitude

Distance measured above sea level 1944 North Reported the difference of

hatchability at different altitudes Hatchability & Altitude is inversely proportional Highest at sea level up 90-92% Optimum altitude

2500 ft (760 m)hatchability 80-85%at 3500 ft (1067 m) –acute problems

Conti…

Problems at high altitude Reduced wt of O2

Low air pressurewhat happen low availability of O2

lower hemoglobin concentration in bloodParti. at 13-14 days of incubationlower / delayed hemoglobin productionlow supply for embryo developmentresult …….heavy embryonic death

Conti…

Increasing air pressure restore normal hatchIncrease air pressure artificially Pressurized atmosphere in incubator

Oxygen injection a better methodConcentration of O2

Hatchability can be improved by supplying O2 How to inject oxygen

Inject both in setter & HatcherApparatus to determine the %age of O2 conc.

6-Air requirement during Incubation Composition of air

Oxygen …………21%

Oxygen in air & its importance It is impossible to increase the O2 in incubatorEach1% drop in O2–decreses the 5% hatchability

Conti…

Normal air supply generally adequateWith the increase of age –embryo require more O2 & (more CO2 given off) The process of O2 requirement increase 100 times at 21st day as compare to 1st day Generally O2 requirement increases 8 time after every 3 days of incubation life

How we increase the O2 in incubatorsBy increasing air circulationBy O2 supplying (not applicable / expensive)

Conti..

Gaseous exchange during incubation per 1000 eggs Day of Incubation Absorption of O2

ft3Expulsion of CO2

ft3

1 0.5 0.295 1.17 0.5810 3.79 1.9215 22.70 11.5018 30.00 15.4021 45.40 23.00

Conti…

Carbon dioxide toleranceAt laying CO2 release from egg and turn egg contents to alkalineNormal pH of Egg contents at laying…. Albumen pH 7.6 after one week 9.5Yolk pH 6.0 after one week 6.8CO2 concentration must be in range limit in setter & hatcherTolerance level first 4 week……0.03%At 1% …Significant reduction in hatchabilityAt 5% .... Completely lethal for hatchability

7-Egg selection & care & storage, handling of

hatching eggs Exterior quality

Genetic parental characters has great role in production of good hatching quality eggEgg size Normal size (53 gm, WLH) -Range 54-64 gmEgg shape3 types (Oval, Oblong & round)oval is desirable shapeOblong & round not desirable

Conti…

Egg shell colorWhite vs white with tintsDark brown vs light brown Shell textureShell thickness …0.33 – 0.35 mmweak shell thickness….. 0.27 mmThin shell thickness was due to deficiency of Vit D or CaSmooth shell vs Porous shell

Conti…

Interior qualityPosition of yolk Yolk should be in center of hatching eggs Yolk was not in center in older egg- Causes of low hatchability was due to sticking of embryo with shell Size of air shellLarge air shell has low hatchability which was due to older egg Blood & meat spots ..has no any effect on hatchability Poor shell condition A small crack has zero hatchability

Conti…

Care & Storage of hatching eggsHatching egg quality may be deteriorate due to following reasons…Improper temperatureImproper HandlingImproper humidityAge of eggsCleanliness of shell

Position & Turning of egg during incubation Broader end at top due to air cell

If pointed end at top 60% .. Wrong position& 10% dead embryos

Egg rotate at 45 degree Clock wise rupture the allantoises

membranes Angle turned to each

side of vertical Hatch of fertile eggs

200 69.3300 78.9400 84.6

Conti…

Daily turning of egg and hatchability

Time Turned daily Hatching of fertile eggs

2 78.14 85.36 92.08 92.210 92.1

Nutrition Vit. A……Failure to develop the blood system

Embryonic malpositions Vit. D……Ricket (lack of P) Stunted chicks

Soft bones resulting from improper Calcification Vit. E…….Reduced fertility, Inadequate

embryonic vascular system, embryonic mortality 1-3 d

Vit. K……Prolonged embryonic blood clotting time Hemorrahages & blood clots in embryo & Extra embryonic blood vessels. Hemorrhagic syndrome of embryo & Chick

Conti…

Riboflavin……High mortality 9-14 days. Edema, Atrophied leg muscles, clubbed down, curled toes, enlarge of sciatic nerve sheaths, reduced hatchability 2 after breeder ration become deficient.

Pantothenic acid…… Abnormal feathering, S/c hemorrhages in embryo, Chick hatch in weak condition & most fail to survive.

Biotin…….Perosis, Short long bone (micromelia), shortended & twisted bone of feet, wing & skull. High mortality b/w 1 -7 days.

Conti…

Vit. B12Embryonic mal position, edema, short beak, poor muscles development, High embryonic mortality 8-14 days

Folacin Similar to biotin deficiency, Chick die after pipping the shell

B6Reduced hatchability

Contii….

Calcium……Ricket Reduced hatchability, Short & thick leg & wing & lower mandible,

Pliable peak, leg & neck, edema Phosphorus…Ricket, soft leg & beak, high

embryonic mortality b/w 14-16 days Manganese…skeletal Abnormalities, Short

wing & legs, abnormal head & parrot beak (Chondrodystrophy)

Imperfect development of inner ear. Retarded growth, Edema

Contii…

Zinc….Micromelia , skeletal deformities (absence of rump, wing, legs & toes), underdeveloped eyes, newly hatch chicks are weak, & cannot stand, eat or drink, chick mortality increases soon after hatching.

Selenium…subcutaneous fluid, exudative diathesis (edema), degeneration of pancreas, reduced hatchability, selenium deficiency enhanced when the breeder diet is low in vitamin E

Excessive items

Selenium….toxic at high level, edema, crooked toes & high embryonic mortalities

Nicarbazin…….Brown eggshells lose their pigment, hatchability decreases up to 32%

Genetics Impossible to predetremined sex

No method to determining the sex of living embryo at the time the egg is laidShape , position of air cell, gravity or other factors has no any effect on sex ratio

Sex ratio Following factors effect on sex ratioGenetics……..strains' & varieties Lethal genes…some lethal genes are associated with sex Physical factors..environmental condition Time of egg laying..more male in hot weather Correct sex ratio….No fix ratio due variation in egg production

Diseases Diseases of breeder flock affect the

hatchabilityPullorum disease Infectious bronchitisArzona disease Newcastle diseaseFowl typhoid Avian Encephalomyelitis Paratyphoid Mycoplasma gallisepticum Aspergilliosis Mycoplasma synoviae Omphalitis Aflatoxisis (toxin poisoning)Escherichia coli infectionLaryngotracheitis

Other factors affecting hatchability

Egg laying pattern and hatchability 1st & 1st week had low hatchability Early & Later laid has low hatchabilityMaximum Hatchability at 13 – 14 week of egg production

Egg in start of clutch has low hatchability as comp. to end of clutch High production has higher hatchability as compare to low & medium production

Conti…

Weather affects hatchabilityLower hatchability in extreme weather condition b/c heat & cold effect breeder performancelow intake, Hatchability..5% less in may & June

Factors affecting the length of incubation periodCertain diseases.. Increase incubation periodLonger egg formation time..Reduce Incub. period WLH has lower incubation period than meat type breeders Egg produced in warmer season has shorter incubation

Conti…

Smaller breeder has short incubation period

Similarly small egg hatch sooner than larger egg

Noise & hatchabilityNo effect on hatchability even sonic boom

Conti…

Age of breeder affects hatchabilityIncreasing age of breeder effect the hatchabilityOlder breeder take more egg formation time with strong egg shell ..increase hatching timePosition of embryo in eggNormal position…Embryo with head in larger end of egg (near air cell) & with its head under right wing

Conti..

Description of some male positionChances of malposition 1-4%Head between thighsHead in small end of eggHead under left wingFeet over headBeak above right wing instead under

Hatching %age of malposition chick