Heat Stress Management in Poultry world .pdf

Heat stress management is very important during hot days . Stress can lead to death

2. What is heat stress?
Birdsare‘heatstressed’iftheyhavedifficultyachievingabalance
betweenbodyheatproductionandbodyheatloss.Thiscanoccuratall
agesandinalltypesofpoultry.
Inthe‘Thermo-neutralzone’,birdscanloseheatatacontrolledrate
usingnormalbehavior.Thereisnoheatstressandbodytemperatureis
heldconstant.Whenconditionsmeanthe‘uppercriticaltemperature’is
exceeded,birdsmustloseheatactivelybypanting.Pantingisanormal
responsetoheatandisnotinitiallyconsideredawelfareproblem.
Butastemperaturesincrease,therateofpantingincreases.Ifheat
productionbecomesgreaterthan‘maximumheatloss’eitherin
intensity(acuteheatstress)oroverlongperiods(chronicheatstress),
birdsmaydie.Thebodytemperatureofthebroilermustremainvery
closeto410C(1060F).Ifbodytemperaturerisesmorethan40Cabove
this,thebirdwilldie.

5. Howdobirdsloseheat?
Heatcanbelostinavarietyofways.Threenormalmethodsofheatlossare listed
below.Birdsmodifytheirbehaviortostayinthe‘thermo-neutralzone’.
●Conduction–heat will transfer from one surface in contact with another
surface, for example, if the birds are seated on litter that is cooler than their
bodies. However, the litter immediately under the birds soon assumes a
temperature close to that of the body.
●Convection–heatlosswilloccurfromthenaturalriseofwarmairfrom
aroundahotbody.Providingmovingaircanassistconvection,butonly if the
air moves fast enough to break down the boundary layer of still air that
surrounds the body.
●Radiation–Heat will be lost from the body by radiation if the surrounding
surfacesarebelowbirdsurfacetemperature.Conversely hot walls and roofs
may radiate heat to the bird surfaces.

6. Mechanism of Heat Stress
TheneuroendocrinesystemplaysaverysignificantroleinHSresponseby
inducingtheautonomicnervoussystem(ANS)thatoftenregulatesfightand
flightsituationsinlivingorganisms.
InresponsetoHS,theANStakeschargeandtriggerstachycardia(increased
heartbeat),increasesrespirationrateandenhancesthebloodflowtowardthe
bodyperipheries(skin)formaximumheatlosstomaintainbody
temperature.Italsopromotesthebreakdownofglycogenintoglucosein
musclesandreducestheircapacitytostoreenergy.
HSalsoactivatesthehypothalamic-pituitary-adrenalaxis(HPA)alongwith
thesympathetic-adrenal-medullaraxis(SAM),whichpromotesthereleaseof
glucocorticoids,vasodilation,lipolysis,andproteolysisinmuscle.

14. Steps to Combat Heat Stress inPoultry
Theaimofadoptingmeasurestocombatheatstressisnotonlyto
keepbirdsalivebutalsotogetproductionoutofthemtoachieve
targetedfiguresi.e.numberofeggfromlayersandabetterbody
weightatparticularagewithspecificFCRinbroilers.
Following steps will help to combat heat stress inPoultry Farming in
summer:
-Housing Management
-Feed Management
-Water Management
-Miscellaneous Management
-Disease Management

42. References:
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Gonzales E, editores. Fisiologiaaviáriaaplicadaa frangosde corte. 2 Ed. Jaboticabal
:Funep-Unesp; p. 209-230.
2. Mohan, J. (2006). Thrust Areas for Mitigation of Stress in Poultry. Poultry
Research Priorities to 2020, 122, 147.
3. Olanrewaju, H. A., Thaxton, J. P., Dozier, W. A., Purswell, J., Roush, W. B., &
Branton, S. L. (2006). A review of lighting programs for broiler production.
International journal of poultry science, 5(4), 301-308.
4. Puvadolpirod, S., & Thaxton, J. P. (2000). Model of physiological stress in
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5.(Lara, L. & Rostagno, M., 2013. Impact of heat stress on poultry production.
Animals, Volume 3, pp. 356-369.)
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