stress management in Poultry, causes and effects on growth and production, their mitigation strategies.

1. Credit Seminar
on
Bihar Veterinary College, Patna
Bihar Animal Sciences University, Patna, Bihar

2. Stress
The term “Stress” is used to describe the
detrimental of variety of factors on the
health and performance of poultry.
Birds have limited resources for growth,
reproduction, response to environmental
changes and defense mechanism

3. Stress
Climatic
Extreme heat/
cold
Humidity
Physiological
Rapid growth
High egg production
Process of sexual maturing
Molting etc.
Physical
Catching
Handling
Transport
Injections
Ion mobilization etc.
Social
Over crowding
Various age/ size grouping
Psychological
Fear
Harsh care takers
Abrupt changes etc.
Environmental
Poor ventilation
Ammonia gas
Pollutants
Wet liter
High light intensity
Nutritional
Nutrient shortages
Feed intake
problems
Adulterated feed
Toxic
Normal physiological limits
Optimum functions

4. Tropical countries- Heat Stress Temperate countries- Cold Stress
Heat Stress Vs Cold Stress
Which one is more
dangerous?
Cold Stress is more
dangerous than Heat
Stress
Humidity and Temperature
requirement for poultry

5. Birds takes more feed
More metabolic heat to maintain body temperature
As a result more amount of subcutaneous fat deposition
(More than 60% of fat)
Over body weight and less production
Results in long term problems and huge economic loss
Cold stress

6. Chick requires 400C during 1st and 2nd week of age
(Hypothalamus is poorly developed in chicks)
But optimum temperature for adult birds is 19 to 240C
(Normal body temperature is 41 to 420C)
Chick Vs Adult birds

7. Birds are Homeothermic
Body temperature -
41 to 420C
Regulated by Hypothalamus
– act as a thermostat
Thermoregulation in Birds

8. Can with stand only narrow temperature range
High body temperature when compared to other species
Absence of sweat gland
Feather cover
Subcutaneous fat
Features of Thermoregulation in birds

9. Heat Stress
Physiological condition in which body is
not able to maintain balance between
heat production and body heat loss
High ambient temperature and high
humidity is one of the most important
stress

10.  Birds are susceptible to high
environmental temperature due to
• Absence of sweat gland
• Feathered body
• Fatty nature
• High body temperature
 Broiler than layers
 Male broilers than layers
 Good layers in cages than layers in Deep
litter system
Susceptibility

11. • Bird is producing heat through Metabolic
processes and Muscular activity
• Thermo neutral Zone :
Heat production= Heat loss
• 21-24 0C
Heat produced

12. Heat produced in the body is lost
Conduction
Convection
Radiation
Evaporation
Faecal
Excretion

13. Divided into two main categories
Sensible heat loss
Occurs through conduction, convection &
radiation
Ideal temperature for optimum poultry
production is 65-75 0F
Heat loss

14. Insensible heat loss
Occurs through panting (evaporative heat loss)
Begins when temperature reaches 80 0F
Bird can increase respiration rate upto 10 times
normal
Bird can also reduce heat by raising and spreading
their wings
Separating themselves from other birds

15. Diagram of thermo neutral zone
Thermo
neutral
zone
Slow
Panting
Heat
related
welfare
problem
Welfare
problem
exists
Increasing ambient temperature
Lower
critical
temperature
Upper
critical
temperature
Maximum
heat loss
Death from
heat
Normal
behavior
regulates heat
loss
Fast panting
Physical
tiredness
Birds can’t
control body
temperature

16. High temperature leads to:
Panting
Standing quietly
Crouch near wall or wet places
Consuming more water
Spreading of wings
Wetting comb and wattles
Behavioural Changes

17. Reduced appetite
Reduction of egg production
Poor egg shell quality
Less body weight gain in broilers
Reduced feed efficiency
Death

18. Spreading wings Panting
Crouching Wet wattles

19. Eggshell is made up of Calcium carbonate
Calcium carbonate
(Feed)
(Calcium hunger)
(CO2-Respiratory tract)
During summer- Panting occurs
 More amount of CO2 is excreted out resulting in
respiratory alkalosis (HCO3)
 Poor egg shell formation
Physiological Changes

20. More egg breakage during summer season
Egg breakage

21. Site & Planning
Orientation : Long axis should be East-West
Shade: Trees
Air movement: Perpendicular to Prevailing wind direction
Spacing: Recommended design spacing
D= 0.4*H*(L)0.5
H&L are height and length of obstructing building
or not less than 10-12 meters
Housing Management

22. Building width: 10-12 m is preferable
Roof: Gable or shed roof along with ridge vent
to provide an escape for hot air at roof peak is
desirable
Floor: Concrete floors are desirable for easy
Cleaning & Disinfection
Wall: Should be water proof & poor conductor
of heat

23. Insulation: Should be placed below the roof as it will
prevent influx of heat into the building
Painting & White washing: Outside of walls & roofs
should be painted white or covered with material
which will reflect heat
Ventilation- For elimination of already heat produced
proper ventilation is necessary
Not more than 13m wide & 4m in height
Roof overhangs: should be sufficient (3-5ft) to
protect the birds from strong sunrays

24. Sprinklers on roof reduce temperature of shed by 5-
10 0C
Make tree plantation, they act as wind breaker
Maintain grassy lawn around poultry sheds to
reduce reflected radiations
Put the gunny bags on sides of the house and wet
them frequently during hot summer. Wind blowing
over wet gunnies will cool the house

25. Avoid over crowding by increasing floor
space/bird
Arrange free ventilation with open sided
walls and high roof. The minimum height
between the floor and the roof must be 4.0
and 3.5 meters at the ridge and eaves,
respectively

26. Natural Ventilation
 Curtain sided houses rely extensively on natural
air movement
 Located away from obstructions (tree, buildings)
Forced Ventilation
 All air movement is produced by fans in the
building walls
 Houses that use this type of ventilation are also
referred to as controlled environment systems
 Uniform airflow patterns

27.  Most effective method of cooling in low humidity
 Air is drawn through adsorbent, porous cooling pads
or through fan pad system
 Cooling of warm air is attained by its contact with
water
 Air cools and there is increase in RH
 Aspen fiber and corrugated cellulose are two
materials widely used as cooling pads
EVAPORATIVE COOLING

28. Fan Pad System
Hot air Cool air
Cooling pad

29.  The foggers inject fine water particles into
the warm inside air
 As the water vaporizes, heat is absorbed
from the air, lowering its effective
temperature
 Foggers reduce air temperature in the house
on hot days (900 to 950F)
Fan fogger system

30. Fan
fogger
System

31. During summer consumption of feed by birds is reduced
considerably leading to reduced body weight, egg production and
shell quality
Do not offer feed during day time in broilers
Increase nutrient density of feed to compensate for depressed feed
intake
Energy of feed should be reduced. Crude protein content should
not be increased
Similarly 20-30% extra vitamins and trace minerals should be
added to feed
Available phosphorus content of feed should be increased
Feed Management

32. Feed should be given during cooler part of the day
Wet mash by mixing water and supply in feeders
Nearly 10 to 15% of the calories (energy) in the feed,
of carbohydrate and protein origin, may be replaced by
fat/ oil energy, by adding 2 to 3% oil or fat. But this
should not increase the total calories in the feed and
only replace the energy of carbohydrate origin
Fat may be mixed in diet in summer to reduce heat
increment and relive from heat stress

33. Higher fat content of feed also contribute to lower
heat production
Growth rate & feed utilization of heat stressed bird
gets improved
Food intake & growth rate got improved by
increasing ME of diet & decreasing proteins

34. Protein & Amino acid requirement
Protein has high heat increment
Diets containing lower protein levels &
supplemented with limited amino acids,
methionine , lysine gave better results

35. Vitamin Requirement
Decreased nutrient intake at high temperature
decreases intake of micro nutrients
Supplementation of these nutrients is helpful for
maintenance of performance & immune function

36. Vitamin C
Under heat stress, birds are not able to synthesize the
sufficient amount of vitamin C
 Vit C@ 1000mg/kg
Supplementation of ascorbic acid
 Heat resistance
 Carcass quality
 Carcass weight
 Carcass CP content
 Act as antioxidant reduce oxidative injuries
 Reduce mortality

37. Vitamin A
 Detrimental effect on egg production by heat stress
can be alleviated by dietary suppl. of Vitamin A @
8000 IU/kg diet
 For optimal egg production
 For immunity of heat stressed hen
 Alleviate the oxidative injuries induced by heat
exposure

38. Vitamin E
Dietary supplementation of Vit E is beneficial for egg production in
hens
 @250mg/kg – Acute stress
 @65 IU/kg- Chronic heat stress
Supplementation is associated with
 Increase in feed intake
 Increase yolk and albumin solids
 Increase concentration of VLD proteins
 Improve immune system
 Act as antioxidant
 Contribute to integrity of epithelial cells

39. Mineral Requirement
 Blood acid balance is disturbed by hyperventilation
and results in respiratory alkalosis
 Respiratory Alkalosis suppress growth rate & egg
shell quality
 Suppression of growth can be partially alleviated
by supplementation of
 1% NH4Cl
 0.15%-0.6% KCl
 0.2% NaHCO3

40.  Add soda-bicarbonate @ 0.1% for improvement of
shell quality
 Increase the calcium level from 3-3.5% in layer diet
 Supplementation of electrolytes in water enhance
 Water consumption
 Increase tolerance to heat stress
 Improve production performance

41.  Heat stress can induce unfavorable changes in
indigenous bacterial microbiota
 Supplementation of probiotic lactobacillus
strain may enrich diversity of microflora in
chicken
 Restore microbial balance in jejunam & caeca
of chicken
 Reduce harmful effects of heat stress
Other Nutrients & Feed additives

42. Normal ratio of water to feed intake is 2:1 but get
changed 4:1 when temperature is above 270C
Birds drink 4% more water for every one degree
increase in temp. above 270C
Provide plenty of fresh, clean and cool drinking water
during hot weather
The water pipes should not be exposed to sun light
Molasses or jaggery may be added to water
Water Management

43. Water
Water requirement increase during hot periods
6% water intake increase per degree rise in
temperature from that at 200C temperature
25% more drinking space should be provided
Water below body temperature will certainly
aid in heat dissipation

44. Water drinkers should be wide & deep enough so
that birds face is immersed in it

45. For day old chicks provide cool water and electrolytes on their
arrival to farm before offering feed to avoid dehydration after
transportation
Cover water tanks with wet gunny bags to avoid direct exposure to
sun
Increase number of waterers by 25%
Increase frequency of watering
In case of nipple drinkers, insulate nipple pipe with wet gunny cloth
Provide electrolyte (1-2g/liter) in water during hot hours
Addition of 0.25% of salt to drinking water increases water
consumption

46. Beak trimming
 To prevent feather picking & cannibalism
which is more in hot climate
Litter Management
 Is most important step in broiler
management during summer
 Litter should be at least 5 cm depth & in
good condition during summer
Miscellaneous Management

47. Stocking density
 Stocking density should be reduced by 10% in summer

48. Heat stress makes birds more susceptible to various
disease conditions
Disease Management
 Coccidiosis  Mycotoxicosis

49. Most important cause of mortality in chicken
during hot humid season
Rapid screening & detection of moulds should
be taken in feed stuffs
Best control of Mycotoxin formation is to
prevent the development of fungi in feed stuffs
Mycotoxicosis

50.  Control of Mycotoxicosis
 Regular inspection of stores
 Minimizing storage time
 Emptying & cleaning feed silos at monthly interval
 Detoxification of toxins by different non nutrient agents
should be taken up
 Detoxification of Aflatoxin- Activated charcoal
 Good conditions during harvesting, transportation and
storage of feed stuffs are important in preventing of growth
of moulds

51. Incidence of Coccidiosis should be checked as it will
aggravate the heat stressed birds
 Anticoccidial drug Nicarbazine exert delirious
effect in heat stressed birds
 Administration of above drug in lower levels
along with second Coccidiostat is recommended
 Amprolium can also be used but in high levels it
may cause deficiency of thiamine
Coccidiosis

52.  During heat stress need proper care and
management
 Medicines should be administered at the
early morning when temperature is low
 Drugs should be administered with cool ,
fresh & quality feed
Drug administration

53.  All-in & All-out system of poultry
management in hot climates is most preferred
 Appropriate disinfection programme is
followed between the batches
 In high temperature there may be rapid
evaporation of disinfectant solution resulting
in less contact time
Disinfection & hygiene

54.  In India there are
zones having climate
ranging from 400F to
850F during winter
 The optimum
temperature drops
below 450F steps
must be taken to
warm the house
Winter Management

55.  Chick mortality due to lowered temperature
 Most of the energy used by the birds maintain
their body heat, thus retarding its growth
 Combs becomes cyanotic
 Birds do not reach peak production during the
expected period
 Sexual maturity is delayed in pullets and these
birds turn out to be poor layers
Adverse Effects

56.  Birds consume more feed to maintain body temperature
 More moisture is retained in winter due to less
evaporation and creates dampness in the house
 Houses must be built on an elevated ground to prevent
stagnation of water, which in turn cause severe disease
problems
 A lower environmental temperature increases oxygen
consumption, blood pressures and thyroid size

57.  Cooler temperatures are immunosuppressive
and thus predispose birds to infectious agents
endemic in that environment
 Respiratory infections like CRD, infectious
bronchitis, avian influenza and coryza etc.
compromise the lung capacity and therefore
reduce the oxygen supply through the lungs

58.  Provide clean litter material and increase the
thickness of litter
 Provide good ventilation but prevent chill air
from entering in
 Seal all the cracks and crevices in the house
 Remove all leaking waterers and repair leaky
roofs
Alleviating Measures

59.  The overhang must be 4-6 feet in length to
withstand wind and to prevent rain water from
splashing inside
 The roof height should be lowered
 Asbestos roof may be used as they hold the
warmth within the house
 Side curtains can be used during severe winds
and draft thus sealing the house from cold draft

60.  Ceiling fans may be used to move hot air from the ceiling
towards the birds
 Place plastic sheets over exhaust fans which will not be
used during cold weather
 Solar heaters can be used and the energy stored and this
can be used to warm the house
 The time period for brooding chicks in cold weather will be
extended to even 4-6 weeks
 Oil or fat can be added to feed and energy levels in the feed
can be raised to meet the higher energy need of the bird

61.  Extra vitamins and minerals have to be
supplemented
 Both vitamin C and vitamin E can be
given to increase the immune response
 The feeders should always be full
 Provide warm water to the birds
 Prevent spilling of water on the litter
 Increase the stocking density by 5%

62.  In temperature countries, environmentally controlled
poultry houses are in vogue. These houses are heated
by electricity or gas
 The blower blows in warm air and fans circulate the
warm air, all this is thermostatically controlled
 Gas pressures are checked, inlets and outlets open
uniformly to keep the birds comfortable
 Ventilation is adjusted to remove excess ammonia
and to prevent increased fuel usage

63. Thanks……