STRESS MANAGEMENT

The term “Stress” is used to describe the detrimental effects of variety of factors on the health and performance of poultry.

Birds have limited body resources for growth, reproduction, response to environmental changes and defense mechanism .

Stress

1.Environmental (Poor Ventilation, ammonia gas, Pollutants, wet liter, high light intensity)

3. Physical (Catching, Handling Transport, Injections,Ion mobilization etc.

5. Physiological (Rapid growth, high egg prod., Process of sexualMaturing, Molting etc.)

6. Social (Over crowding various age/size, Grouping)

7.Psychological (Fear, harsh care takers, abrupt changes etc.)

2. Climatic( Extreme heat / cold, humidity )

4. Nutritional (Nutrient Shortages, Feed intake Problems,Adulterated feed, Toxic)

STRESS

Heat stress Vs Cold stress

• Tropical countries – Heat stress

• Temperate countries – Cold stress

• Which one is more dangerous?

“Cold stress is more dangerous than Heat stress”

Cold stress

• Bird 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 problem and huge

economic loss.

Chick Vs Adult birds

• Chick requires 40oC during Ist and IInd week of age.

(Hypothalamus is poorly developed in chicks)

• But optimum temperature for adult birds is 19 to 24oC.

(Normal body temperature is 41 to 42oC)

Birds are Homeothermic

Body Temp. : 41 to 42°C

Regulated by Hypothalamus– act as a thermostat

Thermoregulation in Birds

Can withstand 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

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 the most imp stressor.

Birds are susceptible to high Environmental temperature due to Absence of sweat glands. Feathered body.Fatty nature. High body temperature.

Broilers than layers. Male broilers are more susceptible. Good layers in cages than layers in DLS.

Susceptibility

Heat Produced

Bird is producing heat through Metabolic processes and Muscular activity.

Thermo neutral Zone: Heat production=Heat loss

21-240C

Heat produced in the body is lost

Heat loss Divided into two main

categories Sensible heat loss

Occurs through conduction, convection & radiation.

ideal temperature for optimum poultry production is 65-75oF.

Contd.. Insensible heat loss

Occurs through panting(evaporative heat loss)

Begins when temperature reaches 80oF

Bird can increase respiration rate upto 10 times normal.

Bird also reduce heat by raising and spreading her wings

Separating herself from other birds.

Diagram of thermo neutral zone

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

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

Spreading wings

Eggshell is made up of Calcium carbonate ________________________________ ↓ ↓Calcium Carbonate (Feed) (CO2 -Respiratory tract)(Calcium hunger)

During summer – Panting occursMore amount of CO2 is excreted out resulting in respiratory alkalosis (HCO3)

Poor egg shell formation

Physiological Changes

Egg breakage

More egg breakage during summer season

Housing Management

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)0.5H & L are height and length of obstructing building.

Or not less than 10-12 meters

Contd..

Building width :- 10-12m 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.

Contd..

Wall :- Should be water proof & poor conductor of heat.

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 (3-5 ft) to protect

the birds from strong sunrays.

• Sprinklers on roof reduce temp of shed by 5-10oC.

• 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 bolwing over wet gunnies will cool the house

• 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 metres at the ridge and eaves, respectively

Natural Ventilation Curtain-sided houses rely extensively on natural air movement Located away from obstructions (Trees, buildings).

Forced VentilationAll 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.

Contd..

Evaporative cooling:- 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 & there is increase in RH. Aspen fiber and corrugated cellulose are

two materials widely used as cooling pads.

EVAPORATIVE COOLING

Fan Pad System

Fan Fogger System

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 (90 o to 95 o F)

Birds Sitting on Cold Water Birds Sitting on Cold Water PipesPipes

Feed management• 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• 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.

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.

Protein & Amino acid Requirement

Protein has high heat increment.

Diets containing lower protein levels & supplemented with limited amino acids , methionine, lysine gave better results.

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.

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.

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.

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 ProteinsImprove Immune system.Act as antioxidant.Contribute to integrity of epithelial cells.

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.

• 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.

Other Nutrients & Feed additives Heat stress can induce unfavorable

changes in indigenous bacterial microbionta.

Supplementation of probiotic lactobacillus strains may enrich diversity of micro flora in chicken.

Restore microbial balance in jejunum & caeca of chicken.

Reduce harmful effects of heat stress.

Water management • Normal ratio of water to feed intake is 2:1 but

get changed 4:1 when temperature is above 27oC.

• Birds drink 4% more water for every one degree increase in temp above 27oC.

• 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

Water requirement increase during hot periods.

6% water intake increase per degree rise in temperature from that at 20oc temperature.

25% more drinking space should be provided.

Water below body temperature will certainly aid in heat dissipation.

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

• 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 (1-2 gm/liter) in water during hot

hours.• Addition of 0.25% of salt to drinking water increases

water consumption.

Beak trimming To prevent feather picking &

Cannibalism which is more in hot climate.

Litter mgt Is most important step in broiler

management during summer. Litter should be at least 5 cm depth , &

in good condition during summer.

Miscellaneous Management

Stocking Density Stocking density should be reduced by 10% in Summer

Heat stress makes birds more susceptible to various disease conditions. Coccidiosis Mycotoxicosis

Disease Management

Most imp 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

Control of MycotoxicosisRegular inspection of storesMinimizing storage timeEmptying & cleaning feed silos at monthly

interval.Detoxification of toxins by different non

nutrient agents should be taken upDetoxification of Aflatoxin – Activated charcoal.

Good conditions during harvesting, transportation, and storage of feed stuffs are important in preventing of growth of moulds.

Coccidiosis Incidence of coccidiosis should be checked as

it will aggravate the heat stressed birdsAnticoccidial drug Nicarbazine exert

delerious 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.

Drug administration 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.

Disinfection & hygieneAll-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.

Winter Management

• In India there are zones having climate ranging from 40oF to 85oF during winter.

• The optimum temperature in a house is 65-75oF, when the temperature drops below 45oF steps must be taken to warm the house.

ADVERSE EFFECTS

• Chick mortality due to lowered temperature. • Most of the energy used by the birds maintain

their body heat, thus retarding its growth. • Combs become 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.

• 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.

• 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.

ALLEVIATING MEASURES

• 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.

• 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.

• 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 to 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.

• 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%.

– In temperate 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.