1

2

Why do we need Poultry Housing?

Chickens being warm blooded can maintain internal body temperature (homeostasis).

Since modern genetically evolved birds have a very fast growth rate and increased egg production, they also need modern housing as they cannot adjust well to extremities.

3

4

Controlling Body temperature The internal body temperature of birds varies than

mammals so there is no absolute body temperature in birds.

The body temperature of adult chicken is between 105OF to 107OF or 40.6oC to 40.7oC

Body temperature of newly hatched chick is about 103OF(39.7oC ) and increases daily until it reaches a stable level at 3 weeks of age.

5

Continued

Smaller breeds have higher body temperature.

Male chickens have slightly higher body temperatures than females, due to higher muscle mass and metabolic rate.

Activity increases the body temperature birds on floor have a higher body temperature as compared to birds in cages.

6

Continued

Molting birds have a higher body temperature than feathered birds

When feed enters the digestive tract birds body temperature also increases

Broody hens have a higher body temperature than non-broody hens.

7

8

Continued Body temperature increases with increasing

light intensity.

There is a tendency for the core body temperature to rise as the temperature goes above or below the thermo neutral zone that is (65-75OF/18-24oC)

9

Heat Losses from the body Heat is lost by the bird by the following

methods:

Sensible heat Radiation Conduction Convection Fecal excretion Egg Production Latent Heat

10

Lethal Body temperature When the heat produced by the birds is greater

than the heat lost then the core body temperature of the bird will rise beyond it’s with stand capability and it will die of heat prostration.

Upper lethal temperature is: 116.8OF/ 47oC

11

Mechanism Principle Heat is lost through the skin in chickens.

When the outside temperature increases the blood vessels of the skin dilate to increase heat loss and when the outside temperature decreases the blood vessels constrict to minimize heat loss.

12

Mechanisms to maintain body temperature

Panting: when heat cannot be dissipated by radiation, convection and conduction then the birds adopt the way of panting.

This brings the outside air in contact with the membranes of the respiratory system. Heat is lost by the water vapor lost as hot air removes the moisture from the membranes.

13

14

Continued..

Continuous panting causes dehydration and birds drink excess of water. The surplus is excreted in droppings.

Panting will start at 29.4OC at 50% humidity

High temperatures and high humidity can be lethal for the birds. As the ambient temperature is high it will pant but due to high humidity adequate moisture is not lost as a result the body temperature will rise and death may occur.

Proper ventilation must be done to ensure the comfort of the bird.

15

Continued.. As temperature increases feed consumption decreases

and as temperature decreases feed consumption increases. In season of high temperatures proper and maximum ventilation should be done to ensure good feed intake.

As temperature rises bird activity also decreases as birds rest to minimize heat production. Similarly when temperature lowers, activity increases to ensure heat production.

16

Heat Gain and Loss in Poultry house

Good poultry housing is designed to alleviate extremes in environmental conditions and thus to ensure that birds are comfortable and productive.

Heat is measured in British Thermal Units(btu). One btu is the amount of heat required to raise the temperature of 1lb of water by 1OF at 59OF.(1lb = 0.45kg)

To ensure proper housing all the aspects of heat gain and loss must be ensured through proper ventilation and the selection of proper materials.

17

Water Production and Loss The amount of water consumed depends on

body weight bird type salt levels in the diet ambient temperature relative humidity(RH)

Water is lost by the bird through panting and in case of laying hens through eggs.

18

Continued..

At 21oC/70o F and 60% RH the amount lost through respiration equals the amount lost through fecal excretion for a 1.8kg bird.

At 21oC/70o F birds will consume twice the water as compared to feed.

As the age of the bird increases so does the moisture content in the fecal.

19

Environment

Poultry house should be designed in a place where both the outside as well as the inside environment are conducive to the well being of the staff and the flock.

Generally the considerations should be:1. Isolate places for good bio security: not to isolated.2. Near a village3. Away from heavy industrial setup4. Basic infrastructure facilities should be there.5. Distant from nearby poultry farms.

20

21

Summary Body temperature of adult chicken is between 105OF

to 107OF Body temperature of newly DOC is about 103OF Panting is used to maintain the body temperature

when bird cannot dissipate heat through conduction, convention and radiation

Water is lost by the bird through panting and in case of laying hens through eggs

Proper environment and ventilation should be provided to the bird to ensure its comfort.

22

23