Part I – Chapter 1
Poultry body temperature is more variable than mammals, and there is no absolute temperature in their case.
* Reasons for this diversity:
• The temperature of the hatched chick is 39.7°C and it increases daily and reaches the constant level of an adult bird at the age of three weeks.
• The body temperature of small breeds of poultry is higher than the body temperature of large breeds.
• The body temperature of the rooster is relatively higher than that of the chicken, and the reason for that is more muscle and metabolic activity.
• Activity increases the body temperature, that’s why the temperature of the bird in the bedding system is higher than the bird in the cage.
• Poultry during the molting period have a higher body temperature than feathered poultry.
• The body temperature of cramp chickens is lower than that of non cramp chickens due to low muscle and metabolic activity.
• After food enters the digestive system, body temperature rises.
• When the light intensity is high, the body temperature of the bird rises.
• When the temperature of the environment increases, the temperature of the poultry’s body also tends to increase.
Part I – Chapter 2
* Factors of body heat loss:
1. Radiation: when the temperature of the bird’s body surface is higher than the environment, the body temperature decreases through radiation. Growth dynamics
2. Transmission: This method happens very rarely because the air is a poor heat conductor, whether with high or low humidity.
3. Diffusion: When the cool air comes in contact with the surface of the bird’s body, it heats up, the warm air expands, and due to the rising of the warm air, heat is released.
4. Evaporation of water: In most mammals, moisture is removed by sweat glands, but in poultry, due to the lack of sweat glands, this process is done through the evaporation of moisture from the respiratory system.
5. Defecation
6. Egg production: The amount of heat output is negligible.
Part I – Chapter 3
* Deadly temperature
When the temperature of the bird’s body rises and is not eliminated and reaches a certain point, the bird dies due to heat stroke, which is known as the lethal temperature and is around 47 degrees, but this number is not absolute.
Part I – Chapter 4
Body temperature regulation mechanism
1. At a temperature of 21°C, about 75% of the total heat produced by radiation, transmission and diffusion methods is rejected, but this ratio is influenced by the ambient temperature (sensible heat rejection).
2. The ability of poultry to dissipate heat is more affected by the temperature of the surface of the skin than the internal temperature of the body.
3. As the temperature of the environment decreases, the capillaries of the skin contract and the blood flow decreases, and as a result, heat removal from the body decreases.
4. With an increase in the temperature of the environment, the capillaries of the skin expand and the blood flow increases and the heat removal from the body decreases.
5. If the transmission, radiation and diffusion mechanisms are not able to remove heat, the panting mechanism works.
6. In the mechanism of panting, the bird loses more moisture from the body and is forced to drink more water, and the excess water is removed by feces.
7. The higher the relative humidity, the faster the breathing.
8. As much as the ambient temperature and relative humidity are high, the bird will not be able to breathe fast enough to expel heat from the body.
9. As the temperature of the environment increases, the body temperature increases, and as a result, food consumption decreases, due to maintaining the natural body heat, which causes a decrease in growth and egg production.
10. The activity of the bird depends on the temperature change of the environment. The warmer the air temperature, the less movement and more rest, the less food and mating and the bird sits instead of standing and walking, in this case, a lot of feathers fall.
First part – Chapter 5
Production of sensible and insensible heat:
1. Expulsion of sensible heat: heat that increases the temperature of the environment as a result of the poultry’s muscle and metabolic activity due to food consumption and ultimately causes the temperature of the hall to rise.
2. Insensible heat removal: heat that is removed from the body through exhalation moisture, but does not increase the temperature of the hall.
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This post is written by Faridttt