Climatic Change and Chicken Immunity
503
The latent heat then warms the surrounding air around the new cloud droplet causing instability. This increases the cloud height and depending on how unstable the
atmosphere is, thunderstorms could form from these growing clouds. Thunderstorms
release enormous amounts of latent heat which add to the instability in the atmosphere causing some thunderstorms to become severe. In hurricanes, latent heat is
released within the clouds of the hurricane, warming the air inside the clouds. The
storm will then intensify, or gain strength [14, 15].
3.2 Sensible Heat
Sensible heat is the energy required to change the temperature of a substance. The
temperature change can come from the absorption of sunlight by the soil or the air
itself. Energy moves through the atmosphere using both latent and sensible heat
acting on the atmosphere to drive the movement of air molecules which create wind
and vertical motions [16].
How Does This Relate to Chicken?
Evaporation of panting in chickens leads to cooling of the body surface on hot
days. Evaporation is more effective when there is some wind to carry the moisture
away. However, in really hot conditions the body may shut down and stop panting.
This is particularly true in areas of bright sunlight, which will increase their body
temperature due to the sensible heat released by absorbing the solar radiation. In that
case, the body’s temperature can rise very quickly and cause hyperthermia or heat
stroke, which can lead to death [17].
4 Climate Change and Chicken Production
Chicken flocks are particularly vulnerable to climate change because birds can only
tolerate narrow temperature ranges [18]. Regarding productivity, housing systems
need to be managed to maintain optimal seasonal temperatures and reduce the
embargo of heat stress, and increased investment will be required in ventilation
and cooling [19]. Costs are likely to increase as the result of the need to cool buildings especially in summer and reduce house humidity [14]. Building infrastructure
and maintenance will have to cope with more intense weather events and increased
rainfall. Stocking density in the house may need to be reduced in extremely high temperatures, and actively controlled ventilation could become essential in transportation
vehicles [20].
503
The latent heat then warms the surrounding air around the new cloud droplet causing instability. This increases the cloud height and depending on how unstable the
atmosphere is, thunderstorms could form from these growing clouds. Thunderstorms
release enormous amounts of latent heat which add to the instability in the atmosphere causing some thunderstorms to become severe. In hurricanes, latent heat is
released within the clouds of the hurricane, warming the air inside the clouds. The
storm will then intensify, or gain strength [14, 15].
3.2 Sensible Heat
Sensible heat is the energy required to change the temperature of a substance. The
temperature change can come from the absorption of sunlight by the soil or the air
itself. Energy moves through the atmosphere using both latent and sensible heat
acting on the atmosphere to drive the movement of air molecules which create wind
and vertical motions [16].
How Does This Relate to Chicken?
Evaporation of panting in chickens leads to cooling of the body surface on hot
days. Evaporation is more effective when there is some wind to carry the moisture
away. However, in really hot conditions the body may shut down and stop panting.
This is particularly true in areas of bright sunlight, which will increase their body
temperature due to the sensible heat released by absorbing the solar radiation. In that
case, the body’s temperature can rise very quickly and cause hyperthermia or heat
stroke, which can lead to death [17].
4 Climate Change and Chicken Production
Chicken flocks are particularly vulnerable to climate change because birds can only
tolerate narrow temperature ranges [18]. Regarding productivity, housing systems
need to be managed to maintain optimal seasonal temperatures and reduce the
embargo of heat stress, and increased investment will be required in ventilation
and cooling [19]. Costs are likely to increase as the result of the need to cool buildings especially in summer and reduce house humidity [14]. Building infrastructure
and maintenance will have to cope with more intense weather events and increased
rainfall. Stocking density in the house may need to be reduced in extremely high temperatures, and actively controlled ventilation could become essential in transportation
vehicles [20].