Investigation of barn microclimate

Question 1

Microclimate

Answer 1

A relatively small local area, a defined zone where the climatic conditions are different than the in surrounding environment

Question 2

Major environmental factors affecting animals

Answer 2

• Ambient Temperature
• Relative Humidity, Moisture Loss
• Solar and Thermal Radiation
• Air Velocity, Quality
• Light
• Noise

Question 3

Thermal Environment of Animals

Answer 3

• temperature: major environmental factor–> affects bio-functions
• body temp primarily depends on balance of heat prod and loss
• tissues: poor heat conductors
• blood: main heat transfer
• different thermoregulation strategies in animals: poikilothermy vs homeothermiy

Question 4

Feedback control mechanisms for thermoregulation in homeothermic animals

Answer 4

• Physiological changes:
◦ Thermo-sensitive receptors in CNS, skin and some internal organs
◦ Central and peripheral information–>hypothalamus (set point)
‣ Hypothalamus regulates heat-losing or -conserving mechanisms
• in hot: vasodilation, sweating, panting
• in cool: vasocontstriction, piloerection, shivering/
nonshivering thermogenesis

Question 5

Adaptation to changes of environment conditions

Answer 5

• successful adaptation is equal with surviving (biological view)
• zoo-technical point of view: successful adaptation, if the productivity in the changed environment is not different significantly from the productivity shown in optimal conditions
• adaptation: short or long term, specific or non-specific
  1, phase 1: fast balancing (CNS controls heat loss and conservation)
  2, phase 2: metabolic changes
  3, phase 3: morphological changes

Question 6

Feedback short-term (immediate) control mechanisms for thermoregulation in homoeothermic animals

Answer 6

• Behavioral changes:
◦ Changing the body position
◦ In warm, moving activity declained
◦ Seeking shade
◦ Water demand is increasing, seeking water
◦ Dabble (if the body surface is getting wet, the heat production may decrease by 8 to 14%)
◦ Avoiding direct sun radiation

Question 7

Mid-therm adoptation mechanisms

Answer 7

• In the stage 2:
◦ Reducing appetite, decreasing metabolic rate *Humans can dissipate about 190% of their metabolic heat
production by evaporation, the cattle only 105%

• Two different strategies:
◦ Group 1: poultry (insulation by feather) and swine (poor sweating, thick insulation), maintains a constant body temperature primarily by regulating metabolism.
◦ Group 2: horses (intensive sweating) and ruminants (sweat glands exist, but primarily by respiration), maintains body temperature primarily by Regulating heat loss

Question 8

Examples on long term adaptation

Answer 8

• When the climatic change induces morphological changes (for example structure of hair, body condition etc.)

Question 9

The interrelationships between homeotherm animals and their microclimatic-environment

Answer 9

• Continuous endeavor for optimal body temp for maintenance the physiological functions with the minimum investmentment of energy – THERMONEUTRAL ZONE
• The animals can compensate the suboptimal conditions in a range, but in such cases plus energy investment is needed–COMPENSATION ZONE
• Overwhelmed thermoregulation, when temp is over on the chance of compensation–RISKZONE

Question 10

The flow of energy in the animals

Answer 10

• The total energy intake utilized by the body for:
◦ Components of waste materials (feces, gases and urine)
◦ Maintenance of life functions
‣ Body temp control
‣ Movement
‣ Renewing cells, tissues, etc.
◦ Animal production

Question 11

Flow of energy through the animals

Answer 11

• The Metabolizable Energy provide the basis of the animal production
◦ ME=Energy Intake – En (Faece) – En (Urine)
• ME is utilized partly for maintenance and the energy requests of moving and thermal control mechanisms also reduce the available energy for production.
• The efficiency of production is equal with the proportion of total ME what is used up for the production

Question 12

Species differences in critical ambient air temp tolerance

Answer 12

• Animals living in hot or cold climates must undergo some functional adjustments to maintain their normal thermal balance.
◦ Rate of metabolism
◦ Respiration
◦ Bloodcirculation
◦ Fluid and electrolyte transport
◦ Skin thickness
• The diversity of animals in size and structure is reflected in some variations in homeostatic mechanisms.