Chapter 1 - introduction of thermoregulation:
1. Able to describe thermoregulation within the context of agricultural science.
- Agricultural science is the field of biology that applies exact, natural, economic, and
social sciences to the practice and understanding of agriculture, including food and
fiber production, crop cultivation, animal production, and processing.
Productivity of an animals is determined by a genetic component and environmental factors
as; nutrition, health and housing. When environmental factors are suboptimal, genetic
potential cannot be fully expressed. Therefore, it is important to be aware of all that
influences environmental factors.
2. Able to describe why animal housing has both positive and negative aspects for the
animal in relation to its thermoregulation.
Animals were housed for several reasons:
1. Control of
- Growth and growth efficiency
- Production
- Reproduction
- Health and diseases
2. Manipulation of
- Behavior
- Food
- Reproduction
- lifespan
3. Conditioning of
- Climate
- Health and diseases
Animal captivation and housing can both be negative and positive.
Regarding positive aspects: supply of food, water and the shelter against extreme climate
conditions.
Regarding negative aspects: when the needs of an animal are not met, often because housing
takes away the animals choices. Additionally, environment can become more complex for
animals when housed close together, which increases infection risk, and reduces resilience.
When nutritional needs are not met deficiencies can occur.
To measure how housing influences performances, look at these characteristics:
- Behavior
- Hormone levels
- Fertility
- Health and disease resistance
- Production
- Growth
- Heat production/ dissipation
3. Understand how an animal physiologically responds to a disturbance of its homeostasis
and what the effects are of this disturbed homeostasis.
When animals are exposed to changes in their environment/ climate, they can experience this
as a stressor, which disturbs their homeostasis (body’s attempt to maintain a constant and
balanced internal environment).
Maintenance of the body involves:
- Temperature
- Osmotic value
, - Blood sugar levels
Environment changes detected by receptor information is compared with set point of the
CNS those that deviate from each other, animals will adjust their neural/endocrine system
metabolism changes, in this case homeostasis is restored by adjusting.
In rare situations an animal adapts to a change, if the stressor persists for a long time/often
reoccurs.
Adaptation to stressors:
1. Acclimation; all reactions of an animal occurring after changing 1 specific
environmental factor
2. Acclimatization; all reactions of an animal occurring after more complex changes in
climate/ housing conditions
3. Habituation; adaptation to a repeater stimulus that is initially experienced as a stressor
4. Able to describe how a disturbance of the homeostasis has an effect on energy
metabolism.
An animal requires energy for maintenance, production and reproduction, for this energy is
available through nutrients being absorbed, digested and metabolized.
In case of a stressor, the animal needs to set certain priorities relate4d to tis energy
distribution. So adaptation costs energy and reallocation of the available nutrients is
necessary, divided in maintenance and performance.
Homeothermic animal exposed to cold try to maintain body temperature increase heat
production and energy requirements towards maintenance an increase in maintenance at
the expense of energy that is available for performance.
Chapter 2 - thermoregulation and heat balance:
1. Able to describe the two classifications of thermoregulation, including the
characteristics
Classifications based on temperature regulation
1) Homeothermy: animals that are able to maintain their body temperature within
fairly narrow limits
- Independent of the ambient temperature or activity level
- Actively controlled by ANS
- Not entirely constant during the day to prevent continuous regulation
of heat production- and loss
- High activity during day; higher body temperature during day than
night (nocturnal animals the other way around)
- Slight temperature changes during seasons and stages reproductive
cycle
- Refers to core body temperature, not skin or peripheral body parts.
This is because the vital organs are located inside the body and must
have a constant temperature to optimize their functioning.
- Endotherm animals that regulate their body temperature by metabolic
activity
2) Poikilothermy: animals temperature dependent on their environment
- Temperature is influenced by ambient temperature
- Ectotherm animals regulate their temperature by changing their
behavior, so dependent on their environment
, - Sometimes also endothermic animals, such as a sloth and naked-
mole rath
2. Able to explain the meaning of heat balance and which factors contribute to the heat
balance
Homeothermia means that heat production equals heat loss, since body temperature would
otherwise increase or decrease. M = H + ∆C (metabolic heat production= heat loss +
change in body heat content)
- in homeothermic animals ∆C is zero under normal conditions.
∆C = W × ∆T × c (change in body heat content= body weight * temperature
gradient * specific heat capacity of the body determined by body composition)
Water has a specific heat capacity of 4.184 J g-1 °C-1 and a dry matter
concentration of 1.674 J g-1 °C-1 . Because a body contains, on average, 70% water,
a specific heat capacity of 3.4 to 3.5 J g-1 °C-1 is often used.
In the hypothalamus are the thermoregulatory centers located, for heat production- and loss.
Inside the hypothalamus anterior is the center for heat loss, and in the hypothalamus
posterior is the center for heat production and retention (insulation) found.
Heat production Heat loss
Basal metabolic rat Vasoconstriction/ vasodilation (narrowing
and widening blood vessels)
Feed intake Insulation (body tissue, coat)
Shivering thermogenesis ST (involuntary Sensible heat (energy transferred from a
muscle contractions) hotter object to a colder one)
Non- shivering thermogenesis NST Evaporation (verdamping, a liquid changes
( specialized brown adipose tissue through to a gas, a process that removes heat from a
metabolic processes) surface. )
Muscle activity Posture
it can be concluded that heat production is a chemical process, where heat is produced during
nutrient oxidation, whereas heat loss is a physical process. Keep in mind that heat production
can never decrease below a certain level because some essential body processes must be
maintained!
- Hypothermia: body temperature decreased
- Hyperthermia: body temperature increased
Chapter 3: heat loss
1. Able to describe which types of heat loss an animal can use.
Heat can be lost in 6 different ways:
1) Radiation (Hr)
2) Convection (Hc) Sensible heat loss (Hs)
3) Conduction (Hd)
4) Skin evaporation Evaporative or latent heat loss
5) Respiratory evaporation (He)
6) Heating of food and water
1. Able to describe thermoregulation within the context of agricultural science.
- Agricultural science is the field of biology that applies exact, natural, economic, and
social sciences to the practice and understanding of agriculture, including food and
fiber production, crop cultivation, animal production, and processing.
Productivity of an animals is determined by a genetic component and environmental factors
as; nutrition, health and housing. When environmental factors are suboptimal, genetic
potential cannot be fully expressed. Therefore, it is important to be aware of all that
influences environmental factors.
2. Able to describe why animal housing has both positive and negative aspects for the
animal in relation to its thermoregulation.
Animals were housed for several reasons:
1. Control of
- Growth and growth efficiency
- Production
- Reproduction
- Health and diseases
2. Manipulation of
- Behavior
- Food
- Reproduction
- lifespan
3. Conditioning of
- Climate
- Health and diseases
Animal captivation and housing can both be negative and positive.
Regarding positive aspects: supply of food, water and the shelter against extreme climate
conditions.
Regarding negative aspects: when the needs of an animal are not met, often because housing
takes away the animals choices. Additionally, environment can become more complex for
animals when housed close together, which increases infection risk, and reduces resilience.
When nutritional needs are not met deficiencies can occur.
To measure how housing influences performances, look at these characteristics:
- Behavior
- Hormone levels
- Fertility
- Health and disease resistance
- Production
- Growth
- Heat production/ dissipation
3. Understand how an animal physiologically responds to a disturbance of its homeostasis
and what the effects are of this disturbed homeostasis.
When animals are exposed to changes in their environment/ climate, they can experience this
as a stressor, which disturbs their homeostasis (body’s attempt to maintain a constant and
balanced internal environment).
Maintenance of the body involves:
- Temperature
- Osmotic value
, - Blood sugar levels
Environment changes detected by receptor information is compared with set point of the
CNS those that deviate from each other, animals will adjust their neural/endocrine system
metabolism changes, in this case homeostasis is restored by adjusting.
In rare situations an animal adapts to a change, if the stressor persists for a long time/often
reoccurs.
Adaptation to stressors:
1. Acclimation; all reactions of an animal occurring after changing 1 specific
environmental factor
2. Acclimatization; all reactions of an animal occurring after more complex changes in
climate/ housing conditions
3. Habituation; adaptation to a repeater stimulus that is initially experienced as a stressor
4. Able to describe how a disturbance of the homeostasis has an effect on energy
metabolism.
An animal requires energy for maintenance, production and reproduction, for this energy is
available through nutrients being absorbed, digested and metabolized.
In case of a stressor, the animal needs to set certain priorities relate4d to tis energy
distribution. So adaptation costs energy and reallocation of the available nutrients is
necessary, divided in maintenance and performance.
Homeothermic animal exposed to cold try to maintain body temperature increase heat
production and energy requirements towards maintenance an increase in maintenance at
the expense of energy that is available for performance.
Chapter 2 - thermoregulation and heat balance:
1. Able to describe the two classifications of thermoregulation, including the
characteristics
Classifications based on temperature regulation
1) Homeothermy: animals that are able to maintain their body temperature within
fairly narrow limits
- Independent of the ambient temperature or activity level
- Actively controlled by ANS
- Not entirely constant during the day to prevent continuous regulation
of heat production- and loss
- High activity during day; higher body temperature during day than
night (nocturnal animals the other way around)
- Slight temperature changes during seasons and stages reproductive
cycle
- Refers to core body temperature, not skin or peripheral body parts.
This is because the vital organs are located inside the body and must
have a constant temperature to optimize their functioning.
- Endotherm animals that regulate their body temperature by metabolic
activity
2) Poikilothermy: animals temperature dependent on their environment
- Temperature is influenced by ambient temperature
- Ectotherm animals regulate their temperature by changing their
behavior, so dependent on their environment
, - Sometimes also endothermic animals, such as a sloth and naked-
mole rath
2. Able to explain the meaning of heat balance and which factors contribute to the heat
balance
Homeothermia means that heat production equals heat loss, since body temperature would
otherwise increase or decrease. M = H + ∆C (metabolic heat production= heat loss +
change in body heat content)
- in homeothermic animals ∆C is zero under normal conditions.
∆C = W × ∆T × c (change in body heat content= body weight * temperature
gradient * specific heat capacity of the body determined by body composition)
Water has a specific heat capacity of 4.184 J g-1 °C-1 and a dry matter
concentration of 1.674 J g-1 °C-1 . Because a body contains, on average, 70% water,
a specific heat capacity of 3.4 to 3.5 J g-1 °C-1 is often used.
In the hypothalamus are the thermoregulatory centers located, for heat production- and loss.
Inside the hypothalamus anterior is the center for heat loss, and in the hypothalamus
posterior is the center for heat production and retention (insulation) found.
Heat production Heat loss
Basal metabolic rat Vasoconstriction/ vasodilation (narrowing
and widening blood vessels)
Feed intake Insulation (body tissue, coat)
Shivering thermogenesis ST (involuntary Sensible heat (energy transferred from a
muscle contractions) hotter object to a colder one)
Non- shivering thermogenesis NST Evaporation (verdamping, a liquid changes
( specialized brown adipose tissue through to a gas, a process that removes heat from a
metabolic processes) surface. )
Muscle activity Posture
it can be concluded that heat production is a chemical process, where heat is produced during
nutrient oxidation, whereas heat loss is a physical process. Keep in mind that heat production
can never decrease below a certain level because some essential body processes must be
maintained!
- Hypothermia: body temperature decreased
- Hyperthermia: body temperature increased
Chapter 3: heat loss
1. Able to describe which types of heat loss an animal can use.
Heat can be lost in 6 different ways:
1) Radiation (Hr)
2) Convection (Hc) Sensible heat loss (Hs)
3) Conduction (Hd)
4) Skin evaporation Evaporative or latent heat loss
5) Respiratory evaporation (He)
6) Heating of food and water
