Housing, Environment & Animal Health

Why do we house animals?

• Predators

• Biosecurity

• Control of diet

• Parasite control

• Ease of management

• Control of the environment

• Rest pasture/In the west of the UK, poaching

• Increase output from pasture

Productivity! (or social)

What are the requirements of a housing system?

• Contain stock

• Provide shelter

• Provide a dry comfortable lying + loafing area

• Provide suitable nutrition

• Remove excess moisture

• Remove noxious gases

• Maintain appropriate temperature ranges

• Separate animals from faecal matter/urine

• Manage the pathogen load

• Provide a safe working environment

What might be some extra housing accomodations?

Milking facilities

Handling facilities

Separation facilities:

• For males

• For ill animals

• For birthing animals

• Age/management groups

What are some common problems attributable to housing deficiencies?

• Disease

• Injury

• Inappropriate welfare

• Sub-optimal production

• Death

• Increased costs/lower efficiency

What often goes wrong with housing procedures?

• Management

• Building design

• Building location

• Breakages

• Changes in:

• Stocking density

• Stock type

• Management

What is the thermo-neutral zone?

• What are the LCT and UCT?

Thermo-Neutral Zone (TNZ)

• Definition: The range where an organism can maintain a stable core temperature without significant changes in metabolic heat production or evaporative cooling.

• Metabolic Rate: Resting metabolic rate is minimal and constant within this zone.

• Regulation: Achieved by adjusting sensible (dry) heat loss via skin blood flow. 

Lower Critical Temperature (LCT) 

• Below TNZ: The ambient temperature drops below the LCT.

• Response: The body increases heat production (shivering, non-shivering thermogenesis) to offset increased heat loss. 

Upper Critical Temperature (UCT)

• Above TNZ: The ambient temperature rises above the UCT.

• Response: The body increases evaporative cooling (sweating, panting) to dissipate excess heat. 

What are the main environmental factors impacting on thermo-neutral and comfort temperatures?

• Airspeed/convection

• Air temperature

• Moisture content of atmosphere

• Conduction

• Radiation

What animal factors impact thermo-neutral and comfort zone temperatures?

• Coat length, type and whether wet or dry

• Metabolic work

• Size (surface area/ body mass)

What is effective ambient temperature?

Effective ambient temperature - Effective ambient temperature is the actual temperature of the surrounding air or environment

- index of heating or cooling power of the environment, which includes solar radiation, wind, humidity, precipitation. There are several, including wind chill index and temperature humidity index. No index covers all conditions

What does absolute humidity mean?

1. Absolute Humidity. This is a measure of the actual amount of water vapour present in a given quantity the air (g/m').

What does relative humidity mean?

2. Relative Humidity. (Simplified Definition) This is a measure of the amount of water vapour present in the air, expressed as a percentage of the maximum amount of water which the air is capable of holding, when it is saturated at that particular air temperature

How does absolute humidity change with each 10C rise in temperature?

• Absolute humidity remains constant regardless of temperature changes. Relative humidity varies inversely with temperature: if air warms, RH drops; if it cools, RH rises.

What happens when temperature changes? 🔽 When temperature decreases

• The air’s capacity to hold water drops

• But the actual amount of water vapor stays the same (initially)

• So the air becomes more “full”

👉 RH increases

---

🔼 When temperature increases

• The air can now hold more water vapor

• But the actual water amount hasn’t changed

• So the air is less “full”

👉 RH decreases

If RH is at 100% it feels _______.

If RH is at 0% it feels ______.

warmer

colder

• Humidity affects thermal comfort, it also affects how we can manage the environment.

• Generally pathogens survive less well at low RH

Why is moisture bad and how can it be managed?

• Generally moisture is bad -pathogens survive

• Relies on air flow to remove

• Aided by the temperature 'lift' in the building

• The amount of moisture is affected by the stocking rate, diet and how faeces and urine are managed

• Ingress of rainfall

Why is it important to control humidity in livestock buildings?

Important in cold environments particularly to:

• Prevent condensation on internal surfaces and consequent deterioration of materials,

• Enable bedding, flooring to dry out,

• Reduce pathogen load

• Prevent animals coats becoming wet, which increases heat loss,

• Provide a more pleasant environment for stock and workers

How are feces and urine controlled?

• Deep bedded -straw/paper/woodchip

• Slats

• Cubicles

• Scrapers/vacuums

• Slopes