Exam 2 Flashcards
(37 cards)
What does ventilation effect?
- Growth and health
- Fuel and electricity bills
- Removes excess heat
- Removes excess moisture
- Minimize dust
- Limit buildup of CO2 & NH3
- Provide oxygen for respiration
How does ventilation affect birds?
…
Performance loss
- no weight gain
- feed conversion
- disease incidence = condemnation increase
- overall health - uniformity of flock declines
Growers affected
Increased fuel bills/costs usage
Air quality
- O2 level = 19-21%
- ammonia (NH3) level = <25 ppm
- 5 mg per cubic meter dust @ bird level
- relative humidity = 45-65%
- CO2 level = <3000 ppm
- CO level = <200 ppm
- Litter moisture = 15-35%
Relationship between litter quality and ventilation
15-35% litter moisture
Over ventilation:
- Makes litter too dry
- RH<40% = pulls moisture out of litter
- Barn becomes dusty
- Condemnations in plant due to air sacculitis
- Does not occur much during winter
Under Ventilation:
- > 45% moisture
- Pulling in too much cold air
- Ammonia levels increase
- Damaged foot pads
- Can be too cold (during winter)
- Increased bacteria levels
- Coccidiosis
Flock Super Seven
- Facility/equipment
- Feed/Water
- quality and availability
- Temperature
- zone of thermal neutrality
- Litter Quality
- quantity and moisture
- Air quality
- Sanitation
- Stress Reduction
Ammonia
Created by bacteria that breaks down manure
Damages caused by ammonia:
- Dust and disease pathogens enter windpipe, lungs, and air sacs
- Depresses appetite & bird activity
- Burns eyes causing blindness
Constant exposure to 50 ppm of ammonia can …
Reduce feed conversion by 8 points and weight by .25 lbs
Homeothermic
Produce and dissipate heat to maintain a relatively constant temperature
Internal Body Temperature
shows more variability than mammals
no absolute body temp
Two types of heat loss
Sensible heat (dry) Latent heat (wet)
Sensible heat
Dry
Heat given off by the body into the surrounding air
What happens if the air around the bird is warmer than the broiler’s surface temp?
Birds can’t dissipate heat and heat stress will occur
Latent heat
Wet
Heat given off through respiration
Moisture in lungs absorbs heat, evaporates and then is expired
Impact of surplus heat:
- decreased feed consumption
- decreased growth rate
- increased water consumption, feed conversion, & mortality
Define ventilation
exchange of air within a house
define set point
temperature setting the controller will adjust equipment in order to achieve
define static pressure
difference in air pressure between outside and inside the house
Describe static pressure
air pulled out of barn, creates a vacuum-static pressure is the measure of that vacuum
usually expressed as inches of water column (IWG)
Measured with a manometer
Manometer
a plastic tube (like a straw) that extends between inside and outside and has water in it
inches in height difference between the two sides of tube is inches of static pressure
