Environmental Physiology and Animal Health Flashcards
Poikilotherms
cold-blooded animals
Homeotherms
warm-blooded animals
What is intensive management?
Intensive management is a style of management where the environment is highly controlled and regulated. It is good for research because it removed many variables.
ex. large swine and dairy facilities, Penn State Labs, etc.
What is extensive management?
Extensive management is a style where the producer has less control over the environment, and the animals adapt to fit the environment.
What is the temp. regulation equation?
(excess) heat produced by animal + (additional) heat absorbed by animal = heat loss
Conduction
exchange of heat between objects that are touching
Convection
transfer of heat by air movement
Radiation
exchange of heat between objects that are not touching
Evaporation
heat lost from skin and respiratory tract
Heat loss > heat gained =
hypothermia
Heat loss < heat gained =
fever
What is the TNZ?
The TNZ is the thermoneutral zone, aka the comfort zone.
It is the range of ambient temperatures in which an animal can maintain thermal balance by physical means of heat transfer, where heat production and heat loss are about the same.
Animals are most effective and produce the best when they are in their respective TNZ.
It is where the greatest difference between energy required and maintenance required is on the effective temp. chart.
What affects the TNZ?
Age and species
What are the LCT and UCT
Lower critical temp. and upper critical temp.
These two shift together and represent where heat or cold stress occurs.
How do animals adapt to temps less than their TNZ (cold stress)?
- animals increase food intake, and the hormone thyroxin (targets regular body tissues), produced by the thyroid gland, increases the metabolic rate
- reduce blood flow to extremities
- shiver hunch
- huddle together
- increase body insulation (fat, hair, etc.)
What ways are their to help control cold stress?
Provide windbreaks for animals (natural ones include trees and shrubs, some man made ones include fences, wooden partitions, etc.)
Ensure the animal stays dry.
How do animals adapt to temps higher than their TNZ (heat stress)?
- water consumption increases
- respiration increases
- perspiration increases
- blood vessels dilate
- animal increases their surface area
- decrease body insulation
- less activity
- lower feed intake
What ways are there to help control heat stress?
Shade
Evaporative cooling (ex. sprinkler and fan, and example of convection and evaporation)
Refrigerative cooling (AC)
Ensure available of clean water
What are some other ways to help reduce animal stress due to the environment?
- effective ambient temp. (temp. adjusted for wind, precipitation, dampness, etc.)
- ration adjustments
What ration adjustments are made for cold stress?
Decrease the protein percent in the feed due to the animal’s higher intake of food.
What ration adjustments are made for heat stress?
Increase the density of protein percent in the feed ration and increase electrolytic minerals (like sodium and potassium).
What factors affect the critical temperatures (LCT and UCT)?
hair, coat, fat reserves, age, weight
Describe other stresses that affect animals.
Hypoxia (insufficient oxygen supply, can lead to hypertension and Brisket Disease in cattle)
noise
introduction of new animals
overcrowding
presence of predators
What is Brisket disease?
A disease in cattle resulting from hypoxia, which causes hypertension. Fluid builds up in the brisket, which is located near the heart and lungs.
Define disease
any deviation from a normal state of health
Define contagious disease
infectious disease; a disease that is transmitted from one animal to another