Exam 2 Flashcards
(135 cards)
Adaptation
long term changes in animals in response to their environment that are genetically based (long change)
Acclimation
the process or result of becoming accustomed to a new climate or to new conditions (short change)
Critical temperature
the temperature below (lower critical temperature) which the animal must make physiological adjustments to maintain its body temperature. Upper critical temperature is that temperature at which the animal makes adjustments to try and cool its body.
Effective Temperature
the total heating and cooling power of the environment
Evaporation
loss of heat through vaporization of moisture from the respiratory tract and skin
Homeotherm
animals that maintain a relatively constant body temperature regardless of external temperatures
Farm Animal temps: Horses, cattle, goats, sheep, swine, chickens
Horse: 100
Cattle: 101.5
Goats & Sheep: 102
Swine: 102.5
Chickens: 107
Radiation
the exchange of heat between two objects that are not touching. Can result in loss or gain of heat.
Thermoneutral Zone
range of temperatures where heat loss and heat production are about the same. Animal is in comfort zone- no physiological response to temperature
Factors affecting critical temperature
Haircoat, subcutaneous fat, nutritional level, animal wet or dry
Thyroxine
produced by the thyroid gland, thyroxine secretion increases during cold stress and decreases during heat stress
Corticoids
produced by the adrenal gland, cortical secretions increased during cold sorters and decreased during heat stress
How do summer months affect livestock?
summer months are typically more limiting to livestock production because most of the farm animals are not well adapted to dissipating heat. Rate of gain decreases. Exception- Brahman
Shade
the cheapest and simplest method of reducing heat stress due to solar radiation, can reduce radiant heat gain up to 50%
Evaporative Cooling
one of the most effective ways to control heat stress, particularly in swine. include sprinklers, foggers, and wallows. Popular in poultry houses.
Refrigeration
refrigerated air conditioning is prohibitive in terms of cost. Can cool air down to the mid 60’s
Zone Cooling
blowing air onto the head has been effective in sows in farrowing houses
Why is Ventilation important?
need proper air movement in enclosed, confinement buildings. Moisture must be removed from the air along with ammonia. Also important for temperature control. Prevents pneumonia issues.
Why are wind breaks and shelters important?
reduce the effects of wind chill, block cold northerly wind
What are the ration adjustments during temperature stress?
increases in energy required to maintain body temperature result in decreased feed efficiency. Feed and water needs change during stress. Water intake during heavy stress increased 50- 100%
What contributes to heat stress?
high fiber diets, feed higher fiber diets during cold stress
How does light affect animal performance?
day length is associated with reproductive performance in a number of species. Also associated with hair growth.
What is one of the major problems livestock producers face today?
management of waste
methane production
fiber re-feeding
Healthy
free of disease