environment

Question 1

environmental stressors

Answer 1

uncontrollable envir factors cause stress in animals

• weather (e.g. heat, humidity, & cold)
• can inhibit ability of animal to grow, lactate, breed, & can cause an increase in the incidence of disease

Question 2

livestock impacts on envir

Answer 2

• air & water quality, overgrazing, & damage to riparian areas
• greenhouse effect: radiant energy is captured & absorbed by greenhouse gases ➔ transfers heat to other parts of atm & radiates heat in many directions & back into earth’s surface
  
  1. methane (CH4) from enteric fermentation in ruminants
  2. nitrous oxide (N2O) from microbial denitrification in manure & fermentation
  3. carbon dioxide (CO2) from respiration
• concerning to envir & human health:
  
  • ammonia = harmful to worker health
  • hydrogen sulfide
  • particulate matter (dust)
  • volatile organic compounds (e.g. methanol & ethanol) = precursors to smog & ozone
  • airborne bacteria
• Clean Air Act regulations enforce ↓ of large quantities of air pollutants
• from facilities:
  
  • nutrients (primarily N & P)
  • organic matter
  • solids
  • pathogens
  • volatile compounds
• livestock contribution to climate change ↓ to 4%

Question 3

greenhouse gases

Answer 3

1. methane (CH4) from enteric fermentation in ruminants
2. nitrous oxide (N2O) from microbial denitrification in manure & fermentation
3. carbon dioxide (CO2) from respiration

Question 4

livestock produnction of methane comes from

Answer 4

enteric fermentation in ruminants

Question 5

livestock produnction of nitrous oxide comes from

Answer 5

microbial denitrification in manure & fermentation

Question 6

livestock production of CO2 comes from

Answer 6

respiration

Question 7

ways to monitor envir impacts on livestock

Answer 7

• body temp = most common
  
  • “instantaneous reading” thermometers
  • telemetry systems relay info from a free ranging animal to a receiver located at a remote site
  • cutaneous (skin) evaporative cooling (e.g. licking, wallowing)
• respiratory system
  
  • body heat lost by evaporative cooling through resp system or skin
  • animals with a low capacity for sweating normally have a high capacity for panting and vice versa

Question 8

biogenic carbon cycle

Answer 8

• atm CO2 ➔ carbs in plants ➔ cow’s rumen ➔ converted to methane & released ➔ converted to atm CO2 through hydroxyl oxidation ➔ carbs in plants
• cyclic
• no additional CO2 as long as herd size decreases or stays same

Question 9

fossil fuels

Answer 9

ancient forests & animals fossilized & stored in the ground

• e.g. oil, coal, gas
• humans are excavating & burning them releasing new CO2 into atm
• not a cycle

Question 10

ammonia

Answer 10

• serious economic & social problem: human & animal health hazard
  
  • airway obstruction
  • inflammation
  • decreased pulmonary fx
• contributes to odor problems
• considered an ecological & environmental pollutant.
• major source from mixture of urea (present in urine), urease (present in feces and soil—manure protein), bacteria, & organic nitrogen

Question 11

locations for housing dairy cattle at UC Davis

Answer 11

1. calf hutch
2. pen 10: small heifer pen = growing heifers with high protein requirement
3. pen 13: breeding pen = less of a protein requirement
4. waiting/washing parlor in milking area
5. close-up pen (trial barn) = low protein requirements compared to lactating cows
6. high lactating cows = highest protein requirement