PUBH 3132 Exam 2

Economies of Scale

increase production, lower costs

Factory farms

confined spaces, specialized facilities

Most common US CAFO

Poultry

Beef CAFO

fed grain, urine/manure accumulate

Swine CAFO

slotted floors, waste drops and goes to man-made lagoons

Chicken CAFOs

confined cages, solid straw floor

Most CAFOs…

• Feed ground and formed into pellets for better digestion 

• Provided in troughs/mechanical feeding devices 

• Pesticides applied to buildings and animals 

Ammonia

created as nitrogen in urine and moves to air

Hydrogen sulfide

created as manure broken down without oxygen present

Largest thing killing cattle/swine in CAFOS

respiratory problems from poor ventilation

Nitrogen and nitrates

Comes from land waste, nitrates go into groundwater can cause blue baby syndrome (methemoglobinemia)

Eutrophication

when waste in surface waters, decreased dissolved oxygen releases phosphorus and nitrogen which supports algae growth, anaerobic process

organic arsenicals

added to feed to promote growth, transformed into inorganic arsenic in soil/waste, can leach into soil/groundwater, spread of chicken manure to antibiotic resistance

impacts on CAFO workers

respiratory irritants: ammonia, organic dust

manure pits can have hydrogen sulfide, ammonia, carbon dioxide, methane

impacts on CAFO neighbors

odors, quality of life and mental health, impacts more rural poor non-white people

working conditions and hazards in CAFOs

slips, falls, acute, respiratory, hearing loss, zoonotic disease, heat/cold, cancer

Rendering

heating animal remains in large vat, creates tallow (fat in cosmetics) and meat-and-bone meal (dried and ground in farm/pet food)

Prion diseases

distributed through rendering cycle, degenerative brain disease

in humans: older population, neuro symptoms like dementia/speech, CJD as example not linked to contaminated beef

Bovine spongiform encephalopathy (BSE/mad cow disease)

animals with dementia, loss of coordination

Variant Creutzfeldt-Jakob disease (vCJD)

human fatal degenerative neurological disease from eating contaminated beef, could be prion disease from cattle to people

Recombinant bovine growth hormone (rBGH)

Monsanto developed genetically engineered hormone in cows, increases milk production

rBGH (recombinant bovine growth hormone) health concerns

animals: udder infections and increased use of antibiotics to treat them

humans: premature reproductive development, obesity, cancer

Fish farming risks (mostly salmon)

higher levels of PCBs, dioxins, DDT in farmed vs wild-caught salmon

Environmental impacts of fish farming

eutrophication, antibiotic resistance

US safeguards on BSE

ban on imported animals from affected countries, feed ban for meat-and-bone meal given to cows/sheep from more susceptible animals

impacts of modern agriculture

uses 40% of earth’s land

Agricultural practices disrupt ecosystems, convert biomes

Irrigation uses 70% of freshwater withdraws

Pollutes fresh and marine water supplies: fertilizer runoff, CAFO waste Contributes to eutrophication and dead zones in bodies of water

Contributes to global climate change

Nitrous oxide

• Nitrates come from waste from CAFOs and intensive use of fertilizers • Bacteria in soil convert nitrates to nitrous oxide which is released to the atmosphere