Richard Wall Flashcards
why do grass eating animals have to migrate
most of grass biomass is underground. hunter gatherers followed migrations before domestication began,
when and where did domestication begin
11000-9000 ya.
irag/iran - mesopotamia, and Indus valley.
occurred when herd sizes increased to the point where nomadism was unsustainable so settled and animals husbandary and crop production was better.
which animals were domesticated?
earliest - sheep, derived from mouflon, Ovis gmelini.
Goats - analysis of mtDNA shows domestications of goat thought to have been in middle east 10,000 ya from a handful of animals.
Cattle - 1000 years later, Auroch ancestor
which communities domesticated pigs?
pigs - dont migrate, domesticated middle east, higher quality diet and shade needed.
sedentary communities, in SE asia, china, polynesia and N Europe.
today, people with ancestry from these regions have tolerance to lactose, due to dairying tradition, and milk based pastoralism.
why are there still some nomadic communities
in sub saharan africa, north america, arctic scandinavia
pop size never reached limits of sustainability, or the environment cannot support agriculture.
how much land and water does livestock take up today?
30% of the worlds surface
70% of agricultural land
8% of human water use
world wide, what benefits do livestock bring?
- crucial food resource in the case of crop failure (insurance against hard times e.g. drought)
- Provides livelihoods for 800 million poor small-holders
- Accounts for 40% of agricultural GDP
- Allows production of food from land that would be unsuitable for crop production.
what are the expected changes in the near future
global pop exp to reach 8.1 - 10.6 billion by 2050.
Meat demand per capita is exp to increase by 13% in developing nations btw 2008–2017 and double by 2050. meat demand increases with growing affluence and education.
how is livestock efficiency measured?
how many kilos of plant material used to create1kg meat.
which are the most and least efficient livestock products?
cow and goats milk is v efficient - 1.04 kg plant material needed to male 1kg milk
sheep meat and beef least efficient, 10kg plant material needed.
current estimated for aount of grain used to feed livestock?
Globally, 600 million tonnes of grain.
400m tonnes could be eaten by humans.
6 characteristics of nomadic food production
Low inputs low outputs marginal habitats extensive vulnerable to changes in water and foraging availability. Subsistence farming
4 characteristics of extensive farming
Pasture grazed but may be housed and fed in winter
Medium inputs,
High outputs,
Commercial farmers
7 characteristics of intensive farming
High inputs, High outputs, Max cost effectiveness Housed or feedlot Easier disease control Reduces land requirements High set up costs,
describe feedlot production systems
intensive production, animals outside in a small area or permanently housed, with high quality cereal feed, 2/3 of which could be fed to humans. often heavily medicated.
