intensive rearing of domestic livestock

Question 1

intensive rearing of domestic livestock (IRDL)

Answer 1

system designed to produce the maximum yield of produce (eggs, meat and milk) at the lowest possible cost

Question 2

common livestock that are reared intensively

Answer 2

cows, pigs, chickens and turkey - these animals are all consumers

Question 3

net production for consumers

Answer 3

N = I - (F + U + R)
N = net production
I = chemical energy in the ingested food
F = chemical energy in feces 
U = chemical energy in urine
R = respiratory loss

Question 4

aim of IRDL

Answer 4

• converting the smallest possible amount of food energy into the greatest quantity of animal mass
• this means there will be more energy ready to be passed on to the next trophic level

Question 5

ways to achieve IRDL

Answer 5

• minimize energy loss from domestic animals

Question 6

how can energy conversion be achieved

Answer 6

• by ensuring most of (R) goes into growth and not other activities or organisms
• this can be done by keeping animals in confined spaces

Question 7

how does practice of IRDL increase rate of energy conversion

Answer 7

1) less energy used for muscle contractions
2) environment kept in an optimum temperature to reduce heat loss
3) predators are excluded so there is no competition and loss of organisms
4) feeding is controlled so all animals receive the optimum amount and type of food for maximum growth
5) using hormones to increase growth rates
6) selective breeding of animals to produce varieties that are more efficient at converting the food they eat to body mass

Question 8

ethical issues arising from IRDL

Answer 8

1) animal welfare;
- animals are kept unnaturally, this can cause stress and aggression to the animal meaning they can harm themselves or others
- joint pain and sickness associated with lack of movement
- parts of animals removed to reduce damage associated with attempts of harming
2) use of drugs;
- overuse of antibiotics to prevent disease which can lead to antibiotic resistance from bacteria and thus treatment becomes ineffective
- other drugs may be given to treat aggression and stress, and to increase growth, which can be passed into the meat and affect human health if consumed and also alter the flavour of meat

Question 9

environmental issues arising from IRDL

Answer 9

1) use of space - it uses less land; leaving more natural habitats for other organisms
2) safety with IRDL; high density populations are more vulnerable to rapid spread of diseases and infections coming from within the livestock
- however it is easier to prevent diseases and infections introduced from the outside as the animals are isolated
3) pollution; animals grown in intensive farms produce large concentrations of waste in a small area
- this can pollute ground water and rivers
- pollution gases such as methane produced, which are dangerous and smelly
4) use of fossil fuels; in order to achieve high energy conversion, AC’s will be used in buildings that house the animals for long period of times to always maintain the optimum temperature
- they can also be used to produce food transportation machinery
- production of materials in the building
burning of fossil fuel will release amount of CO2 emitted, increasing global warming
5) reduction of genetic diversity; selective breeding is done only to produce varieties that are useful in terms of products, this means there will be loss of other beneficial genes

Question 10

economic issues arising from IRDL

Answer 10

1) it is low cost

2) quality of food may be considered inferior and lacking taste compared to foods that are produced less intensively