IGCSE BIOLOGY 0610/43/O/N/20 Q6
6.In many parts of the world dairy cattle are kept in large barns and reared intensively , as shown in Fig 6.1.
(a)Food for cattle that are reared intensively includes cereals , such as maize and barley . Ecologists have calculated that it is more energy efficient to grow crops for human consumption than food for livestock . Explain why intensive rearing of livestock is not efficient use of crops .
(b) The urine and faeces from cattle kept in barns is removed and treated in the same way as human sewage to avoid polluting the aquatic environment.
Outline the effects of untreated waste from cattle on the aquatic environment.
(c) Intensive livestock production could be one way of preventing famine.
Describe the causes of famine.