Selective breeding
Farmer Giles has a herd of cows. He has worked out how much milk each cow
makes each day. He wants improve the milk production of his herd so that they
give even more milk. He cannot decide so he takes his problem to his vet.
Look at the cows below:
Gertrude produces 9l of extra creamy
milk, but not much meat. She copes
well in hot dry conditions but not so
well in damp conditions.
Penelope has little meat but produces
12l of milk which contains lots of
vitamins and minerals. She cannot
survive in hot dry conditions
Betsy produces lots of tasty meat but
produces 8l of milk a day. She is a
hardy cow and can withstand cold and
wet weather.
Alma has lots of meat and she
produces 13l of a day. She can cope
well in temperate conditions
Selective breeding
Look at the bulls below:
Bruiser can be violent. He has lots of
muscle and cannot survive hot, dry
conditions but does very well in a
damp climate. His mother produced
15l of milk a day.
Rufus can cope well in damp
conditions. Although he produces
little meat it is very tasty.
His mother produced 8l of milk a day.
Donald has lots of meat and can
survive and can survive well in
temperate climates.
He comes from a family line of cattle
that produces lots of high quality
milk.
His mother produced 12l of milk a
day.
Boris has lots of muscle but cannot
cope with hot dry conditions. His
family line does not produce much
milk.
Selective breeding
You are to write a report to advice farmer Giles on which cows and
bulls he should use to breed from to improve the milk production on
the farm.
The farmer lives in Tetbury where the climate is moderate but there
is a lot of rain and damp conditions.
Your report will need to include the following points:
Level 5
1. Describe the environmental factors which could affect milk
production.
2. Explain which characteristics are going to be passed down to the
calves from their parents.
Level 6
1. Select the best cow and bull from the herd.
2. Donald is an endangered species – outline the steps for making a
clone of Donald.
3. Genetic engineering could be used to make Penelope’s daughters
produce protein in their milk to make Insulin for Diabetics. Outline
how this would work
Level 7
1. Explain why you have selected the cow and the bull you have
chosen for breeding.
2. Suggest potential problems with selective breeding.
3. Advise how these problems can be reduced.
4. Write 3 pros and 3 cons for genetic engineering and
Give examples