Transcript Artificial insemination e- learning acvtivty - Teachnet UK-home

Artificial Insemination
GCSE Module 14
Biotechnology
Lesson 11 -13
Ouch!
Lesson objectives:
• You will understand how cattle semen is
collected from genetically suitable bulls and
introduced into suitable cows.
• You will understand the advantages of artificial
insemination over natural breeding.
Artificial insemination: very simply means
taking sperm from the best male animal and
putting into the best female animal.
It is used extensively in modern farming to
produce best diary and beef cattle and in the
breeding of race horses.
Artificial insemination:
• Semen is collected from a prize bull. It is then
diluted, frozen and stored.
• It can then be inserted directly into a fertile cow or
super-ovulation + embryo transfer can be used:
• This technique involves the prize cow being given
hormones to increase ovulation. Eggs are collected.
• .An egg from the prize cow is fertilised in vitro by
sperm from a prize bull.
• An embryo is implanted into another cow.
• Surrogate cow then gives birth to calf.
Advantages and disadvantages:
• Use of proven stock quality
• Frozen semen can be transported globally and
stored for many years
• Cost effective an straw of semen is £15 while the
cost of a Holstein bull is around £10,000. A bull is
expensive to rear, relatively unproductive,
vulnerable to disease or accident and may be
infertile.
• Flexibility: high yield dairy cows can be crossed
with dairy bull semen to create more higher yield
cows.
Safety: bulls are aggressive
Main disadvantage is that the same alleles
keep appearing in the population so there is
a loss of diversity in the gene pool (many
genes are lost). So a disease could wipe out
an entire population if resistant alleles have
been lost.
Activities:
1. Produce a set of annotated diagrams explaining
how semen is collected,stored and finally inserted
into a cow during artificial insemination.
2. List the advantages of artificial selection over
natural breeding.
Use the information provided in the previous slides
as a starting point and then supplement from your
own research. Then use MSN Messenger to
discuss your list with a partner in the class. Bring
your list to the next lesson for display.
Dating game:
Use the following website: sire selector to mate an
imaginary herd of ten milk cows with the semen from
a bull or bulls of your choice.
Produce a family tree of the crosses and provide
information on projected milk yield for the likely calves
produced. You have only a limited budget of £150 to
spend and must produce the new herd with the
highest projected milk yield possible.
Remember: a cow will usually only produce 1 calf at a
time and it can be either male or female (1:1 ratio).
Lay out your family tree with projected milk yields on
an Excel spreadsheet for display next lesson.
Plenary:
Copy and answer these questions:
1. What would you do as a farmer if a calf when fully
grown into a cow failed to give the projected milk
yield?
2. What would happen to the male calves produced
during the crossings (remember 1:1ratio of males
to females would occur)?
3. What advantages does artificial insemination have
over a natural breeding programme for the farmer?
4. How could super-ovulation + embryo transfer
further improve the selection of your milk herd?