Questions on producing embryos for transplanting

Which hormone would be used to increase the number of follicles that develop?
Which hormone would increase the number of follicles that ovulate?
The donor animal may be treated with hormones to mainly to
stimulate the production of follicles
 stimulate ovulation
 ensure the animal is at the correct stage of the oestrus cycle for transplanting the embryos

Questions on synchronising breeding behaviour

Progesterone stops ovulation by
acting directly on the ovary
 inhibiting the production LH
 inhibiting FSH
 destroying the primary follicles

Questions on increasing milk production

Where in the body is the pituitary gland?
the ovaries
 the neck
 just above the kidneys
 the brain

The DNA in the genetically engineered bacterium will be;

entirely cattle DNA
 recombinant DNA
 have RNA incorporated into it

What do you think about the use of hormones in agriculture? Some people are worried about their possible effects in terms of food safety and the environment. As a start try the Friends of the Earth web site and type in hormones as a search word.

 

 

Use of hormones in agriculture

Producing embryos for transplanting

Use: to produce large numbers of embryos from an animal with certain desired characteristics, for example a cow with a high milk yield.

Step one

Treat the animal with hormones that increase the number of follicles that develop and the and the number that ovulate.

Step two

When the animal comes into oestrus, carry out artificial insemination.

Step three

6-8 days later collect the embryos by washing them out of the uterus. These can then be transfered to other cows, they can be frozen for storage.

 

Synchronising breeding behaviour

Why do it?

The farmer may wish that all of his animals in a herd come into oestrus at the same time. This means that artificial insemination could be carried out on all of the animals at the same time.

How could you do it?

In implant containing progesterone is inserted into the vagina of each animal in the herd. The corpus luteum continues to function in the ovary and ovulation does not take place. The implants are all removed at the same time, and the animals then all ovulate at the same time.

Increasing milk production

Bovine somatotrophin (BST) is normally produced by the pituitary gland. It increases growth. If cows are injected with BST their udders grow more and produce more milk. They also use a greater proportion of their feed for milk production. The gene for BST has been inserted into a bacterium using the techniques of genetic engineering. Large quantities of the hormone can now be made commercially.