Reproductive technologies

Question 1

What are some reasons for pregnancy diagnosis?

Answer 1

1. Able to identify non-pregnant animals which may be culled
2. Determine if a foetus is viable
3. See size of litter
4. Due dates
5. Foetal sexing

Question 2

How can rectal palpation be used to identify a pregnant animal?

Answer 2

• Horn enlargement in the uterus on the pregnant side
• Fluid
• Membrane slip from day 35
• Feel for a foetus
• Cotyledons

Question 3

On an ultrasound you will see 2 fluid filled structures, what are they?

Answer 3

Uterus and bladder

Question 4

In a hormone essay, give one hormone that could be tested for that would indicate a positive pregnancy diagnosis

Answer 4

Progesterone - day 0-21

Stays high when pregnant

Question 5

When do pregnancy associated proteins start to form?

Answer 5

Once the maternal and foetal junction of the placenta are together
- at day 20 can give a very early indication of pregnancy

Question 6

What are 3 methods of pregnancy diagnosis in small animals?

Answer 6

• Palpation through abdominal wall
• Ultrasonography
• Radiography (more used in overdue)

Question 7

What are some advantages of AI?

Answer 7

• A single bull ejactulate can inseminate 300 females
• Can have a large genetic pool
• Known traits
• Biosecurity
• No male present so less risk of female injury

Question 8

What are some disadvantages of AI?

Answer 8

• Oestrus detection/control
• Handling
• Cost

Question 9

When using an artificial vagina to collect semen what conditions must be correct?

Answer 9

The temperature and pressure

Question 10

In a cow what is the average length of time of oestrus?

Answer 10

9-14 hours

Question 11

After oestrus how long is it until a cow will ovulate?

Answer 11

12-18 hours

Question 12

What is the AM/PM rule in cows?

Answer 12

• If a cow is seen in oestrus in the morning, she will be inseminated that evening
• If a cow is seen in oestrus in the evening, she will be inseminated the following morning

Question 13

In AI, where is semen deposited in the cow?

Answer 13

Through the cervix, to be deposited in the uterine horn

Question 14

Describe day 0 - day 45 of a recipient of an embryo transfer

Answer 14

Day 0 - Reference heat
Day 7 - insert progesterone device 
Day 12 - remove P-device and inject PGF2a
Day 14 - oestrus: AI and GnRH
Day 21-22 - transfer embryos
Day 28 - PGF2a
Day 45 - PD

• Need to be giving regular FSH injections

Question 15

Give 2 methods of controlling litter size

Answer 15

1. Flushing - in the run up to the breeding period put the animal on a more intense diet to increase the chance of a twin ovulation, boosts the LH
2. Progesterone and PMSG - creates a surge of GnRH to get more follicles forming

Question 16

Why would you want to control parturition?

Answer 16

• Narrows the window of birth to supervise and assist if necessary
• Can be used as a ‘one off’ in calves to make them be born earlier to prevent dystocia problems

Question 17

What/when would you give a sow if you wanted birth within 36 hours?

Answer 17

PGF2a on day 114

Question 18

What would you give a combination of in cows to induce parturition?

Answer 18

PGF2a and corticosteroids

Question 19

What is misalliance?

Answer 19

An unwanted pregnancy/mismating