Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Reproduction > Reproductive Endocrinology in Large Animals > Flashcards

Reproductive Endocrinology in Large Animals Flashcards

1
Q

Outline the aims of manipulating reproductive endocrinology in large animals…

A
  1. Reinstating reproductive activity in healthy animals
  2. Induction of puberty
  3. Synchronisation of oestrus
  4. Enhancement of embryo survival
  5. Treatment of reproductive disease
  6. Control of parturition
  7. Increased the number of gametes
  8. Immunological control of reproduction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What hormonal action is necessary to reinstate reproductive activity in healthy adult animals?

A

Sustained increase in LH pulse frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Outline the methods available for achieving a sustained increase in LH pulse frequentcy

A

Continuous infusion of GnRH
PMSG/eCG injection @ P4 sponge removal
Melatonin implants
Ram effects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What may be given to gilts to induce puberty?

A

PG600 (PMSG and eCG) @ 6-7months or 100KG BW

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Outline the relationship between progesterone levels and LH pulse frequency

A

Low progesterone, high LH pulse frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Outline how progesterone can be used to stimulate oestrus…

A

Give then remove (mimic luteal phase)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the levels of natural progesterone at anoestrus…

A

None

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is a PRID?

A

Progesterone-releasing internal device

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is CIDR?

A

Controlled internal drug release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How is prostaglandin F2-alpha used in synchronisation of oestrus?

A

Control (shortening) of luteal phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How is Ovsynch used in synchonisation of oestrus?

A

Follicle wave synchrony and PGF2-alpha
Follicular wave synchrony with GnRH
Control (shortening) of luteal phase with PGF2-alpha

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Outline how PRID/CIDR are used in synchronisation of oestrus…

A

Exogenous progesterone and PGF2-alpha
Follicle wave synchrony with P4
Control (shortening) of luteal phase with PGF2-alpha

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How long are progesterone sponges used for prior to removal?

A

10-12 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Outline the possible reasons for poor synchrony when using PGF2-alpha…

A

Treatment too early in luteal phase (CL not responsive)
Incorrect injection technique
Timing dependent of follicular wave stage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How might PGF1-alpha injections be timed to ensure the presence of a responsive CL?

A

2 injections 11 days apart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How long may melatonin implants take to induce effects?

A

35-70 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

When is natural melatonin secreted?

A

Dark period

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Outline how melatonin affects short day breeders…

A

Melatonin secreted from pineal gland in dark period (16hr)
More frequent GnRH pulses
LH release causes breeding activity

19
Q

Outline the ram efect…

A

Separate rams from ewes for >4weeks
Prime ewes with progesterone 3-5 days before reintroduction (inj/spong)
Ovulation 4-5 days after reintroduction

20
Q

Why are ewes primed with progesterone when synchronising oestrus using the ram effect?

A

To ensure normal, functional CL and maintenance of pregnancy

21
Q

Other than progesterone, which hormone is needed for estalishments of pregnancy in ruminanats?

A

Interferon tau

22
Q

Other than progesterone, which hormone is needed for establishment of pregnancy in pigs?

A

Oestrogens

23
Q

From where is natural PGF2-alpha secreted?

A

Endometrium

24
Q

How does PGF2-alpha reach the ovary?

A

Taken from endometrium to the ovarian artery via the uterine vein (countercurrent system)

25
Q

Outline the available methods for treatment of luteal deficiency/poor maternal recognition of pregnancy…

A

Progesterone supplementation
GnRH
Cows - day 11
Ewes - day 9

26
Q

Why might you inject an animal with PGF2-alpha 1 day before removing a PRID?

A

Allows dominant follicle to ovulate

27
Q

When should progesterone supplementation be given for treatment of luteal deficiency?

A

<6 days after insemination

28
Q

Outline the effect of continued follicular development on establishment of pregnancy…

A

Causes high oestrogen leading to poor establishment of pregnancy

29
Q

How might you treat continued follicular development following establishment of pregnancy?

A

Use GnRH to lyse remaining follicles

30
Q

What is secreted by follicular cysts?

A

Variable concentrations of oestrogens

31
Q

How can GnRH bolus injections be used to synchronise a herd’s follicle development waves?

A

Heavy dose leads to LH surge
Causes ovulation or luteolysis
All animals begin new follicle development wave

32
Q

Why does cystic ovarian disease occur?

A

Result of a defect in the ovulatory mechanism due to the failure of the pre-ovulatory LH surger

33
Q

Outline the factors contributing to cystic ovarian disease…

A 
Stress
Low oestrodial concentration
Low hypothalamic sens to oestrodial
Uterine infection
NEB
34
Q

Outline treatment of luteal cysts…

A

PGF2-alpha

35
Q

Outline treatment of follicular cysts…

A

GnRH or hCG

36
Q

Outline treatment of pyometra (persistent CL)

A

PGF2-alpha

37
Q

Outline treatment of pseudopregnancy in goats (persistent CL)

A

PGF2-alpha

38
Q

Outline the objectives of induced parturition…

A

To synchronise calving with grazing season
To ensure that calving coincides with availability of labour
For therapeutic termination of pregnancy

39
Q

Outline the onset of parturition in the cow/sheep/goat/sow

A

Initiated by foetus
Growth in restricted space leads to foetal stress
Stress leads to a rise in foetal ACTH, and consequently cortisol
Rise in foetal cortisol leads to increase maternal oestrogen:progesterone ratio

40
Q

Outline the 2 methods for increasing ovulation rate…

A

Decrease atresia

Increase follicular recruitment

41
Q

Which agents can be used to induced super ovulation?

A 
Recombinant FSH
pFSH
oFSH
eCG
Purified porcine pituitary extract
42
Q

What is flushing?

A

Rising plane of nutrition before mating to lower oestrogen and promote FSH release

43
Q

Outline the action of androstenedione…

A

Removes negative feedback on hypothalamus and pituitary

44
Q

Outline the purposes of immunisation against GnRH..

A

Inhibits production of gonadotrophins and gonadal steroids
Reduces testicular size and function
Control aggression
Reduces male-associated odours

Reproduction (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions