Brainscape's Knowledge GenomeTM

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


See full index

Reproduction > Endocrinology > Flashcards

Endocrinology Flashcards

1
Q

What are the two objectives in reproductive endocrinology in farm animals?

A

Optimize fertility or reinstate normal reproductive activity by - overcoming natural limitations, overcoming disease limitations
Increase reproductive efficiency to improve overall production performance

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

What are the eight ways endocrinology is applied to farm animals?

A 
Reinstating reproductive activity in healthy animals
Induction of puberty in gilts
Synchronization of oestrus/ovulation
Enhancement of embryo survival
Treatment of reproductive diseases
Control of parturition
Increasing the number of gametes
Immunological control of reproduction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What two things could intervention for artificial reproductive control in large animals be?

A

Stimulatory

Inhibitory

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

What do the problems and methods with manipulation of reproduction in large animals need to be?

A

Problem clearly defined - e.g. true anoestrus vs insufficient oestrus detection
Methods specific and ideally reversible - e.g. castration vs immunisation against GnRH

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

What are the two times we want to reinstate reproductive activity in farm animals?

A

Induce oestrus/ovulation in anovulatory post-partum cow

Induce oestrus/ovulation in seasonally anoestrus ewe

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

What is the main way of reinstating reproductive activity in adult healthy animals?

A

Have a sustained increase in LH pulse frequency

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

What does an increase in estradiol cause in farm animals?

A

Negative feedback effect on pulsatile LH

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

How do you treat anovulatory anoestrus/acyclicity in the cow?

A

Ensure true anoestrus not inefficient oestrus detection
Correct underlying factors first
PRID or CIDR for 12 days
PRID or CIDR for 12 days with 500 iu eCG on day of removal

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

How is oestrus/ovulation induced in seasonally anoestrous ewes?

A

Pulsatile GnRH

Manipulation of photoperiod

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

What are some examples of melatonin implants for farm animals?

A

Regulin

Melovine

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

What would an injection of PMSG/eCG at P4 sponge removal cause in ewes?

A

Increase in LH pulse frequency

Induction of ovulation

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

What is the ram effect?

A

Introducing a ram to induce ovulation

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

What is the indication for PG600 (PMSG and hCG) in prepubertal gilts? When is it administered?

A

Puberty induction - at 6-7 months of age, 100 kg bodyweight

Prevention of delayed puberty - 8 months or over

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

What is the indication for PG600 (PMSG and hCG) in first litter sows? When is it administered?

A

Prevention of anoestrus - on day of weaning

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

What is the indication for PG600 (PMSG and hCG) in multiparous and first litter sows? When is it administered?

A

Treatment of anoestrus - at day 8-10 after weaning

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

What is the indication for PG600 (PMSG and hCG) in multiparous and first litter sows (seasonal anoestrus)? When is it administered?

A

Prevention of anoestrus due to seasonal influences - on day of weaning

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

How can oestrus synchronisation be achieved in farm animals?

A

Control of luteal phase

Control of follicular growth

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

What three things does synchronisation of oestrus allow in farm animals?

A

Avoidance of oestrus detection
Fixed time AI
High pregnancy rates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the three ways to synchronise oestrus in farm animals?

A

Prostaglandin F2alpha - shortening of luteal phase
Ovsynch (follicle wave synchorny with PGF2alpha - follicular wave synchrony with GnRH and shortening of luteal phase
Exogenous progesterone with PGF2alpha - follicle wave synchrony with P4 and extension of luteal phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is seen with application of PGF2alpha in farm animals?

A

Rapid decline of progesterone with oestrus 3 to 5 days later

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the possible reasons for poor synchrony using PGF2alpha to synchronise oestrus in farm animals?

A

Luteolysis fails - non-responsive corpus luteum, treated too early in luteal phase, incorrect injection technique
Timing dependent on follicular wave stage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What methods can be used to overcome problems using PGF2alpha for oestrus synchronisation in farm animals?

A

Diagnose corpus luteum, inject and observe

Two doses 11 days apart - ensure responsive corpus luteum presence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How does “Ovsynch” work in farm animals?

A

Use GnRH to synchronise new wave emergence
Apply PGF2alpha to cause luteolysis
GnRH used again to control ovulation time
AI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What four things does establishment of pregnancy affected by?

A

Depends on communication between mother and embryo
Controlled by progesterone
Compromised by insufficient rise in post-ovulatory progesterone - defective corpus luteum
Ruminants (interferon tau) and pigs (oestrogens)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What can be provided to farm animals with luteal deficiency or poor maternal recognition of pregnancy?

A

Progesterone supplementation

GnRH - day 11 in cows, day 9 in ewes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What does cystic ovarian disease occur as a result of in farm animals?

A

Defect in the ovulatory mechanism due to failure of the pre-ovulatory LH surge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What factors contribute to COD in farm animals?

A 
Stress
Lower oestradiol concentrations
Lower hypothalamic sensitivity to oestradiol
Uterine infection
Negative energy balance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the treatment for luteal cysts in farm animals?

A

Prostaglandin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the treatment for follicular cysts in farm animals?

A

NOT manual rupture

GnRH or hCG - luteinises cyst or other follices

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the treatment for pyometra in farm animals and psuedopregnancy in goats?

A

PGF2alpha

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What are the objectives of induced parturition in farm animals?

A

Synchronize calving with seasonal grazing
Ensure calving coincides with availability of labour
Therapeutic termination of pregnancies for clinical reasons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What intiates parturition in the cow, sheep, goat and sow?

A

Foetus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How is parturition started in the cow, sheep, goat and sow?

A

Progesterone production stopped by the corpus luteum or placenta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What determines the timing of onset of parturition in the cow, sheep, goat and sow?

A

Foetal pituitary-adrenal axis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What does foetal stress lead to in the cow, sheep, goat and sow?

A

Rise in foetal ACTH

Induces increase in cortisol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What does a rise in foetal cortisol lead to in farm animals?

A

Increased oestrogen:progesterone ratio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is flushing?

A

Rising plane of nutrition before mating in farm animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

How does flushing work?

A

High energy intake lowers oestradiol concentrations

Promotes FSH release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What does immunisation against androstenedione cause in farm animals?

A

Removes negative feedback effect on hypothalamus and pituitary

40
Q

What does immunisation against GnRH cause in farm animals?

A

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

41
Q

What is the dominant hormone in the follicular phase of the oestrus cycle? Luteal phase?

A

Oestrogen in follicular phase

Progesterone in luteal phase

42
Q

What is the dominant hormone in each stage of the oestrus cycle based on vaginal cytology?

A

Pro-oestrus - oestrogen
Oestrus - oestrogen
Metoestrus - transitional
Dioestrus - Progesterone

43
Q

What is the difference between the bitch and queen in regards to reproductive physiology?

A

Bitch - mono-oestrus, non-seasonal, polytocous, spontaneous ovulator
Queen - seasonally polyoestrus, polytocous, induced ovulator

44
Q

What is follicular development regulated by in the bitch?

A

FSH and LH

Act to synthesise oestradiol

45
Q

What is LH and FSH secretion regulated by in the bitch?

A

GnRH from the hypothalamus

Steroids from the ovaries

46
Q

When does the bitch ovulate?

A

Spontaneously at the end of a variable follicular phase

47
Q

What is the length of each stage of the bitches oestrus cycle?

A

Anoestrus - more than 90 days
Proestrus - 9 days
Estrus - 9 days
Pregnancy/diestrus - 60 days

48
Q

Describe the endocrine events that occur with LH in the follicular phase in the bitch

A

Mid/late anestrus - low LH levels, <1 ng/ml, occasional LH pulses
1 week before proestrus - frequency increases with pulses, occur every 60-90 minutes, levels also increase
Proestrus - LH levels become lower, pulses become less detectable
Late proestrus - LH reach peak levels, 8-15 ng/ml

49
Q

Describe the endocrine events that occur with FSH in the follicular phase in the bitch

A

Mid/late anestrus - FSH levels are high, FSH levels increase throughout anestrus
1 week before proestrus - modest increases in FSH
Proestrus - FSH levels are low
Late proestrus - peak occurs roughly 1 days after LH surge, modest increase in mean level

50
Q

Describe the endocrine events that occur with oestradiol in the follicular phase in the bitch

A

Mid/late anestrus - levels remain low
1 week before proestrus - levels remain low
Proestrus - increase throughout proestrus, go from roughly 10 pg/ml to 120 pg/ml
Late proestrus - peak levels are reached 1-3 days before LH surge
Diestrus - some secretion og oestradiol

51
Q

What can be a good measure of impending ovulation in the bitch?

A

Progesterone measurement

52
Q

Describe the endocrine events that occur with progesterone in the follicular phase in the bitch

A

Mid/late anestrus - progesterone levels are low
1 week before prosestrus - levels remain low
Proestrus - levels increase slowly, 0.2 to 0.8 ng/ml
Late proestrus - 2-4 ng/ml at time of LH surge, 4-10 ng/ml at time of ovulation
Diestrus - peak values of 15-90 ng/ml are reached post ovulation

53
Q

When does the LH surge occur in the bitch?

A

Immediately after peak levels of oestradiol

54
Q

When does estrus sex behaviour occur in the bitch?

A

Immediately after peak in oestradiol

55
Q

What are both LH surge and sex behaviour suggested to be initiated by in the bitch?

A

Decrease in oestrogen:progesterone ratio

56
Q

When does ovulation occur in the bitch?

A

Roughly 2 days after LH surge

Oocytes are immature

57
Q

What could be the signal for completion of 1st meiotic division in the bitch?

A

Rising levels of progesterone

58
Q

What happens to progesterone during the luteal phase in the bitch?

A

Increases and plateaus

Declines rapidly at luteolysis

59
Q

What is the only source of progesterone during pregnancy in the bitch?

A

Corpora lutea

60
Q

Describe the endocrine events that occur in the luteal phase in the bitch

A

LH - regulates progesterone secretion, GnRH agonist leads to luteolysis, GnRH antagonist leads to luteolysis
Progesterone - regulates CL’s ability to secrete progesterone, PR antagonist causes luteolysis, inhibits luteal PGF2alpha secretion, inhibits PGF-R
PRL - regulates progesterone secretion from day 25

61
Q

What does premature luteolysis result in?

A

Early abortion

62
Q

How can luteolysis be induced in the bitch?

A 
PGF2alpha at high doses
Progesterone receptor antagonist
GnRH antagonist
Continuous GnRH agonist
PRL lowering doses of dopmine agonist
63
Q

What is essential for the onset of parturition in pregnant bitches?

A

Rapid pre-partum luteolysis due to feto-placental PGF2alpha release

64
Q

Describe prolactin endocrine events in the bitch

A

Pregnant bitches levels of PRL are 4x greater than in non-pregnant animals
Blocking PRL release causes functional demise of the CL and abortion
Pseudopregnancy clinical signs are associated with an increase in PRL levels

65
Q

When are circulating levels of relaxin elevated in the bitch?

A

21-24 days after the LH surge

66
Q

What is the sole source of relaxin in the bitch?

A

Placenta

Reaches 5 ng/ml in late pregnancy

67
Q

What is the only specific, pregnancy associated protein identified in the dog?

A

Relaxin

68
Q

What is increase in relaxin coincidental with?

A

Rise in PRL

69
Q

Why is not practically possible to use progesterone to control oestrus in the bitch?

A

Not active orally

Short duration of action when given parenterally

70
Q

What do first generation progestagens have a problem with when using to control oestrus in the bitch?

A

Inducing GH secretion

Leads to increased risk of acromegaly, mammary tumours and diabetes mellitus

71
Q

What is a synthetic progestagen designed for oestrus prevention in queens and bitches?

A

Proligestone

72
Q

Why is proligestone particularly suitable for controlling oestrus in companion animals?

A

Strongly anti-gonadotrophic
Weakly progestagenic
Antioestrogenic

73
Q

What is the disadvantage of using testosterone to control osestrus in bitches?

A

Affects subsequent fertility
Causes protrusion of clitoris
Enlarges vulva

74
Q

What is normal in bitches showing clinical signs of pseudopregnancy?

A

Duration of luteal phase

Concentrations of progesterone

75
Q

When do non-pregnant bitches exhibit signs of pseudopregnancy?

A

45 days after the end of oestrus

76
Q

What are the clinical signs of pseudopregnancy in the bitch?

A

Weight gain
Mammary development
Occasional lactation

77
Q

What behavioural changes can bitches exhibit in pseudopregnancy?

A

Nest making
Nursing of inanimate objects
False parturition

78
Q

What are the clinical signs of pseudopregnancy associated with in bitches?

A

Rise in plasma PRL

Noted 6 weeks after the end of oestrus

79
Q

What usually potentiates the development of pseudopregnancy in bitches?

A

Any event leading to fall in progesterone

80
Q

What is the treatment for pseudopregnancy in bitches?

A

Synthetic progestagens to suppress PRL release
Oestrogens and androgens in combination
Dopamine agonists to inhibit PRL release

81
Q

What phase of the oestrus cycle do queens not have?

A

Proestrus

82
Q

What occurs with oestradiol in the follicular phase in the queen?

A

Concentrations are relatively high but variable

83
Q

What occurs with LH upon copulation in the queen?

A

Rapid release from pituitary

Multiple copulations required to produce sufficient LH to induce ovulation

84
Q

Describe progesterone events in the queen

A

Stay at baseline levels till after LH surge
Increase with ovulation and peak after 30 days
Non-pregnant animal the levels decrease
In pregnant levels maintained for a further 25-28 days
Queens that have ovulated don’t return to oestrus until progesterone levels return to baseline

85
Q

What changes in PRL levels occur in the queen?

A

Elevated for the last 20 days of pregnancy
Elevated throughout lactation
No changes in PRL in pseudopregnancy

86
Q

What is the approximate length of the interoestrus interval in the queen?

A

21 days

87
Q

What may the interoestrus interval be a useful guide to in the queen?

A

Whether ovulation or conception has failed to occur

88
Q

How long is the interoestrus interval of queens that ovulate but don’t conceive?

A

Roughly 50 days

89
Q

How long is the luteal phase of mated queens that become pregnant?

A

Roughly 65 days

90
Q

What is described as pseudopregnancy in the queen?

A

Non-pregnant luteal phase

91
Q

When can pseudopregnancy occur in the queen?

A

After mating

After spontaneous ovulation

92
Q

What are the clinical signs of pseudopregnancy in the queen?

A

Absence of oestrus

93
Q

How can hCG be used to control oestrus in the queen?

A

Induces ovulation
Delays subsequent calling
Induces false pregnancy

94
Q

How can androgens be used to control oestrus in the queen?

A

Postpone calling
Induces masculinization
Give daily oral doses roughly 30 days before oestrus

95
Q

How can progesterone be used to control oestrus in the queen?

A

Prevention - give as soon as calling, suppress call, prevents conception
Temporary postponement - give during anoestrus, postpone what follows
Permanent postponement - repeat doses during anoestrus

Reproduction (14 decks)

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