Brainscape's Knowledge GenomeTM

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


See full index

CAEM Pt. 2 > Exam #3: Repro Pt. 2 > Flashcards

Exam #3: Repro Pt. 2 Flashcards

1
Q

When, and with what, do we ideally breed out mares?

A

> Fresh/cooled semen

  • Up to 48 hrs before to 8 hrs after ovulation
  • Ideal = 24 hours before ovulation

Old methods = breed every other day from day 4 of estrus (2-3 breedings)

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

Gold standard method of predicting when to breed?

A

> Palpation and U/S exam

1) Determine if she’s in heat
2) Examine uterine health
3) Measure follicular size (two measurements, 90 degree angle), measure 2-3 largest follicles at two examinations
4) Examine the cervix

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

How fast do follicles grow per day?

A

3 mm/day

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

What size follicles do mares ovulate?

A

> 40-45 mm

- Range is 30-50 mm

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

At what follicular size do we induce ovulation?

A

When the largest follicle > 35 mm

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

Two drugs we can use to induce ovulation in the mare

A

1) hCG

2) Deslorelin acetate (GnRH analog)

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

Method and time of ovulation with hCG, and sequelae of several uses of hCG

A

> Acts like LH at the ovary
- Ovulate in 36 +/- 4 hours

*Antibodies will develop after multiple administrations (may not work for ET)

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

Method and time of ovulation with deslorelin acetate (GnRH analog)

A

> Mimics the slow LH surge

  • IM or implant (remove after ovulation)
  • Ovulates in 41 +/- 3 hours
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What do you have to keep in mind when you’re trying to manipulate ovulation in the mare?

A

Some mares will ovulate before 35 mm –> inform your client and continually examine the mare

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

Ideal sequence of events for induction of ovulation

A

1) Check the mare - in heat? uterus is healthy?
2) Estimate when she will be > 35 mm
3) Inform the semen collector
4) When the follicle is > 35 mm
a- Confirm semen will be available within 24 hrs
b- Day 0 = give hCG or desorelin
c- Day 1 = breed mare
d- Day 2 = confirm ovulation

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

Signs you’ve correctly predicted the time of ovulation (3)

A

1) Follicles slow their growth rate close to ovulation (may not grow 3 mm/day after admin of hCG and deslorelin)
2) Uterine edema may decrease before ovulation
3) Estradiol decreases before ovulation

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

Things to do post-ovulation (with endometritis and normal mares) (3)

A

1) Examine endometritis mares 4-6 after breeding = may require uterine lavage, oxytocin if fluid is present
2) Normal mares = examine at ovulation check (24 hrs after breeding)
3) Look for the possibility of a second ovulation = follow the second follicle for 1-2 days (or record them)

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

When do we inseminate with frozen semen?

A

> Inseminate 12 hr before to 6 hr after ovulation

  • One dose? Examine the mare every 6 hr after induction of ovulation
  • More than one dose? Inseminate 24 and 36 hrs after hCG, or 24 and 41 hrs after deslorelin
  • Alternative = inseminate at 24 hrs, check for ovulation 36 hrs post-ovulation, inseminate post-ovulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What do we do if the mare isn’t in heat when we check her the first time this cycle?

A
  • Look at the records
  • Confirm the presence of a CL (to ensure she’s not improperly cycling)
  • Follow the largest 2-3 follicles
  • If she’s really in diestrus = PGF-2-alpha, estrus in 5-7 days, ovulation in 9-11 days
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Use of progestins to synchronize estrus

A
  • Used alone or with estradiol (further suppresses FSH)
  • Tx for 15 days = allows CL to regress
  • Tx for 10 days + PGF
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Do we commonly use CIDR’s in mares for estrous synchronization?

A

No - may induce vaginitis

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

Are doses of prostaglandins effective for estrus synchronization?

A

NO = may have two follicular waves

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

Reasons for estrous suppression (3)

A

1) Synchronization protocols = breeding and ET
2) Pain/colic during estrus = periovulatory pain (uncommon)
3) Cycle-related behavior or performance problems = MOST COMMON

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

Treatment of periovulatory pain

A

1) Induce ovulation

2) Anti-inflammatory tx

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

Examples of cycle-related behavior or performance problems

A
  • Intense behavioral signs during estrus
  • Mare is less cooperative or attentive
  • Less tolerance to discomfort = decrease muscular tone and more sensitive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Three main methods of estrous suppression

A

1) Hormonal
2) Immunological
3) Surgical

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

Main hormonal drug we use to suppress estrus?

A

Progesterone - oral, implant, injectable, indirect

Ex: altrenogest oral (SID), injectable P4 in oil, (SID) injectable slow release (every 7-10 days for 2 weeks), injectable altrenogest (every 7-10 days)

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

How does oxytocin suppress estrus?

A

Blocks luteolysis - diestrus continues

Given SID/BID 7-14 days post-ovulation

24
Q

Surgical suppression of estrus

A

> Ovariectomy

  • Permanent
  • Risk during surgery
  • Requires recovery time
  • Doesn’t always solve the problem (decrease estradiol but not progesterone?)
25
Q

Intrauterine device for estrus suppression

A

Glass marble - prevents estrus for up to 90 days

  • Should be removed when she comes into heat
  • Can shatter and lacerate the uterus or other organs
26
Q

Ideal estrus suppression protocol

A
  • Be sure it’s an estrus problem - not management problem

- Try altrenogest first - if it resolves (continues on a regular cycle), continue it’s use

27
Q

How old until we start collecting semen from stallions?

A

20-24 months (any earlier = poor semen quality)

28
Q

When does sperm production peak in the lifetime of the stallion?

A

6 years, stays elevated for most of the animals adult life, may decrease in older stallions (> 20 yrs old)

Peak seasonal = May/June

29
Q

How long does spermatogenesis take?

A

57 days - any insult will take that long to resolve

Sperm transport takes an additional 7-10 days

30
Q

Stallion BSE

A
  • Assess mental and physical ability to mate (history, PE)
  • Musculoskeletal
  • Repro system = internal genitalia (rectal not commonly performed), prepuce/penis, scrotum, libido and sexual stim
  • Clean fossa glandis and urethral sinuses
  • Do not allow the stallion to mount until the penis is fully erect
  • Assess quality and quantity of sperm (collect twice)
  • Screen for infectious diseases = culture prepuce, penis, urethral process, ejaculate
31
Q

What does total scrotal width correlate with?

A

Sperm production, want them to be > 10 cm

32
Q

Venereal diseases we screen for

A
  • Contagious equine metritis (USDA oversight)
  • Equine viral anemia
  • EHV-3
  • Dourine
  • Pseudomonas aeruginosa
  • Klebsiella pneumoniae
33
Q

Components of semen evaluation

A
  • EVERYTHING SHOULD BE WARM
  • Filter and discard gel fraction
  • Measure volume
  • Assess color - presence of blood, urine?
  • Dilute in extender
  • Measure total and progressive motility (not just swimming in circles) - 200x in at least 5 fields
  • Concentration - hemocytometer (grid estimation) or spectrophotometer
  • Morphology w/ staining
  • Stain for other cells (Ex: diff quick)
  • Others = longevity, pH, dead/live, membrane integrity, acrosome status, mitochondria
34
Q

Qualities of a satisfactory potential breeder

A
  • Physically sound
  • Disease free
  • 1 billion motile and normal sperm collected 1 hour after the first ejaculate
35
Q

How to handle extended semen

A

Extend semen 1:1, keep at room temp after extender is added

36
Q

Insemination doses for fresh and cooled semen

A

> Fresh = 10-30 mL, 250-500 million progressive motile sperm, inseminate within a few hours of collection
Cooled = 1 billion sperm with > 60% motility, inseminate within 24-48 hrs

37
Q

Quantity of low dose insemination and where we inseminate it

A

1-20 million progressive motile sperm, at the tip of the horn (uterotubal junction - deep horn with long pipette, hysteroscopic)

38
Q

What is the number of straws we inseminate with frozen semen?

A

8 straws = standard dose

39
Q

Two main reasons we diagnose pregnancy

A

1) Find the open mares to re-breed

2) Management of twin pregnancies

40
Q

Behavioral assessment of pregnancy

A

Anestrus following mating = presumptive pregnancy dx = teast 12, 15, 18, 26 days after estrus, show “teaser cold” and disinterest

False negatives = silent/covert estrus, ineffective teasing, stallion preference

41
Q

True or false - animals that are pregnant do not show estrus

A

False - minority of pregnant mares (5-10%) will show estrus

42
Q

Gold standard of pregnancy diagnosis

A

Transrectal U/S - finding the embryonic vesicle in the uterine lumen

43
Q

At what point past conception does the embryo stop moving?

A

15-16 days post-ovulation, then signals maternal recognition of pregnancy with contact w/ endometrium

44
Q

What occurs if the embryo isn’t mobile around the uterus?

A

Release of PGF and luteolysis

45
Q

Timeline of embryo development during pregnancy diagnosis

A
  • Day 13-15 = motile embryo, dx accuracy is 99%
  • Day 21-24 = embryo is present ventrally in the vesicle
  • Day 24-26 = viability confirmed w/ heartbeat
  • Embryo eventually sits centrally in the vesicle
  • Day 45 = organogenesis
  • Day 60-70 = fetal sexing
46
Q

Things to examine on U/S at day 13-15, 21-14, 30, 60-70

A

> 13-15 = check uterus/ovaries

  • No pregnancy = examine 2-3 days
  • Single vesicle and CL = examine at 21-24 days (will come back into heat if not preg)
  • Single vesicle and two CL = examine 2-3 days (second ovulation)
  • Twins = reduce and re-examine in 21-24 days

> Day 21-24

  • Single vesicle = examine at day 30
  • Twins - deal with immediately

> Day 30 = confirm pregnancy, last change to deal with twins

> Day 60-70 = fetal sexing

47
Q

When is the cut-off to deal with twins and why?

A

Day 30 = last chance before endometrial cups form, begin producing hCG (until day 120) and secondary CL’s to maintain the pregnancy

Loses pregnancy after cups form = won’t come back into heat until the cups regress (day 120)

48
Q

When is the earliest you can palpate to confirm pregnancy with mares?

A

Day 20-25 (when it’s too late for twins)

49
Q

Hormone tests for pregnancy diagnosis

A
  • P4 = would be high (highly suggestive if high when she should be in estrus)
  • eCG in serum (false + are an issue)
  • Estrone sulfate
50
Q

Hormone patterns during pregnancy (P4, estrogens, eCG)

A
  • Increase and then fall of estrogen = produced by fetal gonads
  • CL produces P4, decreases, then saved by endometrial cups eCG, rises with placental P4 production
  • Increases in P4 in last month of pregnancy
  • eCG = increases and decreases early in pregnancy
51
Q

Cause of false heats in late pregnancy

A

Rising E2 and moderate P4 (5 mo of pregnancy) = DON’T BREED

52
Q

Most common cause of twins in the mare

A

Double ovulation (not monozygotic or identical)

More commonly bilateral single ovulations than double unilateral ovulations (crowded ovulatory fossa)

53
Q

Incidence of twins based on breed, repro status, age, etc.

A
  • Breed - high in thoroughbreds, somewhat in quarterhorses
  • Repro status = higher in spring/fall, lower in first months post-partum
  • Age = higher in older mares
  • Significant heritability
54
Q

Is the mare efficient at reducing twins?

A

Yes - esp if they’re in the same horn (one twin wins out)

Different horns = may want to reduce it yourself

55
Q

Why are twins bad? When do probems occur? (3)

A
  • Common cause of fetal mortality = frequently lose one or both fetuses (compete for space and placental exchange)
  • Death of one fetus can lead to the abortion of the other
  • Twin foals born alive = smaller/weaker, more susceptible to infection, slower to develop, higher rate of stillbirth
  • Mares = prone to dystocia and retained fetal membranes, decreased live foaling rates in the following season

Usually occurs between 5-9 mo of gestation when the foals are large in size

56
Q

Methods of twin reduction

A
  • Pinch
  • Manual crushing
  • Surgical removal (not great)
  • Transvaginal U/S guided aspiration
  • Cervical dislocation

CAEM Pt. 2 (27 decks)

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