Brainscape's Knowledge GenomeTM

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


See full index

Reproduction > Horses > Flashcards

Horses Flashcards

1
Q

Where is semen deposited in the horse?

A

In the uterus

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

Unlike the cow, the horns of the mare’s uterus are located where?

A

Over the pelvic brim

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

What is special about the mare’s ovary?

A

It’s inside out! The germinal epithelium is on the inside. This means you can only really palpate CH and follicles, and NOT the CL.

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

Where does the mare’s ovulation occur?

A

All ovulations occur through the ovulation fossa

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

When does cyclicity occur for the mare?

A

In the spring and summer months- cause this means she will foal down the following spring which is what we’re aiming for. She will be in anoestrus for most of the year bar this season.

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

The mare’s cervix has cartinalignous rings, similar to that of a pig. T/F

A

FALSE. THe mare does NOT have circular cartilaginous rings. She does have longitudinal folds.

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

What does the external os of the cervix look like in oestrus?

A

Quite open, swollen and oedmatous (wilted rose)

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

What does the external os of the cervix look like in anoestrus?

A

Tight and closed (closed flower bud)

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

How much of the vulva should be below the pelvic brim?

A

70% of the vulval lips should be below pelvic floor.

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

The angle of declination affects the likelihood of that mare developing ascending infections through the vulval lips. What should this angle be?

A

It should be approx 10%. More than this predisposes her to infection.

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

How is luteolysis exerted?

A

Via a systemic pathway, cf to the local venoarterial exchange in cattle. This means you need a much smaller dose of PG to induce luteolysis than you do in cattle.

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

What happens when there is severe endometrial damage?

A

The CL is prolonged- cause the PG needed to lyse it is meant to come from the endometrium

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

What happens when there is mild irritation of the endometrium?

A

They have short cycles. This is because the irritation can cause the release of small amounts of PGs which may be shortening the cycle.

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

How long does it take for the mare’s uterus to completely involute?

A

About 14 days

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

How long does it take for the embryo to reach the uterus?

A

5-6 days

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

What does TUW stand for?

A

Teasing, Urinating, Weeping

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

What does ESK stand for?

A

Ears Back, Squealing and Kicking

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

What is the dominant hormone in the transitional periods?

A

E2- NO P4

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

What is the only reliable way to advance the transition period?

A

Light manipulation! This period CANNOT be eliminated, only moved forward

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

What is the pathway of light to development of follicles?

A

Light goes through eye, through nerves to pineal gland. Here it decreases the enzymes that produce melatonin, decreases melatonin production, which then stimulate GnRH production from hypothalamus and due to this FSH secretion from pituitary gland, which results in development of follicles.

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

How long does the spring/vernal transition period last for?

A

Typically 60-90 days, this is really variable

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

How much light should be given for how long to implement light manipulation to advance the spring transition period?

A

They need 16 hours of light a day for a minimum of 60 days

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

The LATE transition period can be SLIGHTLY shortened. By how much, and how?

A

Through the use of drugs, from a variety of options like GnRH analogues dopamine antagonists and oestrogen, in conjunction with light therapy. It typically only moves the first ovulation forward by a couple of days to a week, so not that much of a difference.D

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

Do transitional follicles have LH receptors?

A

NO

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

In Australia stallions DO NOT serve before what date? Why?

A

1st of September. This is because the official horse’s birthday is 1st of August. So if we bred mares before this date there would be foals born in like July that then turn one the following month.

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

When is the best window for safe twin ablation?

A

14-16 days post breeding

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

Can a mare ovulate in dioestrus?

A

YES- in early dioestrus. And these can be fertile. There is still P4 present at this time- it is the dominant hormone- so this blocks the behavioural signs of oestrus. In late dioestrus these often lead to prolonged luteal phases.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

When do the endometrial cups develop?

A

At about day 35. They last up until day 100 no matter what, even if the mare subsequently loses the pregnancy.

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

How long can a persistent CL last?

A

35-90 days

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

Is post foaling anoestrus the same thing as lactational anoestrus in horses?

A

NO. Lactational anoestrus occurs in other spp, like cows, but not so much in horses. The anoestrus following foaling is often due to other factors like nutrition.

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

When does the foal heat occur? And why don’t we usually breed on this heat?

A

It occurs 7-14 days following parturition. We don’t often breed on this heat because the uterus takes 14 days to involute completely, and the embryo 5-6 days to get into the uterus. So we’re worried about the hostility of the uterine environment for the embryo.

32
Q

What are 4 reasons that subsequent heats may not occur following the foal heat?

A
  1. Nutrition
  2. Seasonal anoestrus if she has had an early foal. For example if the foal is born is like July, it will still be dark and cold, and she may go back to not cycling.
  3. Persistent CL- may be due to insufficient PG from uterus to cause luteolysis. This could be due to severe endometrial damage/trauma. Or it could be associated with a dioestral ovulation
  4. Foal protection behaviour- she may have a silent heat
33
Q

What 3 types of mares may present with constant oestrus behaviour?

A
  1. Transitional mares
  2. True nymphomaniacs- these often have small ovaries w/ an alternative source of hormones, such as neoplasia. We know it must be an alternative source because ovariectomy doesn’t affect behaviour.
  3. Granulosa thecal cell tumour- this depends on which cell type if present, and whether E2, T4 or inhibin is present. AMH levels usually elevated.
34
Q

We can control the mare’s cycle with PG. When will her CL be susceptible?

A

From 5-6 days

35
Q

What are 3 side effects of PG use?

A
  1. Sweating
  2. Diarrhoea
  3. Colic signs
    Can also cause SM contraction with incorrect dosage
36
Q

To synchronise a herd, when should the PG injections be given?

A

2 shots, 14-16 days apart

37
Q

Response time depends on follicle size at the time of administration. T/F

A

TRUE

38
Q

P4 COMPLETELY prevents ovulation and follicular activity. T/F

A

FALSE

39
Q

If we use progestagens as a drug to manipulate the mare’s cycle, when will she come into oestrus?

A

4-5 days after withdrawal following oral administration for 10-14 days. This is often used in conjunction with oestrogens. EXPENSIVE

40
Q

What 3 drug methods can we use to induce ovulation?

A
  1. hCG. This is an AP in a bottle. The follicles MUST be >35mm, and ovulation occurs 36 +/- 6 hours later. Try to avoid multiple uses/season
  2. Injectable Deslorelin Acetate- this is a hypothalamus in a bottle. The follicles must be >30mm. Ovulation occurs in 40 hours +/- 3 hours
    Can also use products that are a combination of hCG and GnRH, which will stimulate the brain to produce LH.
  3. Deslorelin Acetate (Ovuplant)
    - This is a s/c implant that has been discontinued.
41
Q

Is the GnRH still a commonly used method of preventing ovulation in mares?

A

No, the product has been discontinued? There is an analogous one in the porcine industry.

42
Q

Will an ovariectomy resolve behavioural issues associated with oestrus and ovulation?

A

Not necessarily- steroid hormones come from other places so while she can’t ovulate it may not solve the behavioural issues.

43
Q

What are 2 other methods we can use to prevent ovulation?

A

Oxytocin- prolongs life of CL- artificial recognition of pregnancy
Intrauterine devices- e.g. marbles (high failure rates), U-pod magnetic device. These prolong the life of the CL, cause artificial recognition of pregnancy.

44
Q

How does continuous GnRh stimulation allow for non-permanent oestrus suppression?

A
  • It results in desensitisation of the HPG axis, downregulation of the GnRH receptors and desensitisation of the GnRH receptors. This can be given as an ovuplant. When you remove this she will start cycling again.
45
Q

What does ecbolic mean?

A

Inducing uterine contractions that usually lead to the expulsion of a fetus.

46
Q

How long is the acellular glycoprotein capsule present for?

A

From 6-7 days up until approx 23 days

47
Q

What is the purpose of the acellular glycoprotein capsule?

A
  • It is crucial for embryo survival and maternal recognition of pregnancy. It allows the embryo to move around the uterus, which is important for releasing pregnancy factors that signal the ovary to maintain the CL and pregnancy. There is no elongation of the conceptus due to the capsule.
48
Q

From what day can we reliably detect fetal HB?

A

24

49
Q

What is the most common cause of non-infectious late term abortions?

A

Twins!

50
Q

Why is twin ablation best done in the 14-16 day window?

A

Cause at this point you can still move the embryos around the uterus, so you can isolate one without causing too much damage to the uterus or other embryo.

51
Q

When does attachment of embryo occur?

A

Approx day 35- after this ablation of twins is harder

52
Q

What is the effect of the eCG produced by endometrial cups?

A

It has a LH-like effect which lutenises secondary follicles, causing secondary CLs to develop from about day 36. Can test for this at approx 45 days for preg diagnosis, but it can be inaccurate if eaarly embryonic death has occurred.

53
Q

When will oestrogens be high in the plasma?

A

Approx day 120

54
Q

Progesterone (P4) = progestagens. T/F

A

FALSE- they are NOT the same thing

55
Q

What hormones do the placental and fetal gonads produce?

A

Oestrogens and progestagens

56
Q

What are 3 causes of infectious abortion in horses?

A
  1. EHV1-> respiratory disease
  2. Bacterial- ascending or nocardiform placentitis and leptospirosis
  3. EAFL- Equine Amniotis and Fetal Loss Syndrome
    - This is caterpillar associated abortion, the setae migrate through GIT, into the repro tract and drag bacteria with them. Similar to Mare Reproductive Loss Syndrome (MRLS) in the N hemisphere
57
Q

What are 2 infectious causes of abortion that are exotic to Aus?

A
  1. EIA- abortions at time of infection
  2. Equine Viral Arthritis (EVA)- respiratory infection- abortion 1-4 weeks later
58
Q

What does the zoonotic Chlamidya psttasci cause?

A

Late term abortions and abortion storms. There is a large zoonotic potential w/ aborted mediums.

59
Q

Name 6 non-infectious causes of abortion in mares

A
  1. Undiagnosed twins
  2. Fescue toxicity- this inhibits prolactin and causes prolonged gestationns which can then cause preg loss cause it goes on too long
  3. Umbilical cord torsion- starves fetus of O and nutrients
  4. Placental insufficiency/inadequate attachment
    - can be caused by extensive fibrosis, e.g. mares with old aged uteruses and endometrial cysts
  5. Mare nutrition
  6. Trauma
60
Q

What are the clinical signs for placentitis?

A
  • Vaginal discharge
  • Premature mammary development
  • > thickness of placenta on US
  • Sometimes NO signs
61
Q

What are the clinical signs of EAFL?

A
  • Amionitis and funisitis
  • Mid-late term pregnancy loss or birth of premature, weak foals
62
Q

What are the 5 things we need to do 4 weeks prior to foaling?

A
  1. Vaccinations- Tetanus and strangles, Hendra, Herpes virus (, 7 and 9 months), salmonella and rotavirus if on property
  2. De-worming- prior to moving to clean foaling areas
  3. Move to clean area in which mare will foal- so she can develop immunity for that environment and pass that on through colostrum
  4. Open caslicks
  5. Make sure fetus is still there and in the right position
63
Q

What will be the result of an insufficient placenta?

A

A longer gestation with a smaller foal

64
Q

What happens to milk Ca levels prior to foaling?

A

They increase, and get higher the closer you are to foaling.

65
Q

What does the pH do prior to foaling?

A

It decreases- when it goes from like 7-7.6 to like 6.5 that indicates that she’s ready for foaling.

66
Q

What is the foal doing in stage 1 of parturition?

A

It needs to be alive and vigorous cause in this stage it’s moving around the get in the right position. Mares can show signs of abdominal discomfort.

67
Q

When is stage 2 of parturition initiated?

A

When “waters break”, i.e. rupture of chorioallantois.

68
Q

What is the widest part of the foal?

A

The SHOULDERS. Once this comes out the rest will follow. So the foal needs to come out with one leg slightly in front of the other so this widest part isn’t square on the pelvis.

69
Q

How are the fetal membranes usually delivered?

A

“Inside out”. The allantoic surface is presented rather than the chorionic.

70
Q

How much should the fetal membranes weigh?

A

10% of the foal’s bodyweight

71
Q

How do you check that all of the fetal membranes have been expelled?

A

Lay them out in an F shape to make sure they’re all there. If the membranes are heavy, or placentitis is present, check the foal closely for bacteraemia or septicaemia.

72
Q

How long does stage 2 have to go for for it to be prolonged and be called dystocia?

A

More than 20 minutes

73
Q

What is the normal presentation of a foal?

A

Presentation= anterior
Position= dorso-sacral
Posture= limbs and head position- should come out dolphin-like, one leg slightly in front of the other

74
Q

How long do fetal membranes need to be retained for them to technically be RFMs?

A

More than 3 hours. 5-8 hours requires veterinary intervention, and more than 8 hours will require lavage and antibiotics, and there’s a high risk for further complications

75
Q

Ice boots and heavy bedding are often used for mares with RFMs. Why?

A

Because RFMs increase the risk of mares developing laminitis, and these help prevent/manage that.

Reproduction (10 decks)

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