Brainscape's Knowledge GenomeTM

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


See full index

Obstetrics and gynecology I & II > Equine reproduction by Kavak > Flashcards

Equine reproduction by Kavak Flashcards

1
Q

Mare Broad Ligament function

A

Functionally connects body and reproductive
organs.
– Nerves, vessels (blood, lymph) run through it
– Connective tissue
– Attaches to the outer layers (utero-ovarian
ligament)
(mesometrium, mesosalpinx, mesovarium)

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

Mare uterine body

A

quite long at approx. 20 cm

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

How many gland complexes per udder half in mares?
How many orifices per teat?

A

Each half of a mare’s udder contains one functional mammary gland, even though each teat has two orifices.

The two orifices lead to separate duct systems within the same gland, but they do not correspond to multiple distinct glands.

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

Describe Mare ovaries

A

have an inside-out structure, meaning the cortex (where follicles develop) is located internally, while the medulla (containing blood vessels, nerves, and connective tissue) is on the outside, a characteristic unique to horses.

The mare’s ovaries also have ovulation fossa, a depression in the surface of the ovary, where ovulation occurs.

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

where are mare oocytes fertilized?

A

captured by the fimbriae and then fertilized in the Ampulla’s folds in the fallopian tube

Isthmus–muscles move the conceptus along.

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

“control point” for fertilized oocytes in mares?

A

Ampullary-isthmic junction is the control point for fertilized oocytes.

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

What molecule/compound does the equine conceptus need to produce in order to pass the control point of the Ampullary-isthmic junction?

A

prostaglandin E

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

Mare cervix length?
What types of folds?

A

10 cm

No transverse folds, only longitudinal folds!

You can not feel the mare cervix in the same way you can grab it in bovine.

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

Mare reproductive classification includes: (4)

A
  • Pregnant
  • Open
  • Barren
  • Maiden
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Mare estrous cycle options (phases): (3)

A
  • Anestrus
  • Diestrus
  • Estrus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What season do mares ovulate in?

A

Spring-summer: April to September

Anovulatory period (anestrus) from December to January.

Reproductive transitional periods from:
– Spring: February - March
– Autumn: October - November

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

When is it non-reproductive season for mares?

A

Anovulatory period (anestrus) from December to January.

Reproductive transitional periods from:
– Spring: February - March
– Autumn: October - November

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

Describe the mare’s ovaries during the non-reproductive season.

A

During Winter Anestrus / Anovulatory period.

Small, hard ovaries with small Follicles < 10 (15)
mm.

Low ovarian activity with Low GnRH, FSH and LH secretion, NOT NONE, just low production.

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

Length of estrous cycle in mares?
Length of estrus in mares?
At what point does estrus occur?
Length of diestrus in mares?

A
  • 21-day estrous cycle
  • Estrus (heat) 5-7 d
  • Ovulation 24-48 hours before end of estrus so day 5-6 of a 7 day estrus.
  • Diestrus 14-16 d
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the Photo period Effect on mares.

A
  • Reproductive activity in spring is stimulated by
    an increasing photoperiod.
  • Mechanism: Alteration of hormone secretion by the pineal gland and hypothalamus. Less melatonin secreted from the pineal gland in spring with longer days.

Melatonin would inhibit GnRh production so the decrease of melatonin causes the Hypothalamus to produce more GnRH which in turn will increase LH and FSH which induce follicular development.

NB Artificial lights change normal cyclicity too!

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

Name 3 husbandry techniques to shorten anestrus.

A
  • Light – lights on 15-16h /day
  • Temperature – heating lamps
  • Feeding – better food, more calories
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe the reproductive transition periods in mares.

A

Reproductive transitional periods from:
– Spring: February - March
– Autumn: October - November

  • 1-3 waves of follicles develop & regress in the transition period.
  • Estrogens are produced by the developing follicles.
  • Irregular/prolonged estrus may be exhibited but this doesn’t equal successful ovulation.
  • 1 follicle eventually ovulates
  • Thereafter, mares ovulate at ~21-day intervals.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

FSH and LH are produced where? And are responsible for what?

A
  • Pituitary anterior lobe (adenohypophysis) – FSH – follicular growth
  • Pituitary anterior lobe– LH – development of
    follicles and finally ovulation after peaking
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Within the breeding season, how many follicular waves occur in each estrous cycle?
How many dominant and secondary follicles

A
  • 1 to 2 follicular “waves” in each cycle
  • End of each cycle – at least 1 dominant follicle and
    several secondary follicles.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Follicle size in mares.

A

over 35 mm (unless small equine), even up to 80 mm

21
Q

AHF ?

A

anovulatory hemorrhagic follicle which is due to ovulatory failure.

a follicle remains in the ovary for a long period of time and gets filled with blood instead of progressing towards ovulation.

it can be normal or pathological.

may also be called Haemorrhagic anovulatory follicle (HAF)

22
Q

Oocyte releases from follicle and caught
by?

A

by the fimbriae of the infundibulum

23
Q

Function of Progesterone in the immediate post-ovulation period? (3)

At what point would it decrease or increase?

A

– Stimulates thickening of endometrium before the fertilized oocyte arrives.

– Inhibits LH production
– Do not inhibit FSH production

– If Non-pregnant, P4 decreases around day 14. Next ovulation will then occur at day 21.

24
Q

Function of corpus luteum: Progesterone production, for initial maintenance of pregnancy.

Maximum function of luteal cells at day?

25
The duration of CL function in the non-pregnant mare is
14 to 16 days Prostaglandin F2alpha is secreted in a pulsatile pattern from the uterus on days 14 to 16 after ovulation, which eliminates function of the CL. A new estrus will kick in by day 21.
26
When does the equine embryo enter the uterus after ovulation?
Almost 6 days after ovulation in mares. In cows, it takes 3-4 days after ovulation.
27
How big do follicles need to be to produce estrogen?
Follicles start to produce oestrogens once they are 20-25 mm in size. * Estrogen Acts on the uterus and the pituitary gland causing: – Heat signs – Relaxation of the cervix – Stimulates smooth muscle contractions – Influences the pituitary to decrease FSH and increase to LH production. LH peak 24-48 h is before ovulation.
28
How long does the corpus luteum produce progesterone for in pregnant mares?
up to 5 months gestation maximum because the placenta begins to produce P4
29
Signs of Estrus in mares.
Most consistent – Elevated tail raise – Winking Other supporting signs – Leaning – Squatting – Standing still – Urinating
30
During palpation In Anestrus, the Ovaries are: The mare Uterus is: The Cervix is:
In Anestrus, the Ovaries are: – small – No follicles The mare Uterus is: – Flat, soft – Thin wall The Cervix is – Flaccid
31
During palpation In Diestrus, the Ovaries are? The mare Uterus is? The Cervix is?
During palpation In Diestrus, the Ovaries are? – Normal size – Several, same size follicles, CL The mare Uterus is? – Good tone, easily palpable – Medium wall thickness The Cervix is? – Firm – No oedema
32
During palpation, in Estrus the ovaries are? The mare Uterus is? The cervix is?
During palpation, in Estrus the ovaries are? – On (two) big follicle – Several small follicles The mare Uterus is? – Flaccid – Thick wall The cervix is? – Flaccid – Oedematous – Shorter, wider, softer
33
When is Filly Puberty?
12-24 months – Ovaries become kidney (bean) shaped (they're oval shaped in neonates). – The hyphothalamo-hypophyseal portal system develops. – FSH is high, LH low
34
Name 6 tactics for Manipulation of Estrus in Mares
1. Artificial Lighting 2. Progestins 3. Prostaglandins 4. HCG (eCG doesnt actually work in horses but does in horses, sheep and rabbits) 5. Deslorelin (GnRH agonist) 6. I.U. Marble ## Footnote A small glass marble (usually 35mm in diameter) can be placed in a mare's uterus to suppress behavioral estrus. Other materials may be used too - stainless steel and plastic spheres have been shown to have similar effect. It is essentially an IUD (intra-uterine device).
35
Why Manipulate Estrus? (6)
* January foals (being born early in the year is better for some horse competitions) * Split transitional estrus * Scheduled breeding * Stallion availability * Poor postpartum fertility * Synchronization for Emrbyo Transfer; preparation for cooled shipped and frozen Semen.
36
How to use Artificial Lighting to bring mares into estrus earlier?
* Needs Enough light to read newsprint – Eliminate shadows * 16 hrs total needed per day * Begin on Dec 1st – Ovulation usually occurs by 90 days after onset. * Nutrition should be good
37
Horse gestation in days and in months.
340 days approx. 11-12 months
38
Describe manipulation of mare estrus using progestin.
* Inhibits LH release – Prolongs Diestrus – Prolongs Estrus – Delays Foal Heat (7-10 days after foaling) – Normalizes a Transitional Cycle * Maintains Pregnancy? Ovulation at 7 to 12 days after cessation of treatment. ## Footnote Product Regu-Mate (altrenogest, progestin analogue)
39
Describe manipulation of mare estrus using Prostaglandin (PGF2α).
* Deactivates receptive CL – Estrus in 2 - 7 days – Ovulation in 2 to 12 days * Side Effects – Uterine Contraction – Colic-like symptoms – Sweating – Ovulation * Risks – Equine – Human
40
Describe manipulation of mare estrus using Human Chorionic Gonadotropin.
* Hastens Ovulation * 1000-3500 units to be given I.V. or I.M. * Follicle needs to be Minimum 35 mm for hCG use. * Ovulation usually by 48h after treatment. * Risk of immunologic reaction (antibody formation). ## Footnote eCG doesnt work on horses for some reason
41
Describe manipulation of mare estrus using Deslorelin Acetate (Ovuplant).
* Hastens Ovulation * 30 mm Follicle * Ovulation 48 to 72h * Expensive 2.2 mg implant placed in the region of the vulva. * Increases IOI by 4 to 6 days unless removed. * No antibody formation
42
Describe manipulation of mare estrus using Intrauterine Marble Placement.
* 30-35 mm minimum diameter * Induces Pseudopregnant state in 40-70% of mares. * Introduce within 24hrs of ovulation. * Remove during Estrus
43
When is foal heat?
7-10 days after foaling
44
How early can you pregnancy check a mare?
You can check a mare for pregnancy as early as 14 days after ovulation using an ultrasound. Can detect the embryonic vesicle as early as day 14, which allows for twin detection as well. Rectal Palpation (18-30 days post-ovulation): A skilled veterinarian can detect changes in the uterus and tone.
45
Describe Estrus Synchronization using prostaglandins and hCG.
* prostaglandins 2 injections, 14 d apart * then once follicles are over 35 mm, inject hCG * Estrus in 2 to 7d * Ovulation in 2 to 12d
46
Describe the use of Regumate or 150 mg Progesterone in Oil + PGF + hCG for induction of estrus and ovulation.
Progestin use: 8-15 days of Regumate upon detection of significant follicular activity (presence of 20mm follicles). * PGF injection on final day ensures luteolysis and ovulation. * then when follicle over 35 mm, inject hCG. * Variable onset of estrus and ovulation * Ovulation by 7- 12d after final treatment.
47
Describe the use of both progesterone and estradiol combination for induction of estrus and ovulation.
This combination is most effective. Progesterone+ 10mg Estradiol i.m. daily then prostaglandin inj. then HCG when follicle over 35mm * Estradiol inhibits follicular growth * Not yet commercially available * Daily injections required * Implant may soon be available
48
Elimination of prostglandins in horses through what organ.
Through the lungs.

Obstetrics and gynecology I & II (29 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions