Infertility

Question 1

What are some congenital anatomical causes of female infertility?

Answer 1

Ovarian hypoplasia
Reproductive dysplasia
Free-martinism/Inter-sex
Persistence of hymen (mare)

Question 2

What are some acquired anatomical causes of female infertility?

Answer 2

Adhesions (e.g. Ovario-bursal, hydrosalpinx)
Endometrial fibrosis
Cystic endometrial hyperplasia (bitch)
Reproductive tract neoplasia (uncommon)

Question 3

What are some pathophysiological causes of female infertility?

Answer 3

Ovarian pathology
Uterine infection
Failure to establish pregnancy

Question 4

What are the typical presentations of a pathological ovary?

Answer 4

Oestrus not observed (ONO)
Barren/empty at pregnancy diagnosis
Persistent oestrus
Irregular oestrous cycles

Question 5

What are the underlying causes of a pathological ovary?

Answer 5

Lack of normal follicular growth/oestradiol

Lack of GnRH/gonadotrophin

Lack of LH surge

Lack of endometrial PGF2A production

(Remember: underlying (patho)physiology might explain this (i.e severe negative energy balance, stress, prolonged prolactin, hypothyroidism))

Question 6

What diagnostic methods are used for pathological ovaries?

Answer 6

Hormone analysis (progesterone)
Ovarian (uterine) palpation
Ovarian ultrasonography

(Accurate diagnosis can be tricky, esp. with cystic ovarian disease)

Question 7

What are the types of pathological ovaries?

Answer 7

Anovulatory anoestrus
Cystic ovarian disease
Persistent CL

Question 8

Describe Anovulatory anoestrus (pathological ovary)

Answer 8

Cow, dog, pig, mare

Lack of cyclicity

Delayed return post-partum / season

Associated with NEB

After pregnancy failure (mare)

Question 9

Describe cystic ovarian disease (pathological ovary)

Answer 9

Cow, sow

Follicular structure that fail to ovulate and persist
- Follicular or Luteal

Question 10

Describe persistent CL (pathological ovary)

Answer 10

Cow, mare

Failure to return to oestrus

CL persists in absence of pregnancy

Question 11

What are the treatment strategies for pathological ovaries?

Answer 11

Promote ovarian function with gonadotrophins (GnRH, eCG)

Mimic luteal phase with progesterone

Induce luteinisation with GnRH/LH

Induce luteolysis with PGF2A

Question 12

What are common infections affecting female fertility?

Answer 12

Endometritis, cervicitis, and vaginitis

Question 13

When do reproductive infections commonly occur?

Answer 13

Post-partum (retained fetal membranes, dystocia) or post-mating

Question 14

What are the effects of reproductive tract infections on fertility?

Answer 14

Subfertility, reduced conception rates & adverse effects on ovarian function

Question 15

What are common treatments for reproductive infections?

Answer 15

Uterine contraction stimulation & antibiotics

Question 16

What are some common causes of conception failure? (failure to establish pregnancy)

Answer 16

Inappropriate timing of AI/mating
Delayed (or lack of) ovulation
Chromosomal abnormalities

Question 17

What are some common causes of early embryonic death? (failure to establish pregnancy)

Answer 17

Poor embryonic development
Failure to secrete maternal recognition signal

Question 18

What management factors influence female infertility?

Answer 18

Oestrus detection accuracy

Timing of mating/AI in relation to ovulation

Number of matings (queens)

Ram:ewe ratio

Seasonality and lactation effects

Stress (handling, heat, transportation)

Question 19

How does negative energy balance affect female fertility?

Answer 19

It can cause anovulatory anoestrus & second litter syndrome by reducing gonadotropin (FSH & LH) & IGF-1 levels, impairing ovarian function & embryo development

Question 20

Why is IGF-1 important for fertility?

Answer 20

IGF-1 links metabolism & reproduction, influencing GnRH secretion (hypothalamus), FSH/LH release (pituitary), follicle growth & steroid production (ovary) & embryo growth & IFN-τ production

Question 21

Which minerals affect female fertility and how?

Answer 21

Copper & Molybdenum toxicity → Impaired reproductive function

Selenium deficiency → Poor embryonic development

Question 22

How do diet-related factors influence female fertility?

Answer 22

Oestrogenic plants (e.g. red clover) → Disrupt normal reproductive hormones

High dietary protein → Increased plasma urea, toxic to oocytes & embryos

Question 23

Define fertility, sterility, subfertility, and infertility

Answer 23

Fertility: Ability to produce offspring

Sterility: Absolute inability to produce offspring

Subfertility: Below-average ability to reproduce

Infertility: Inability to achieve expected reproductive success (not absolute sterility)

Question 24

How can causes of male infertility be classified?

Answer 24

Abnormalities of coitus
- Immaturity and inexperience
- Inability or unwillingness to mount
- Inability to achieve intromission
- Haemospermia

Failure of fertilisation
- Testicular disease
- Sperm abnormalities
- Epididymal lesions
- Accessory gland disease

(Each of these have subcategories)

Question 25

What conditions prevent successful intromission (penetration)?

Answer 25

Question 26

Answer 26

Breeding soundness examination - clinical exam - collect & evaluate semen - ultrasound exam

Question 27

What can you see in this semen evaluation?

Answer 27

Abnormal sperm (mid piece deviation & some dead sperm)

Question 28

Cow is 100 days in milk. Farmer observed oestrus during voluntary wait period but has not observed signs since. She is clean on vaginal exam & rectal ultrasonography of ovaries reveals this. What is your diagnosis? What do we do next?

Answer 28

What is your diagnosis? - Only small follicles visible - No active structures on ovary, possibly anoestrus but difficult to say on one visit alone (could have ovulated too early for CL detection) What do we do next? - OvSynch protocol (mimic luteal phase & allow gonadotrophins to build up)

Question 29

Cow is 50 days in milk. You perform a vaginal & rectal exam (plus ultrasonography). Results are displayed in images What is your diagnosis? How do you treat it? What are the risk factors for this diagnosis?

Answer 29

What is your diagnosis? - Can see that uterus is filled with fluid and speckles - Endometritis (>21d in milk) How do you treat? - Depends on severity, options include prostaglandin, oxytocin & intrauterine antibiotics What are risk factors for this diagnosis? - Dystocia at calving, NEB, poor herd hygiene, retained fetal membranes

Question 30

How is endometritis classified?

Answer 30

Grade 0-3 based on appearance of discharge - 0 = clear mucus - 1 = mucus containing flecks of white pus - 2 = exudate containing <50% white mucopurulent material - 3 = exudate containing >50% white/yellow (sometimes sanguineous) purulent material

Question 31

Cow is presented at 70 days in milk. She is reported to have high activity on her pedometer & displaying signs of nymphomania. What is your presumptive diagnosis? Why? How do we treat this?

Answer 31

What is your presumptive diagnosis? - Follicular cyst Why? - Large fluid filled structure, thin walled, history of nymphomania How do we treat this? - Options include GnRH, progesterone implants & synchronisation programmes

Question 32

Why do we measure testes size?

Answer 32

Indicator of sperm producing ability Smaller testes = less fertile

Question 33

What impacts on testicular size of rams?

Answer 33

Body weight, age, breed, blood testosterone/gonadotrophin concentration, photoperiod, season of birth (smaller in summer) , nutrition

Question 34

What are the 5 T’s of ram MOT?

Answer 34

Toes, teeth, testes, tone, treatment

Question 35

Why is perineal conformation important for fertility in mares?

Answer 35

Poor conformation (e.g. shelving perineum) increases risk of pneumovagina, faecal contamination & ascending infections, which can impair fertility

Question 36

What is the most common bacterial cause of endometritis in mares?

Answer 36

Streptococcus equi subspecies zooepidemicus

Question 37

How is endometritis diagnosed in mares?

Answer 37

Uterine swabs for cytology & culture Ultrasound showing fluid accumulation in uterus

Question 38

What clinical sign indicates a bitch is in proestrus?

Answer 38

Vulvar swelling & bloody discharge

Question 39

What is the best way to determine the optimal breeding time in bitches?

Answer 39

Progesterone measurement & vaginal cytology

Question 40

What type of cells are dominant during oestrus?

Answer 40

80% Anuclear superficial epithelial cells (cornified cells)

Question 41

When is the best time to breed a bitch after detecting the LH surge?

Answer 41

2 and 4 days post-ovulation