Repro 2

Question 1

Ovary what type of epithelium and what is within the cortex and medulla

Answer 1

Simple squamous to low columnar to cuboidal epithelium
Cortex
- Has follicles of different stages as well as corpora lutea and corpora albicantia
- In carnivores and rodents cords of hormone producing endocrine cells are present possibly arising for theca interna of degenerated mature follicles
Medulla
- Loose connective tissue with smooth muscle that is continuous with mesovarium
- Less cellular than the cortex

Question 2

establisment of follicles what are the phases and epithelium

Answer 2

1) oogonia - presumptive follicular cells
2) oocyte (meiosis of oogonia)
3) primordial follicle - primary oocyte surrounded by squamous follicular epithelium
2) Primary follicle - primary oocyte surrounded by simple cuboidal (later matures into columnar)
3) Secondary follicle - primary oocyte surrounded by stratified follicular epithelium of membrane granulosa cells, formation of the zona pellucida and differentiation of thecal layer, oocyte and follicle increase in size
4) Tertiary follicle

Question 3

What are the 4 layers of the tertiary follicle

Answer 3

1) Cumulus oophorus: a multilayer of membrane granulosa cells surrounding the oocyte + the oocyte
2) Corona radiata: a layer of radially disposed columnar granulosa cells of the innermost portion of the membrane granulosa cells
3) Membrane granulosa cells: contains FSH receptors and in late tertiary follicles LH receptors
4) Endocrine cells of the theca interna: contain LH receptors and respond to LH stimulation by producing androgens into the membrane granulosa which are converted to oestrogens under influence of FSH
§ Oestrogens create a favourable local environment

Question 4

Uterine tube what lined by and different layers

Answer 4

• Lined by simple columnar or pseudostratified columnar epithelium with cilia and microvilli
  ○ Ciliated cells predominant the ampulla and decrease towards the isthmus
  ○ Provide propulsion for the ovum in the ampulla
• Lamina propria/submucosa comprises of thin layer of loose connective tissue containing plasma, mast cells and eosinophils
  ○ Forms longitudinal folds that are well developed in the ampulla
• Tunica muscularis consists of circular smooth muscle that varies between species
  ○ Larger amount in isthmus -> muscular movement of the ovum
• Vascular tunica serosa is continuous with supporting mesosalpinx

Question 5

What are the 3 layers of the uterus body and horns and what within

Answer 5

1) endometrium - mucosa/submucosa, glands - coiled or branched tubular glands which open into uterine lumen, caruncles (vascular endometrial thickenings form raised mounds on luminal surface)
2) myometrium - tunica muscularis, thicke inner and thin outer longitudinal layer
3) perimetrium - serosa, loose connective tissue layer covered by mesothelium and continuous with mesometrium

Question 6

Cervix what rich in in terms of fibres and cells and what are the 3 layers consisting of

Answer 6

• Thick wall muscular tube that is rich in elastic fibres
• Simple columnar with mucigenic cell and goblet cells
  ○ Produce cervical mucus which contributes the bulk of the vaginal and vestibular mucus present
• Mucosa and submucosa thrown into folds and consist of dense irregular connective tissue that becomes oedematous during oestrus
• Tunica muscularis comprises an inner circular layer is modified to contribute to the interdigiting fold and prominences in small ruminants and the sow
• Tunica serosa of loose connective tissue and a mesothelium surrounds the organ

Question 7

What are the 3 layers of the vagina what what comprised of

Answer 7

1) Mucosa
- Lined by stratified squamous epithelium that increases in thickness at oestrus
- The presence of epithelium and sub-epithelium glands varies between species
2) Tunica muscularis
- Comprises of 2 or 3 layers of smooth muscle, thick inner circular layer and thin poorly defined outer longitudinal layer
○ Sow and carnivores have additional inner longitudinal layer
3) Tunica serosa
- Contains extensive vascular plexuses and is highly innervated

Question 8

Vaginal Epithelium undergoes cyclic changes within the oestrous cycle what occurs in the cow and bitch

Answer 8

Cow
- under influence of progesterone the epithelium is 3-10 layers of cells thick there is an influx of lymphocytes
- Under influence of oestrogen the epithelium thickens by cellular proliferation, but true cornification does not occur
Bitch
- During anoestrus the vaginal epithelium is thin
- During proestrus the epithelium proliferates to 12-20 layers of cells, oestrus the epithelium cornifies
- Late oestrus there is desquamation

Question 9

what are androgens and estrogens

Answer 9

Androgens -> male reproductive hormones
Estrogens -> female reproductive hormones
ANGROGENS CAN BE CONVERTED INTO ESTROGENS

Question 10

What is HCG and LH and how used in pregnancy testings

Answer 10

HCG = human chorionic gonadotrophin
- Produced by the placenta in humans -> test for pregnancy
- Acts similarity to LH -> ovulation induction
LH
Ovulation test - could also be responding to HCG

Question 11

What are the 2 main reasons there will be stallion behvaviour in a gelding

Answer 11

1) 1/3rd maintain the stallion behaviour after being gelded

2) Cryptorchid -> undescended testes -> not gelded properly

Question 12

What are the 4 main tests to determine between stallion and gelding and characteristics of each

Answer 12

1)Testosterone
○ Not as reliable
2) Oestrone sulphate
○ 1 sample -> easier
○ Not reliable in horses under 3 and not a donkey
○ Produced by the testis -> high amount then must have testis tissue -> possible cryptorchid
3) LH response test -> dynamic test
○ Multiple samples -> later so sometimes not as practical
○ High accuracy 95%
4) AMH testings
○ More sensitive and specific then oestrone sulphate
○ New gold standard but not that expensive
○ Produced by sorteli cells

Question 13

what occurs with male from hypothalamus to oestrogens production

Answer 13

Hypothalamus
-> GnRH
Anterior pituitary
-> LH and FHS
Testis
-> LH acts on Leydig cells to produce testosterone -> bind Androgen binding protein (ABP) in the blood
-> FSH stimulates Sertoli cells that produce ABP and AMH -> ABP grab the testosterone and the Sertoli cells convert it to oestrogen

Question 14

list 3 reasons for only having one testis and what is bad

Answer 14

1) Cryptorchid
- Undescended testis -> stays within the abdomen
- There are some inheritance involved -> multiple genes involved
○ Issues if breeding the animal - not reproductively sound
BAD -> can become neoplastic or necrosis within the abdomen due to decrease temperature regulation (possibly)
2) Trauma -> if really damaged just remove
3) Tumour -> removal of testis

Question 15

What is anoestrus and the two types

Answer 15

1. Condition in a female when she does not display oestrus
2. An interval of sexual inactivity between two periods of oestrus in female mammals that breed cyclically
   True anoestrus -> caused by insufficient hormonal stimuli
   Apparent anoestrus -> failure to detect oestrus

Question 16

List 6 things that causes anoestrus

Answer 16

• Lactation
  
  • Season
  • Presence of offspring
  • Stress
  • Pathology
  • (Pregnancy)

Question 17

What are the 4 different types of anoestrus and the species involved with

Answer 17

1. Polyoestrous -> cattle, queen, pig, rodents
2. Seasonal polyoestrous “long day” -> mare -> cycle in summer, anoestrus in winter
3. Seasonal polyoestrous “short day” -> small ruminants -> cycle in winter, anoestrus in summer
4. Monoestrus -> dog, bear, fox independent of the season, long periods of anoestrus between oestrus

Question 18

What is organ is important for seasonal breeders and what is the difference between short and long day breeders

Answer 18

Light is important
- therefore the eye is very important -> registers the light -> sends to pineal gland (melatonin produced at night)
○ Mare will take a year to cycle again after goes blind -> not sure how starts to cycle again
- Long day breeders -> kiss neurons are stimulated by low melatonin -> increase GnRH -> increase FSH and LH -> cycle
- Short day breeders -> kiss neurons are inhibited by low melatonin -> decrease GnRH -> decrease FSH and LH -> DON’T CYCLE

Question 19

Canine oestrus cycle what is the landmark of the beginning of oestrus and how often does it go into oestrus

Answer 19

• LH peak is the landmark!!!!! -> end of follicular phase just before ovulation (36-48 hours later)
  ○ Marks the beginning of oestrus
• Only has oestrus every 7 months

Question 20

Prooestrus in dogs, duration, what occurs and the oestrogen and progesterone levels

Answer 20

• Average duration of 9 days
• This is when bleeding occurs -> not shedding internal lining but due to hyperaemia
• Maximum oestrogen levels - different from others
• Progesterone is starting to rise

Question 21

Oestrus in dogs what occurs in terms of hormone levels and what to test for to determine whether occurred

Answer 21

• Starts the with LH peak (only lasts 12-24 hours so can miss this rise -> therefore test progesterone)
• Also getting increase in progesterone that continues to rise then stays up -> what looking for to detect the LH surge
• Remains elevated for a long time which suggests there isn’t a mechanism for luteolysis

Question 22

What is the difference in progesterone levels between pregnant and non-pregnant dogs

Answer 22

Progesterone levels are similar in pregnant vs non-pregnant
Sudden decrease 65 days after ovulation in pregnant animals due to patriation -> removal of progesterone
THEREFORE CANNOT USE PROGESTERONE TO TEST WHETHER ANIMAL IS PREGNANT OR NOT

Question 23

Doestrus in a dog how long

Answer 23

• Average of 57 days in pregnant and slightly longer in non-pregnant bitch

Question 24

What is a typical timeline from oestrus to fertilisation in dogs

Answer 24

LH surge = day 0 -> first day of oestrus
2-3 days later ovulation occurring -> 1 day to ovulate everything
Another 2-3 days to mature the oocytes
ONLY THEN CAN BE FERTILISED, can be fertilised for 2-3 days
- Lots of notice to breed the dog -> not a rush

Question 25

What are the 2 induced ovulator species and how are each induced

Answer 25

- Alpaca (Camelids) and cats - Something must occur to ovulation ○ Cats -> multiple copulations -> physical act ○ Camelids -> copulation -> factor in the semen therefore can artificial inseminate and will result in ovulation (not in cats) ○ Are exceptions to the rule some oriental breeds can spontaneously ovulate

Question 26

Cats what occurs if they are and aren't mated

Answer 26

○ If not mated within the heat of the week will go into post-oestrus for a week (not on heat), oestrogen and progesterone levels are low § Then New follicular wave will occur increase oestrogen and then will go through week of heat, if not mated repeat cycle ○ If mated then will get LH surge and increase in progesterone and ovulation § If mated and ovulate and do fall pregnant will stay on heat until parturition § If mated and ovulate and don't fall pregnant can have pseudo-pregnancy so progesterone levels remain high but not as long as they do in dogs

Question 27

What are the main behaviours from cows in prooestrus and in oestrus and problem with detecting these

Answer 27

- Prooestrus will start mounting, Restlessness -> odometers, Vocalisation - Oestrus -> cow will be mounted, presence of ruffled hair at base of the tail, rubbed of tail paint Problem - 70% of cows will show heat between 6pm and 6am when handlers aren't present - Therefore use tail paint, heat detection devices (kamar)

Question 28

What is important in teasing the mare

Answer 28

- Teasing records very important to veterinarian - Preferably done by same person every day - Mares must be teased regularly (ideally daily) from 3 days post-partum until 60 day pregnant - Teasing chute/wall is ideal (open front and back) - Mares have individual teasing patterns - Generally use ponies -> horses generally don't like grey ponies

Question 29

What is important in the layout when teasing the mare and 3 behaviours of mares on heat

Answer 29

Layout - Mare needs to have room to kick and not hurt herself - Stallion starts at head and is then allowed to move backwards and ideally rest head on croup Behaviour - Urination - Winking - Standing to be mounted

Question 30

What are 4 main ways canine oestrus detection in performed

Answer 30

- “Breeding reflexes” - behaviour of the dog - vaginal exam- speculum -> look within the vagina looking at the fold, oestrogen high round folds and pink, very wrinkly - exfoliative cytology - keratinised dead cells - serum progesterone levels - to determine LH surge

Question 31

Describe the 2 basic mechanisms for manipulation of the oestrus cycle in cows

Answer 31

1. Inducing luteolysis - luteal phase is shorter -> prostaglandin F2alpha ○ All animals will be refractory (not respond) to effects after the first 5 days after ovulation ○ Day 6-17 days of the cycle will shorten the luteal phase, decrease the time to get the animal in heat 2. Prolonging luteal phase - progesterone device placed into uterus ○ Rapid uptake of progesterone ○ Stays elevated and keep in 7-12 days before removed § Within a few hours after removal progesterone will go down again § When remove give a shot of prostaglandin just in case has a corpus luteum so the progesterone levels decrease

Question 32

What is involved in the presynch cycle in cows

Answer 32

1. If give to herd PGF2alpha to regress existing CL and induce new ovulation (the rest) ○ 20% will be in heat -> won't respond as no corpus luteum ○ 1st 5 days of ovulation also won't respond -> 25% 2. If give again 14 days later -> GET RID OF ALL CL ○ The cows not responding to 1st lot will now have corpus luteum and respond ○ Others who were in 1st 5 days will now be in heat and ready to mate so don't need to work

Question 33

What are the 4 steps in the offsynch cycle and what occurs in each group and what conception rate does it result in

Answer 33

1. Give GnRH 12 days after last PGF2alpha Group A - Cause ovulation in cows that have LH receptors and large follicles Group B - Or increase LH levels but without ovulation as don't have enough LH receptors 2. 7 days after this give PGF2alpha Group A - regress new CL from previous GnRH injection Group B - Those that didn't have enough LH receptors should have ovulated by themselves and have CL which need to regress - Now should all be luteolysis 3. 2 days later give then GnRH BOTH - ovulation of the dominant follicle 4. 16 hours later INSEMINATION -> sperm in tract before ovulation (occurs in 24-32 hours) - Results in 30-40% conception

Question 34

What is the main cycling technique used in horses, why and the 2 drugs

Answer 34

use ovulation induction - only have to breed a mare once, expensive but thoroughbred stallions are very busy 1. human chorionic gonadotropins (HCG) - acts like LH therefore need the LH receptors 2. GnRH analogue - common, more expensive, mare ovulate between 42-48 hours if given as soon as largest follicle is 30mm

Question 35

What is involved in the whitten effect (ram effect) and how use

Answer 35

- If ewes are joined outside the breeding season can be used to stimulate oestrus - Ram pheromones need to be kept away from ewes for at least 1 month - Once join ewes that have been isolated will start cycling - whitten effect - If using AI can use teasers that can be used instead of intact rams and can put a marker on to see which ewes are on heat as they have been marked by the teasers (vasectomised) - Most ewes come into heat 17-25 days after first ram or teaser introduction

Question 36

What are the 2 main ways seasonal breeders can be modified and what occurs in mares and sheep

Answer 36

- Small ruminants can either be kept inside where light manipulated on order to stimulate shorter days or melatonin implants (stimulate the hypothalamic-pituitary axis) 1) mares 2) sheep

Question 37

What occurs with mares in terms of changing their oestrus cycle

Answer 37

artificially extended day length most common - Kept under a 16 hour regimen from about 1st June - Brings about 2 months advantage in the onset of first ovulation of the season § Mares still will go through a period of "transitional oestrus" -> mare undergo at least 3 follicular waves of follicular growth without the occurrence of ovulation

Question 38

What occurs with sheep in terms of changing their oestrus cycle

Answer 38

mainly use melatonin -> need to increase | - To control timing of lambing -> may do spring and autumn lambing

Question 39

What are the 3 major steps in artifical insemination

Answer 39

1. Collection of semen from the male 2. Preservation and extension of sperm 3. Insemination of the female

Question 40

Semen extender what is its function, what has within and the 3 main reasons it is used

Answer 40

- Added to protect the sperm if not inseminated immediately - Provides nutrients and cooling buffers if the semen in to be cooled - If frozen at cryoprotectants have to be added - Generally has -> buffer, energy in form of sugar and antibiotics Semen extender is used for multiple reasons: 1. - Ejaculate can be split into multiple doses 2. - increases longevity of sperm outside the reproductive tract 3. - allows shipping of semen (overnight if fresh chilled; for any amount of time if frozen)

Question 41

What is the duration of days that sperm remain fertile in the female reproductive tract for cows, mare, bitch and women

Answer 41

Cow - 1.5 - 2 Mare - 4-5 Bitch - 9-11 Woman - 5-6

Question 42

What is involved with fresh vs frozen sperms

Answer 42

Frozen - can stay indefinitely but lose sperm during freezing and thawing process so need larger amount Fresh - timing has to be better (within 24 hours)

Question 43

Sperm sexing what is involved, how done and accuracy

Answer 43

- Separation of X and Y bearing spermatozoa by flow cytometry - X chromosome has more DNA therefore and takes up more dye, emits more light and therefore computer reads as X sperm directing it to one side while Y sperm to another - Close to 90% accuracy

Question 44

Reproductive technologies list and describe 6

Answer 44

1. Classic in vitro fertilization (IVF) -> egg and sperm are incubated together in small petri dish 2. Intracytoplasmic sperm injection (ICSI) -> injecting one sperm into the egg 3. Gamete intrafallopian transfer (GIFT) -> egg and sperm are transferred into uterine tube 4. Embryo splitting -> take one egg with only a few cells and split get two eggs 5. Somatic nuclear transfer (SCNT) -> nucleus from a donor adult cell is transferred to an egg that has been enucleated, when divides normally it is transferred into uterus of surrogate mother 6. Embryo transfer -> allows dam to have more offspring in a given year therefore allows propagation of genetically valuable individuals - More common in bovines

Question 45

Avian reproduction where gonads, do they have a penis and what are the sex chromosomes

Answer 45

- Internal gonads – both sexes - site in front of the kidney - Males – no Penis (* some have a phallus -> ducks, emus) - Males ZZ, Females ZW chromosome ○ Female are heterozygous

Question 46

What is the cloaca made from (3 areas) and what is important about it

Answer 46

1. coprodeum 2. urodeum -> reproductive tract, ureters 3. proctodeum -> final area Urine, eggs and faeces, shoudln't have any faeces or lumps and bumps

Question 47

Avian female anatomy what is variation in species with ovary and is there a CL

Answer 47

- Only left ovary and oviduct in most species - Kiwi have 2 ovaries, raptors have right ovary - No corpus luteum is formed after ovulation -> don't need to support placentation

Question 48

What are the 5 main ways to sex a bird

Answer 48

``` colour - Sere (on the nares) -> budgie ○ Male -> blue ○ Female -> brown - Electas parrot ○ Male = green ○ Female = red 2. DNA PCR 3. X-ray - hard to differentiate inactive gonads 4. endoscope -> lateral approach in front of right hip 5. lay egg -> FEMALE ```

Question 49

What occurs in each stage of the avian female reproductive tract

Answer 49

1) Infundibulum -> catches the ovum and bring into oviduct - If miss move into abdomen cavity (resorbed) 2) Chalazae -> membrane attachments to hold the yolk centrally 3) Magnum -> produces the egg white -> thick on inside near yolk and thin on outside 4) Isthmus -> shell membrane -> 1 wraps around whites, within the inside of the egg shell 5) Uterus -> shell is deposited 6) Vagina -> close to keep oviduct sterile, until lay then relax and open

Question 50

What is the main endogenous and 4 main exogenous cues for avian reproduction

Answer 50

1.) Endogenous cues - biological cycles – hormones, behavioural controls (migration etc) 2). Exogenous cues 1. Predictive factors – encourage gonads to prepare for breeding ○ e.g. photoperiod (chicken), rainfall (desert species) 2. Essential supplementary factors ○ e.g. social cues, nutrition (increased energy, protein, vitamins), rainfall, nest site availability 3. Synchronising factors ○ e.g. social interaction between pair - courting 4. Modifying factors e.g. loss of mate, disruption of nest (modifying factor, negative or reset - build new nest)

Question 51

What is vitellogenesis

Answer 51

making of the egg yolk in avian reproduction

Question 52

What is brooding and what hormonal changes occur

Answer 52

Decreasing levels of hormones such as oestradiol, LH, progesterone induces "broodiness" where hen stops laying and incubates eggs

Question 53

Calcium metabolism in birds, what needed for, what occurs during lay and how compensate

Answer 53

- Calcium for shell sourced from diet or from skeleton - During lay, dietary calcium needs to be 3-4% for the majority of calcium to come from intestines - Vitamin D3 promotes calcium absorption from intestines and deposition of medullary bone - A laying bird can use its entire serum calcium in 15 minutes ○ Medullary bone is a buffer for maintaining serum calcium ○ When medullary bone exhausted cortical bone is used § Excessive loss of cortical bone -> osteoporosis -> not desirable

Question 54

What occurs pre and during lay for birds to reach calcium requirement

Answer 54

Pre-lay - Birds will seek out calcium rich food prior to lay - Oestrogens and androgens prior to laying increases medullary bone deposition - Radiographically, medullary cavity of bones becomes more radio-dense During Lay - Oestrogen and prostaglandins increase mobilisation of medullary bone and serum calcium.

Question 55

What are the consequences of running low in calcium midlay in a bird

Answer 55

○ Weak-shelled eggs -> change in shape, wrinkled, possibly get infected -> Reduced hatchability ○ Poor smooth muscle contractility – > Dystocia

Question 56

Domestic chicken how often lay, sexual maturity, how long between eggs, #1 breeding cue and how many eggs per year

Answer 56

- Continuous layer - Sexual maturity: 18-20 weeks - Cycle for an egg -> 24 hours - #1 Breeding cue: Photoperiod Commercial layers: 330 eggs/year

Question 57

Budgerigar how often lay, sexual maturity, #1 breeding cue and how many eggs how often

Answer 57

- Seasonal, Determinant layer (set number of eggs laid in a clutch) - Sexual maturity: 3-4 months - #1 Breeding cue: Rainfall and feed availability - natural environment is the desert bush - Lay 4-6 eggs, egg every 2nd day.

Question 58

Mallee fowl how often lay, clutch size, sexual maturity and breeding cue

Answer 58

- Seasonal, determinant layer - Clutch: 15-25 - Sexual maturity: 3 years - Breeding cue: rainfall while nest mound open (winter)

Question 59

List 5 main ways you can turn off laying in domestic pet birds such as a cockatiel

Answer 59

- Reduce energy component in the food - GnRH agonist -> downregulate pituitary reacting to GnRH - Remove the nest box - 8 hour photoperiod -> cover the cage at certain times - May have mated with the person -> decrease courting behaviours such as feeding (others feed), stroking the bird Could also be mirror and fluffy toy

Question 60

what is the mechanism of an erection and what occurs in a musculocavernous and fibroelastic penis (which species has which)

Answer 60

- Increase blood flow to cavernous tissue + decrease venous return = engorgement of erectile tissue ○ Results = erection - Musculocavernous penis = increase width, length and rigidity ○ Horse penis - Fibroelastic penis = some increase rigidity and straightening of sigmoid flexure ○ Ruminants and pigs

Question 61

Coitus in the dog what occurs

Answer 61

- The male and female remain "tied" together due to: ○ Bulbus glandis remains engorged after the turns -> tied (nothing can be done until erection goes down) § Contraction of the muscle at the base of the penis prevent venosus outflow from the bulbus glandis § Also the sphincter muscle of the vulva constricts compressing the dorsal vein of the penis and preventing blood from leaving

Question 62

What are the 4 functions of the epidiymis

Answer 62

- Water absorption - Spermatozoal transport - Blood-epididymis barrier - Spermatozoal maturation ○ Acquisition of motility § Structural changes -> if have proximal droplet (near the head) then malfunction here § Physiologic changes

Question 63

Spermatozoal motility how does it occur

Answer 63

- ATP produced by mitochondria diffuse the entire length of the flagellum - Glycolytic enzymes have been identified in fibrous sheath and outer dense fibers – pathway is essential under anaerobic conditions - Possibly a adenlyate kinase shuttle may assist in rapid distribution of mitochondrial produced ATP

Question 64

Spermatozoal metabolism what occurs and why increase

Answer 64

- Constant supply of energy required for cellular housekeeping - Aerobic and anaerobic capacity - Increased requirement with activated motility - Further increase required for hyperactivation

Question 65

What are the 3 main things that occurs in the immediate transport of sperm

Answer 65

- Once sperm are deposited after copulation they are immediately exposed to a series of defence mechanisms from the female - Only the “best” make it to the site of fertilization. - introduction of semen there is always also an introduction of microorganisms, which originate from the male (e.g. outside of his penis) or the female herself (caudal vagina)

Question 66

What is involved with the immediate transport of sperm what occurs with the "best" making it to fetilisation

Answer 66

○ Immediately, some are lost retrogradely and others phagocytosed by neutrophils and macrophages. § Phagocytosis and retrograde transport are the two ways by which sperm are lost from the reproductive tract. □ Neutrophils sequester under the mucosa of the vagina and uterus as a result of oestrogen exposure

Question 67

What occurs with the introduction of microorganisms through sex

Answer 67

○ From about 3 hours of semen deposition a marked neutrophil reaction happens and they are not only attacking microorganisms but also sperm and the seminal plasma (needs to be removed doesn't remain in the uterus) § They do not distinguish between live and dead spermatozoa and can phagocytose multiple sperm § The inflammatory reaction usually resolved within 48 hours □ If not leads to post-breeding endometritis = "post-mating induced endometritis (PMIE)", common condition in mares

Question 68

What occurs in the cervix in terms of sperm if it is deposited in the vagina

Answer 68

- Oestrogen leads to production of sulomucins from the apical portion of the cervical mucosa, viscous substance directed towards lumen in caudal direction, if sperm get into this they are flushed out - Privileged pathways -> less viscous substance, sialomucin, is produced in the cervical crypts and facilities easier transport route for the sperm ○ Removal of non-motile sperm -> sperm have to be actively swimming through the mucus ○ Removal of some abnormalities

Question 69

What occurs in the sperm in the uterus

Answer 69

1) Capacitation initiated -> decapacitated sperm are not fertile ○ Plasma membrane of epididymal spermatozoa contains complement of surface molecules ○ If sperm is ejaculated they get into contact with seminal plasma and surface molecules get coated by seminal plasma proteins ○ When sperm exposed to the female tract environment the seminal plasma molecules and surface molecules are removed § They then expose portions of molecules, which are able to bind to the zona pellucida -> why is necessary ○ It is important to note that capacitated sperm can become decapacitated if incubated in the appropriate media (e.g. seminal plasma) 2) Phagocytosis

Question 70

What occurs in the oviduct in terms of sperm during sex

Answer 70

- Rapid and sustained transport of sperm in oviduct ○ Caused by strong contraction of the uterine muscle in response to copulation § Dam's oestradiol and prostaglandins in the semen (PGF2alpha and PGE1 - Not just the first in oviduct fertilises the egg ○ Important transport seems to be the slow "trickle" of sperm that come from reservoirs in the cervix and the uterotubal junction (UTJ) § Maybe to avoid the initiate inflammatory reaction

Question 71

What are the 3 series of events during fertilisation that leads to them becoming fertile

Answer 71

1) Hyperactive motility -> in ampulla the pattern changes from a straight line to not linear, random movement -> more likely to bump into egg 2) Bind to zona pellucida -> sperm zona binding region (ZBR) reacts with Zona pellucida protein 3 (ZP3) and causes physical attachment of the sperm -> leads to acrosome reaction 3) acrosome reaction -> membrane overlying the acrosomal membrane begins to fuse with outer acrosomal membrane, leads to vesiculation and pore formation so acrosomal contents can reach the zona pellucida and facilitate sperms penetration through it -> need multiple sperm to produce enzymes that help break down zona pellucida (more than one sperm binds but only one sperm enters) § After acrosome reaction the vesicles slough and the inner acrosomal membrane and the post-nuclear cap are left behind

Question 72

What occurs once the sperm are fertile, how does it fertilise the egg

Answer 72

1) spermatozoon penetrates -> the sperm equatorial membrane fuses with oocytes plasma membrane and the sperm is engulfed § Leads to cortical block which is critical to prevent polyspermy (more than one sperm fertilising an egg) □ Cortical granules are released into perivitelline space resulting in impenetrable zona pellucida 2) male and female pronuclear form -> after fusion sperms nuclear membrane disappears and the nucleus decondenses and male pronucleus formed § Male pronucleus then fuses with female pronucleus -> Syngamy -> successful fertilisation Generally lots more fertilisation then pregnancies -> lots can go wrong after this point

Question 73

What is the conceptus

Answer 73

- Everything that develops from zygote "product of conception" - Embryo/foetus - Extra-embryonic membranes ○ Amnion ○ Allantois ○ Chorion ○ Yolk sac

Question 74

what is the embryo

Answer 74

- Organism in early stages of development (blasturation, gastrulation and organogenesis) - Usually not yet identifiable as membrane of a species

Question 75

what is the foetus

Answer 75

- Controversial definition: often just "more advanced form of an embryo" ○ Can be recognised as member of the species ○ OR ○ From organogenesis to term - Foetal stage ends with expulsion from uterus -> neonate

Question 76

What are the 5 main steps after fertilisation to attachment

Answer 76

1) development within zona pellucida 2) hatching of the blastocyst 3) formation of the extraembryonic membrane 4) maternal recognition of pregnancy 5) attachment

Question 77

What are the 3 main steps with the development within the zona pellucida

Answer 77

1) large amount of cytoplasm present in the ootid (ootid= stage when male and female pronuclei are present in the oocyte); from here on cytoplasm will only be partitioned in embryonic cleavage (not more generated); once pronuclei fuse, the oocyte is called a zygote 2) First cleavage generates a 2-cell embryo whose cells are called blastomeres 3) Blastomeres then undergo division -> 4, 8, 16-cell phase

Question 78

what occurs in the development within zona pellucida 8 cell phase

Answer 78

§ At 8 cell embryo are totipotent -> at this stage each cell can form a foetus □ Identical twins are derived if a 2-cell embryo splits and each blastomere develops independently into offspring - monozygotic ® Heterozygous twins -> double ovulation and both fertilised - different mechanism

Question 79

what occurs in the development within zona pellucida 16 cell phase

Answer 79

§ At 16 cell phase the embryo is known as morula □ Outer and inner cells become compacted to two distinct cell population -> outer and inner cells ® Inner cells - develop gap junction (cavity) which facilitate cell-to-cell communication ® Outer cells - develop tight junctions (cell to cell adhesions) □ Sodium pump believed to be responsible for increase in sodium in water within embryo -> form fluid filled cavity formed called blastocoel

Question 80

What occurs with the development within the onal pullucida and once the distinct cavity is formed

Answer 80

§ Once distinct cavity is visible the embryo is called a blastocyst □ Inner cells - form inner cell mass (ICM), which give rise to embryo proper □ Outer cell -> form the trophoblast cells, which give rise to the chorion (foetal part of the placenta)

Question 81

Hatching of the blastocyst what are the 2 main stages and the 3 main things that allows this to occur

Answer 81

1) Rupture of the blastocyst 1. As cells keep undergoing mitoses and fluid inside increasing the pressure within the zona pellucida 2. Outer trophoblast cells producing proteolytic enzymes, weaken the zona pellucida 3. Blastocyst contracts and relaxes causing pressure pulses 2) Blastocyst then hatches from zona pellucida § Once hatch undergo rapid growth

Question 82

location pre and post hatching of the blastocyst

Answer 82

- Everything before hatched blastocyst are in the oviduct | - Past this point go into uterus and further development there

Question 83

What are the 6 steps in the formation of the extraembryonic membranes

Answer 83

1. Thin lining beneath the inner cell mass (becomes the embryo) grows around the blastocyst cavity § Forms Endoderm and mesoderm 2. Once endoderm finished growing it has form the yolk sac § Mesoderm starts growing outwards 3. Mesoderm grows and pushes against trophectoderm (previously called trophoblast cells) § formation of little “wings” around the embryo, called amniotic folds -> folding of the amnion -> formed from ectoderm and mesoderm 4. Mesoderm now surrounds the yolk sac and amniotic folds continue to grow upwards around embryo § The allantois forms as an outgrowth from the embryonic hindgut 5. Yolk sac regresses, allantois grows, amniotic folds grow and eventually fuse 6. The amniotic folds join above the embryo, forming the amniotic cavity right around the embryo.

Question 84

Maternal recognition of pregnancy in ruminants what are the 2 main mechanisms

Answer 84

§ Has the countercurrent mechanism therefore PGF2alpha needs to be prevented □ The free floating (thread-like) blastocyst secretes interferon-τ (ovine and bovine IFN-τ, respectively), which binds to the endometrium and prevents oxytocin receptor synthesis. ® Remember that OT-receptors are critical in the process of luteolysis. So preventing OT-receptor synthesis, prevents PGF2α production. □ IFN-τ also stimulates uterine gland secretion and therefore provides embryonic support. It is NOT luteotropic, meaning it does not directly act on the CL to enhance its function.

Question 85

Maternal recognition of pregnancy in ruminants what is needed, what occurs in conceptus present or without a conceptus

Answer 85

§ The pregnancy needs to establish ipsilateral to the corpus luteum (CL) for this to work successfully □ Otherwise PGF2α will be produced from horn closest to CL and CL will be lost. - If no conceptus present § luteolysis occurs at around day 15/16, progesterone levels drop and the cow will return to oestrus within a few days - If conceptus is present and maternal recognition was successful § progesterone stays elevated because luteolysis don't occur § Oxytocin receptor expression is blocked by IFN-t and therefore PGF2alpha secretion is not sufficient to induce luteolysis

Question 86

why is maternal recognition different in the pig

Answer 86

- Pig is different from ruminants as even pregnant animals, PGF2alpha is produced DOES NOT REACH THE OVARY THOUGH doesn't have the counter-current exchange

Question 87

what occurs when pigs don't get pregnant

Answer 87

§ Oxytocin is produced and promotes PGF2alpha production by the endometrium § PGF2alpha diffuses to the capillaries and is drained to uterine vein, the transported to ovaries and cause luteolysis

Question 88

what occurs in terms of maternal recognition if pig is pregnant

Answer 88

§ The blastocyst produce oestradiol that causes PGF2alpha to be rerouted into the endometrium □ Instead of reaching blood vessels in the endometrium (and CL's) as in non-pregnant it is put into the lumen of the endometrium and has NO EFFECT ON CL ® Need to reroute all PGF2alpha produced and at least 2 blastocysts (conceptus) need to be present IN EACH HORN, so 4 in total - exam question ◊ If less than not enough oestradiol is produced by the conceptuses and luteolysis occurs

Question 89

What occurs with maternal recognition in the horse

Answer 89

§ Blastocyst does not elongate but instead stays in a spherical shape where stays for 15-16 days □ Due to embryo surrounded by tough glycoprotein capsule -> surrounds the zona pellucida § In order to make contact with the endometrium and prevent PGF2α –production, the conceptus has to migrate all over the endometrial surface -> can move between uterine horns □ Uterine contractions that move it § Between days 12 and 14 after ovulation (critical stage) it needs to make contact with every cm of the endometrium 12 to 14 times a day □ If that does not happen, PGF2α is produced and luteolysis occur □ Cysts within the uterine horn can prevent the movement of the conceptus and result in failure to recognise § After day 15-16 and have signalled presence will get stuck generally on the base of the uterine horn (fixation) and will lose the spherical shape as loss the outer tough glycoprotein capsule

Question 90

what occurs in terms of maternal recognition in canine

Answer 90

- The progesterone profile in pregnant and non-pregnant animals is very similar - Every bitch goes either through pregnancy or pseudopregnancy after ovulation - Therefore, it is believed that no maternal recognition of pregnancy is present in the bitch.

Question 91

What are the 8 layers of teh scrotum, testis and epididymis

Answer 91

1. Skin 2. Tunica dortos (muscle) 3. Fascia 4. Parietal tunica vaginalis 5. Visceral tunica vaginalis 6. Tunica albuginea (covering the testes immediately) 7. Mediastinum of the testis - where the rete testis sits 8. Testicular parenchyma

Question 92

What are the 6 steps in teh movement of sperm from origin to penis

Answer 92

1. Seminiferous tubules 2. Rete testis (tube in the mediastinum) 3. Efferent ductules (head of the epididymis) 4. Duct of the epididymis ○ Where sperm matures, coils through the epididymis from the head -> body -> tail 5. Ductus deferens (the sperm is mature at this point) 6. Urethra

Question 93

What are the 4 layers of the seminiferous tubules

Answer 93

1. Lamina propria with myofibroblasts (myoid muscle cells) on the outside 2. Stratified germinal epithelium 3. Spermatogenic cells or germ cells ○ release sperm into the lumen -> produce haploid cells § Mitotic and meiosis division 4. Supportive (sertoli/sustentacular) cells ○ Irregular shape - elongated processes ○ Tight junctions

Question 94

What are the 5 main functions of the seminiferous tubules

Answer 94

1. Provide a barrier between lumen and the rest of the body - immunological - Blood-testis barrier - tight-junctions □ Stop the body from sensing the presence of sperm - NOT SELF 2. nutrients, protection and facilitate release of Spermatogenic cells 3. hormones - regulation of interstitial endocrine cells 4. phagocytic capability and engulf by products of Spermatogenic activity 5. produce small amounts of oestrogen

Question 95

what is involved with the blood-testis barrier

Answer 95

- Tight junctions between adjacent Sertoli cells create separate apical and basal compartments - boundary between these is the barrier ○ Basal region exposed to the body tissue environment -> multiplication of spermatogenic cells occurs here ○ Apical regions is isolated from the body tissue fluid and general humoral/immunogenic effects -> meiosis of germ cells and development of spermatozoa (spermatogenesis) occurs here - Each sperm passes through this barrier without causing disruption - cell junctions open and immediately close behind each cell

Question 96

rete testis, efferent ductules, duct of the epididymis and ductus deferens what made up of

Answer 96

Rete testis - Lined by simple squamous to columnar epithelium - Where most of the testicular fluid is reabsorbed in the head of the epididymis Efferent ductules - Lines by simple columnar epithelium with cilia (motility) Duct of the epididymis - Lines by pseudostratified epithelium comprising columnar principle cell with apical microvilli - Convulsions of the epididymal duct are bound together in a connective tissue and muscle matrix enclosed by a capsule or tunica albuginea Ductus deferens - Thin muscular tubes mainly muscle and mucosa generally forms longitudinal folds - Epithelium is pseudo-stratified columnar with brush boarder - Tunica serosa that covers the surface is highly vascular

Question 97

What is the main thing used to synchronise cattle and how works

Answer 97

Progesterone and then PGF2alpha 7 days later - There are two groups in the cattle ones before ovulation and ones who have already ovulated - To bring them in synch need to do 2 things: 1. Give progesterone initially -> the animals that are about to ovulate stop them from ovulating 2. PGF2alpha 7 days later -> the animals that have ovulated and have corpus luteum accelerate luteolysis and shorten time to ovulation to catch up with the ones that are about to ovulate and have been stopped by the progesterone

Question 98

Define endometritis and metritis

Answer 98

Endometritis -> inflammation of the functional lining of the uterus (endometrium) Metritis -> inflammation of the wall of the uterus -> full thickness of the uterus

Question 99

What is the difference in terms of when occurs for endometritis/metritis in cattle and horses (which has which)

Answer 99

CATTLE - Generally occurs POST PARTUM ○ Open cervix, retained membranes, severe negative energy balance (everything they have into milk) - Breed cows back 80 days -> have time for the metritis to have resolved HORSE - POST MATING ENDOMETRITIS ○ Normal!!! For a little while but if maintained after 48 hours then have an issue § Sustained inflammation can be infectious but NOT ALWAYS -> sterile post mating endometritis (do to issues with the anti-inflammatory cytokines) - Breed horse back 10-21 days (after foal heat) -> less time to resolve the endometritis ○ ALWAYS BREED BEFORE OVULATION

Question 100

How to treat metritis in cattle

Answer 100

cattle - metritis - PGF2alpha -> some evidence of uterine contractions, gets rid of the corpus luteum with produces progesterone that is imunodepressant - Antibiotics -> get rid of the infection

Question 101

how to treat endometritis in horses

Answer 101

- PGF2alpha -> some evidence of uterine contractions, gets rid of the corpus luteum with produces progesterone that is imunodepressant - Antibiotics -> get rid of the infection

Question 102

what precautionary methods should be put in place for next breeding if a mare has endometritis

Answer 102

- Flush before service the mare - need to do within 30mins as otherwise will get inflammatory reaction to the saline - Flush with saline and give oxytocin -> at about 4 hours after mating (fluid should have left by now)

Question 103

what causes metritis in horses

Answer 103

- Post-partum due to retained foetal membranes - occurs within hours Retained foetal membranes

Question 104

what are the 2 main ways to induce ovulation in horse and which is best

Answer 104

1) Give hCG in late Oestrus to induce ovulation - BEST | 2) If give PGF2alpha in late dioestrus will just result in luteolysis but not ovulation for a few days so not used

Question 105

Dog pyometra what is it, when occurs, what most common cause and does it effect fertility

Answer 105

Pyometra -> infection of the uterus - Is a metritis - 6 weeks after heat - DIOESTRAL DISEASE - E.coli until proven otherwise (more than 95%) ○ May be predisposed or infection of bacteria ○ Infection generally due to long immune suppression resulting from long canine dioestrus and prolonged progesterone - Generally doesn't lead to infertility

Question 106

what are the 2 main treatments for dog with pyometra and which is best

Answer 106

- Spaying is the number one treatment option - Medically -> give PGF2alpha to induce contractions and removal of bacteria, also give antibiotics but not as important in PGF2alpha