cow fertility and repro Flashcards
What does a normal follicle look like?
transient, soft
1.5 - 2cm in oestrus
What does a vacuolated CL look like?
same size as normal CL
vacuole disappears during pregnancy
how does a lutenised follicle appear?
over 2.5 cm
large vacuole
from anovulatory mature follicles
occur early postpartum
how does a follicular cyst appear?
thin walled oestradiol secreting over 2.5 cm single / multiple / uni/bi lateral causes subfertility
how does a luteal cyst appear?
thick walled over 2.5cm P4 secreting single cause subfertility
how does an inactive cyst appear?
thin walled
inactive
single / multiple / uni / bi lateral
result of sub-fertility
What can cause no observed puberty in the heifer?
- ovarian aplasia and hypoplasia
- freemartinism
How do you diagnose a freemartin?
test tube - how far does it go in (only 5 cm = +ve)
karyotyping
Causes of no observed oestrus in a cow?
- anoestrus / acyclicity (high yield, low energy, poor BCS, stress)
- ovarian cysts
- persistent CL
- suboestrus
- failure to detect oestrus
how does poor energy intake cause anoestrus?
poor energy intake = low IGF1 with decreases GnRH, embryo growth, ovary steroidgenesis and luteal activity
what is found on a clinical exam with a cow with anoestrus?
- smooth and flat ovaries
- small follicles, no CL
- milk p4 stays low
How can you treat anoestrus / acyclicity?
- get back into +ve energy balance
- improve nutrition
- GnRH
- CIDR / PRID
What causes ovarian cysts?
- anovulatory grafiaan follicle where the granulosa cell layer degenerates so the cow become acyclic or nyphomaniacal
- failure of LH surge
- few LH receptors in granulosa cells of cysts
How do you treat ovarian cysts?
- dont rupture
- luteal - PGF2a
- Follicular GnRH then PGF2a or CIDR / PRID
what is the problem with a persistent cL?
pyometra interferes with leutolysis
How do you treat a persistent CL?
PGF2a
What can cause suboestrus?
non cow friendly environment
What are the signs of oestrus?
restless not eating low milk searching for other cows mounting / standing group bellowing clear vulval elastic mucus discharge
What are the causes of failure to detect oestrus?
- cow oestrus
- person problem
How could you overcome poor oestrus detection?
- put a bull in
- ovsynch
- synchronise herd
- heat mount detectors
- measure milk p4
What can cause return to oestrus after service?
- not calving
- anovulation
- delayed ovulation
- incorrect AI timing
- hormonal imbalance
- structural defects
- infection
- nutritional imbalance
- stress
cow embryopathic organisms
campylobacter fetus tritrichomonas fetus mycoplasma BVDV IBR chlamydia
what is a regular return to oestrus?
return to oestrus 18-24 d after AI
what is an irregular return
return to oestrus 24 d
what does it mean if sum of 2 consecutive returns is about 42 d?
AI timing incorrect
what is a cow a repeat breeder?
returned on 3/4 consecutive occasions
what does abnormal vulval discharge indicate?
endometritis / metritis
what are causes of endometritis / metritis?
-long or short gestation retain membranes parity yield dystocia and trauma hygiene nutrition repeat breeder
how do you treat endometritis?
- CL present = PGF2a
- no CL = intrauterine cephalosporin
- chronic = peridine iodine
how is an abortion classified?
<271 d dead / alive for less than 24 hr
non infectious causes of abortion and stillbirth
genetic endocrine toxins heat stress iatrogenic dystocia
infectious causes of abortion and stillbirth
truperella pyogenes leptospira bacillus BVDV neospora e.coli strep fungi
what is the voluntary waiting period? what can extend it?
- management decision for earliest service date (when she starts cycling)
- extended by dystocia, metabolic problems, disease
- normally 42 d
what is the calving - 1st service interval? and what affects it?
- normally 65 d (ESD +21)
- affected by VWP , postpartum problems, return to cyclicity, poor oestrus detection
what is the first service submission rate?
proportion of cows served within 3 weeks of ESD, aim ~ 85 %
why do we measure first service submission rate instead of calving - s1?
- calving to s1 is affected by cows not served, unusual VWP and any late / early cows cancel out
what is the aim for calving to conception interval?
85 d
what is the aim for the calving interval?
365 d
what will milk p4 be during oestrus
<5ng/ml
how can we look at how well conception is on a graphical form?
q/cu - sum graph
- move one box up if conceived and one down if didnt
- plot on x axis calf number and date of AI
- can see what hapenned on what days
what animals would you examine on a routine visit?
- problem animals
- post calving / pre breeding
- irregular returns
- oestrus not observed
- PD
- pregnant
- odd events
What is a good conception rate?
~ 60%
if see bulling which cow do you AI now?
- cow on bottom
- cow on top keep an eye on as coming into heat soon
how many joules is one calorie?
4.2 j
how many mJ / L of milk?
5mj/l of milk
how much extra energy do high activity cows need?
19mj / day
how much extra energy is needed for the first 2 months of pregnancy?
0.5 m j /day
how much extra energy is needed for month 4 of pregnancy?
1.6 mj / day
how much extra energy is needed for month 6 of pregnancy?
5.0 mj / day
how much extra energy is needed at full term ?
35 mj/day
how much extra energy is needed for an overdue calf?
44 mj / day
how much energy is mobilised by 1 kg weight loss?
35 mj
what 2 factors decrease voluntary feed intake?
around calving
fat cows
what are high protein sources of food?
protein meal
fishmeal
NPN
what are moderate protein sources?
alfalfa
legume
what are low protein sources?
grass hay
cereals
straw
when is pregnancy toxaemia most commonly seen in cattle?
thin, twin, beef cattle
how can you prevent pregnancy toxaemia?
dry off at BCS 3 and calve at 3
what is normal fat metabolism around calving?
around calving get a normal mobilisation of fat so increase FA in blood is normally dealt with by the lvier
what causes fatty liver disease?
fat dry cow dry cow on a diet fat cow at calving not eating dry cow having sudden diet change excessive weight loss post partum
what can be the consequences of fatty liver disease?
immunosuppression retained foetal membranes endometritis infertility ketosis mastitis
what are the 9 ways to PD?
1) non return to oestrus
2) ultrasound from 30 d transrectal
3) milk and plasma p4
4) membrane slip from 35 d
5) disparity in horn size from 35 d
6) plapation of foetus 45-60 d
7) presence of placentomes from 80d
8) fremitus of middle uterine artery from 85 d
9) oestrone sulphate in milk and plasma from 105 d
how can milk and plasma p4 predict pregnancy?
during oestrus p4 should drop
if it doesnt then pregnant of luteinised cyst or persistent CL, incorrect AI timing
if low then def not preg
what can cause a false positive in horn size disparity?
incomplete involution
fluid
pus mucous
what is fremitus in the uterine artery?
hypertrophy of the artery (middle uterine artery) in the broad ligament
can feel increased turbulence of blood flow
what can oestrone sulphate tell you?
only present after d 105 if there is a live foetus
produced by foeto-placental unit and conjugated to sulphage
What is the difference in early and late embryonic mortality?
early is before maternal recognition and late is after
early you get a regular return to oestrus, late you get an irregular return
what day does embryonic loss become foetal loss?
d 42
How can BCS affect pregnancy rate?
if low 5w post partum then get lower conception rates
what are 4 common pregnancy complications?
1) hydrops
2) uterine torsion
3) cervical vaginal prolapse
4) uterine prolapse
what are the two types of hydrops that can cause pregnancy complications?
- placental oedema
- foetus
what can you do with a cow with placental hydrops?
- normally in last 3 m
- cull
- induce parturition
- drain fluid and C section
what are the types of foetal hydrops and what can you do?
- hydrocephalus, ascites, anasarca (inside out)
- fetotomy, C section
How do you diagnose and what can you do about uterine torsion?
diagnose by vaginal and rectal exam
reposition internally or externally
what can predispose to cervical / vaginal prolapse?
- high / low BCS
- high roughage diet
- twins
- high oestrogens
- lack of exercise
- urinary retention
- breed
- age
what can be the consequences of cervical vaginal prolapse?
infection
inappetance
urinary retention
rupture and guts out
what can you do to treat a cervical vaginal prolapse?
analgesia
epidural
spoon / harness
sutures shut
what do you do with a uterine prolapse?
remove foetal memebranes epidural block put in frog position keep pushing (all the way in, use a bottle) calcium borogluconate relieve ruminal tympany
what is eutocia?
normal parturition
what is prodrome?
stage 1 labour foetal positioning cervix dilation foetal membranes exposed behaviour
what is puerperium?
recovery of genital tract post partum
what are the 2 categories of maternal dystocia cuases?
expulsion
birth canal
what is the category of foetal dystocia causes?
disposition
what are the maternal expulsion causes of dystocia?
uterine inertia
defective / inadequate straining
what are the maternal birth canal causes of dystocia?
failure of cervix, soft tissues or ligaments to relax
uterine torsion
what are the maternal and foetal components of foetal maternal disproportion?
maternal - inadequate pelvic diameter
foetal - too large
what are the foetal disposition causes of dystocia?
abnormal presentation
position
posture
if calf presenting normally and carpal joint is 10 cm out how much force is needed?
2 people pulling
if double muscled calf how much force is needed
1 person pulling only
what do you do once the head is out to get the hips to fit?
rotate 90 degress and pull dorsally so hips fit
what are the 3 aids
chains
head snare
hooks in eyes
if presenting caudally and hock is 10 cm out how much force is needed?
2 people pulling
which way do you pull a normal vs caudal presenting calf?
normal - pull downwards
caudal- pull dorsally
what is foetal presentation? and what are the 3 types
relationship between longitudinal axis of dam and baby
longitudinal anterior
longitudinal posterior
transverse
what is foetal position and what are the 3 types?
relationship between dorsal foetus and top of canal
dorsal
ventral
lateral
what is foetal postures and what are the 3 types?
disposition of foetal appendages
limb flexions
neck flexions
head displacements
what is the normal postures, presentation and position of a calf?
normal posture, dorsal position, longitudinal anterior presentation
what are some causes for foetal disposition?
weak uterine contraction oversized calf delayed development of foetal reflexes weak foetal movements competition for uterine space ankylosis of joints
What is the normal process of involution?
shift from hypertrophy to atrophy
reduction in size of myofibrils
influenced by prostaglandins and oxytocin
What happens to the uterus during involution?
greatest decreased in first few days
by 8-10d uterus should all be palpable per rectum
normal by 26-50 d
what happens to the cervix during involution
after 96 h only 2 fingers can fit
normally at 25d the diameter of the cervix should exceed that of the previously gravid horn
back to normal in 60 d
how does the endometrium regenerate post partum?
- Caruncles - degenerate, become necrotic as ischaemic and slough off
- Lochial discharge - sloughed necrotic material, blood, foetal fluids, for 2-9 d pp, yellow/reddish brown, no odour, 0.5 - 2l
How are contaminants eliminated post partum?
phagocytosis by migrating leucocytes, physical expulsion by uterine contractions and secretions
sterile within 8-9 w
How does cyclical activity resume post partum?
- during pregnancy P4 feeds back on the pituitary so it becomes regractory to GnRH pp
- after 7-10 d get FSH surge and a follicular wave in the opposite horn to the pregnancy and will only ovulate if follicle makes enough oestradiol
- often gets a shorter luteal due to poor follicle development so an inadequate CL
- this is delayed by suckling
what are 4 factors that can disrupt any events of the puerperium?
dystocia / Caesar
uterine prolapse
retained foetal membranes
uterine disease
what are the 4 normal processes in puerperium?
involution
regeneration of the endometrium
elimination of contaminants
resumption of ovarian cyclical activity
How can dystocia / caesar disrupt puerperium events?
- break host defences
- physical deformity and tissue damage to vulva and cervix so more prone to contaminants
- uterine inertia so cant expel contaminants
how can a uterine prolapse disrupt puerperium events?
can increase conception times
why does a uterus prolapse?
straining in stage 3
flaccid uterus
gravity
what are the risk factors fro a uterine prolapse?
pluriparous
increased parturition time
compromised tone
increased abdominal straining
why do retained foetal memebranes affect puerperium events?
predispose to uterin inf and infertility
why do you get retained foetal memebranes?
failure of placental maturation
failure of detachment
inadequate uterine contraction
how do you treat retained foetal membranes
wait 5 d for a vet
can try gentle traction
dont use abx as want it to putrefy
collagenases in umbilical a
what are the risk factors for retained foetal membranes?
dystocia premature abortion stillbirth multiples infectious placentitis hypocalcaemia hydrallantois old prolonged gestation micronutritent deficiences
How does the placenta normally mature and detach?
- changes in P4 and E2 conc
- changes in collagenases and proteases
- change in number of binucleate cells in trophoectoderm
- distortion of placentomes
what are the risk factors for uterine disease pp?
dystocia
RFM
high pathogen load
acyclic (as e2 nd p4 needed for local immune system)
what are the signs and how do you treat endometritis?
signs - mucopurulent discharge, systemically find, neutrophils in uterine luminal fluid, poorly involuted uterus
treat - stimulate oestrus ( cyclic - PGF2a, non - GnRH), intrauterine cephairin
what are the signs and how do you treat metritis?
signs - systemically ill, dull, low yield, low appetite, toxaemia, purulent fetid fluid, distended atonic uterus, sore swollena dn inflamed vagina and vulva
treat - stabilise, Abx bacteriocidal as have endotoxaemia, uterine lavage and oxyteracycline
what are the signs and treatment for pyometra?
signs - acyclic, purulent material, persistent CL, large and distended horns with a closed cervix
treat - PGF2a and intrauterine cephapirin
what are the signs of free martinism?
blind ending vagina no apparant cervix streaky structures where the ovary is normally acyclic no sings of heat oestradiol very low progesterone low no effect from hCG or eCG prominent clitoris
how can you detect the y chromosome in free martins?
- PCR with probes for y-chromosome specific segments
how do we get free martins?
- xx and xy twins
- share blood supply so female exposed to male hormones
- they have testosterone so the wolfian duct differentiates
- mullerian ducts dont form properly so blind ending vagina
what can you use free martins for?
beef
research
oestrus detection
how does normal XY develop?
1) SRY (sex determining region of Y) signals to testis formation
2) testis make testosterone
3) testosterone acts on mesonephric duct to form male internal genitalia
4) testosterone converted to 5-dihydrotestosterone by genital tubercle and 5 alpha reductase - acts on genital tubercle to make glans penis and scrotum
5) AMH from the testis acts on the mullerian duct so they dont differentiate
how is XX development different from XY?
1) no SRY so no testis form so get ovaries
2) dont need anything from gonads
3) no androgen from ovaries so not differentiation of wollfian duct
4) no AMH so paramesonephric duct (mullerian duct) becomes the uterus, oviduct and cranial vagina)
