cow fertility and repro Flashcards
(125 cards)
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