Infertility in farmed species workshop Flashcards
List 3 ways that infertility presents in farm animals
Animals that are not (or do not appear to be) cycling at all
Animals are cycling but do not conceive
Animals that conceive but do not maintain pregnancy
If Animals that are not (or do not appear to be) cycling at all
describe how to investigate
Rule out poor oestrus detection first (i.e. are these animals truly in anoestrus) –> data and clinical exam
Investigate possible reasons for true anoestrus
If animals are cycling but do not conceive
describe how to investigate
Investigate reasons for non-conception including the male animal or AI procedure
If Animals that conceive but do not maintain pregnancy
Describe how to investigate
Investigate reasons for foetal/embryonic death
List 6 possible reasons for anoestrus in farm animals
failure to observe oestrus
metabolic/ nutritional
uterine infection
pregnancy
cystic ovarian disease
suckling calf at foot
In sheep are infectious or non-infectious causes of infertility most important in sheep
infectious
are infectious or non-infectious causes of infertility most important in cattle
non-infectious
how does BVD affect fertility
causes Early embryonic death (EED) and Ovarian damage
causes long returns to service and reduce conception rates
How does Border disease presentes regarding fertility in sheep
increased barren rate
List 3 possible viral causes of infertility in farm species
BVD- cattle
Border disease- sheep and goats
IBR- cows
List 4 bacterial and protozoal causes of infertility in farm species
Leptospira - cattle (sheep can act as carriers)
Brucella - all ruminants
Campylobacter - cattle and sheep
Tritrichomonas- cattle
What are the effects of brucella
poor fertility
epididymitis and orchitis
How does IBR effect reproductive performance
temporary ovarian necrosis
follicular degeneration
List 2 special considerations you need to make for maiden heifer when investigating fertility
may not have reached puberty
may have repro tract abnormalities- e.g. freemartinism or Mucometra (rare)
List 4 possible effects of campylobacter on the repro tract in cattle/ sheep
Endometritis (cattle)
Failure to conceive
Early embryonic death (cattle)
Abortion (sheep and cattle)
Before giving PGF2a to a cow what should you do
check for pregnancy
what effect does GnRH have at start of oestrus
ovulation in 24-48hrs
what effect does GnRH have 10-12 days post-oestrus
reinforce CL action - aids progesterone secretion
Induce ovulation
Anti-luteolytic effects- makes CL less sensitive to PGF2a
List 4 possible uses of GnRH
synch protocols
Treat follicular cysts
Treat anoestrus cows
Ovulation in repeat breeder cows
List 6 possible causes of ‘ cycling cows that do not conceive’
improper/ incorrect insemination
infectious causes
toxins
metabolic/ nutritional cauases
iatrogenic causes- improper use of hormonal drugs
Sire choice
How does PGF2a work
Cause luteolysis of CL –> fall in progesterone resulting in FSH and LH release
Only work if CL present
at what point is a CL sensitive to PGF2a
CL only sensitive to PGF2α between days 5 – 15 of cycle
>17mm diameter on US scan
List 5 potential uses of PGF2a
Synch protocols
Treat luteal cysts
Induce abortion or parturition
Treat pyometra
Control of breeding and oestrus timing
Describe how progesterone works
Acts as an exogenous CL –> release progesterone and suppress GnRH release
Dominant follicle develops —> does not ovulate
Removal of device (drop in progesterone) –> LH surge —> ovulation
List 5 potential uses of progesterone devices
Synch and embryo transfer protocols
Treat cysts
Improvements in oocyte quality
Reduce time to service (seasonal herds)
Repeat breeders
Describe how to treat endometritis in cattle
PGF2a - may need 2 doses
possibly wash out ???- day after PGF2a when cervix opens - variable results
Recheck on next visit
Describe how to treat follicular cysts in cows
GnRH or progesterone
Can pop them- but this is risky - there are reports of some animals getting life threatening bleeds and formation of scar tissue that can affect ovary function
Describe how to tell the difference between follicular and luteal cysts
Luteal cysts= the wall of the cyst is 4-5mm thick, made of luteal tissue so same echogenicity as a CL
Follicular cyst= thin wall
Describe how to treat multiple small follicles
GnRH or progesterone- could be part of a synch protocol
what 2 things can multiple small follicles on both ovaries mean
the animal ovulated yesterday
OR
is in true anoestrus
What is the calculation to work out fertility efficiency
submission rate x conception rate
List 4 ways to improve oestrus detection in cattle
improve staffing
improved environment
oestrus detection aids
synchronisation protocols
List some examples of oestrus detection aids
cow worn devices
tail chalk - when rubbed off = has been mounted
Heat patch- change to red is mounted for >3s
List 3 ways to make a bull infertile
vasectomy
epididymectomy
penile alterations- for venereal diseases- mostly done in US
What are the effects of leptospira on reproduction
poor fertility and early embryonic death –> may be due to endometrial inflammation
can sheep become infected with leptospira
yes but they rarely show disease- they are usually carriers
What are the effects of tritrichomonas on reproduction
early embryonic death
pyometra
endometritis
Describe how we can tell the difference between metritis and pyometra (endometritis)
pyometra will have a CL
metritis occurs shortly after parturition- cow systemically unwell
what size are follicular cysts
over 25mm
what does ineffective oestrus detection lead to
a low submission rate and subsequent low fertility efficiency
what is the submission rate calculation
(number of cows actually bred / number of cows eligible to be bred ) x100
