Bovine Infertility Flashcards
bovine infertility (females)
- infertility is a sign, not a specific condition
- non-infectious and infectious causes
non-infectious infertility
-
anestrus
- failure to detect estrus (human error)
- failur to exhibit estrus (true anestrus)
-
failure to detect estrus
- cow is normal
-
failure to exhibit estrus
- something is affecting cow
estrus detection
-
standing to be mounted is primary sign of estrus
- checking for this is time consuming/boring
- done every day-ideally 2x
- solutions:
- heat detection aids
- synchronization of estrus or ovulation
estrus vs estrous
estrus-noun
estrous-adjective
heat detection aids
- pressure activated device
- tail chalks/paints
- pressure detector
-
activity monitoring systems-accelerometer
- pedometer or collar
- increased activity when in heat
why is detecting cows in estrus important?
AI submission rate
determines when cows are first bred at end of VWP
synchronization of estrus timeline
day 0 = PGF2alpha
day 14 = PGF2alpha
day 16-21 = AI
OvSynch TAI protocol
- best method for heat detection
day 0 = GnRH
day 7 = PGF2alpha
day 9 = GnRH
day 10 (16 hrs) = TAI
Presynch-Ovsynch
day 0 = PGF
day 14 = PGF
day 26 = GnRH
day 33 = PGF
day 35 = GnRH
day 36 = TAI
true anestrus
- failure to exhibit estrus
-
causes:
- poor nutrition, poor BCS, disease
- cystic ovaries or tumors
- endometritis/pyometra
- congenital defect
- pregnancy
- heat stress
- rBST
resumption of ovarian activity postpartum depends on:
- degree and duration of negative energy balance postpartum
- cows will only ovulate past the nadir (lowest point?) of NEB
possible fates of dominiant follicle of first wave:
- ovulates (50%)
- does not ovulate (~25%)
- becomes cystic (~25%)
- follicular or luteal
follicular cysts
- follicle that fails to ovulate
- produce enough estrogen, but there is no GnRH surge
luteal cysts
- some GnRH and LH release, but still doesn’t ovulate
- has a “crown”
what is the main causes of cysts?
negative energy balance
clinical signs of cystic follicular degeneration
- frequent estrus
- irregular estrous cycles
- anestrus
dx of cystic follicular degeneration
- anovulatory follicle(s) >25 mm
- no CL
- check twice 10 d apart
- lack of uterine tone
- flaccid uterus
tx of cystic follicular degeneration
- Ovsynch protocol = best tx
- GnRH
- PGF2a (luteal cyst)
- progesterone-not used anymore
NO MANUAL RUPTURE!
ovarian tumors
- granulosa cell tumor- most common
pyometra
- purulent exudate contained in the uterine horn
- no positive signs of pregnancy
- persistant CL (PGE instead, immuno-suppressive)
-
culture:
- T. pyogenes, Fusobacterium, Bacterioides
- tx: PGF<strong>2a</strong>
segmental aplasia
- segmental aplasia of the tubular tract derived from Mullerian duct system
- “white heifer disease”
- tx: unilateral ovariectomy
infectious causes of infertility
- viruses
- bacteria
-
calving related problems that lead to
- metritis
- mastitis
- depends on stress and level of exposure
- herd immunity drops below disease pressure = disease
vaccination program
- minimum vax program should include 4 major viral disease
- BVDV (type 1 and 2)
- herpes virus
- respiratory syncytial
- also:
- Lepto, Clostridia, core endotoxin vaccines, others according to region
at what point during the calving period is a cow most susceptible to disease?
- first 21 days after calving:
- important for early dx, tx and control of diseases
- maintain BCS
- 21 days before and after-transition period for nutrition
