Bovine Infertility

Question 1

bovine infertility (females)

Answer 1

• infertility is a sign, not a specific condition
• non-infectious and infectious causes

Question 2

non-infectious infertility

Answer 2

• 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

Question 3

estrus detection

Answer 3

• 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

Question 4

estrus vs estrous

Answer 4

estrus-noun

estrous-adjective

Question 5

heat detection aids

Answer 5

• pressure activated device
• tail chalks/paints
• pressure detector
• activity monitoring systems-accelerometer
  
  • pedometer or collar
  • increased activity when in heat

Question 6

why is detecting cows in estrus important?

Answer 6

AI submission rate

determines when cows are first bred at end of VWP

Question 7

synchronization of estrus timeline

Answer 7

day 0 = PGF_2alpha

day 14 = PGF_2alpha

day 16-21 = AI

Question 8

OvSynch TAI protocol

Answer 8

• best method for heat detection

day 0 = GnRH

day 7 = PGF_2alpha

day 9 = GnRH

day 10 (16 hrs) = TAI

Question 9

Presynch-Ovsynch

Answer 9

day 0 = PGF

day 14 = PGF

day 26 = GnRH

day 33 = PGF

day 35 = GnRH

day 36 = TAI

Question 10

true anestrus

Answer 10

• failure to exhibit estrus
• causes:
  
  • poor nutrition, poor BCS, disease
  • cystic ovaries or tumors
  • endometritis/pyometra
  • congenital defect
  • pregnancy
  • heat stress
  • rBST

Question 11

resumption of ovarian activity postpartum depends on:

Answer 11

• degree and duration of negative energy balance postpartum
• cows will only ovulate past the nadir (lowest point?) of NEB

Question 12

possible fates of dominiant follicle of first wave:

Answer 12

• ovulates (50%)
• does not ovulate (~25%)
• becomes cystic (~25%)
  
  • follicular or luteal

Question 13

follicular cysts

Answer 13

• follicle that fails to ovulate
• produce enough estrogen, but there is no GnRH surge

Question 14

luteal cysts

Answer 14

• some GnRH and LH release, but still doesn’t ovulate
• has a “crown”

Question 15

what is the main causes of cysts?

Answer 15

negative energy balance

Question 16

clinical signs of cystic follicular degeneration

Answer 16

• frequent estrus
• irregular estrous cycles
• anestrus

Question 17

dx of cystic follicular degeneration

Answer 17

• anovulatory follicle(s) >25 mm
• no CL
• check twice 10 d apart
• lack of uterine tone
• flaccid uterus

Question 18

tx of cystic follicular degeneration

Answer 18

• Ovsynch protocol = best tx​
• GnRH
• PGF_2a (luteal cyst)
• progesterone-not used anymore

NO MANUAL RUPTURE!

Question 19

ovarian tumors

Answer 19

• granulosa cell tumor- most common

Question 20

pyometra

Answer 20

• 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>}

Question 21

segmental aplasia

Answer 21

• segmental aplasia of the tubular tract derived from Mullerian duct system
• “white heifer disease”
• tx: unilateral ovariectomy

Question 22

infectious causes of infertility

Answer 22

• viruses
• bacteria
• calving related problems that lead to
  
  • metritis
  • mastitis
• depends on stress and level of exposure
  
  • herd immunity drops below disease pressure = disease

Question 23

vaccination program

Answer 23

• 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

Question 24

at what point during the calving period is a cow most susceptible to disease?

Answer 24

• 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