Lecture 2: Bovine Infertility (Risco) Flashcards
infertility = sterility ?
NO.
T/F: infertility is a sign, not a specific condition
T
T/F: there are both infectious and non-infectious causes of infertility
T
estrus vs. estrous
estrus: a noun “a cow displays estrus”
estrous: an adj. “the estrous cycle”
most common form of infertility
non-infectious (esp. due to lack of detection of estrus)
main causes of non-infectious infertility
cow is in anestrus due to failure to detect estrus** or failure to exhibit estrus. If the latter occurs, the cow is in true anestrus and something is likely actually wrong with the cow.
1ary sign of estrus
standing to be mounted
methods to help improve detection of estrus
- heat detection aids
- synchronization of estrus or ovulation (i.e. using Ovsynch protocol or PGF2a)
Heat detection aids
- Pressure activated device
- Tail chalks/paints
- Pressure detector (heatwatch) -detects when cow being mounted
- Activity monitoring systems (accelerometer, pedometer, collar)
detection of cows displaying estrus (AI submission rate) determines:
when cows are first bred at the end of the VWP
activity monitors measure:
- activity
- laying bouts
- laying time
- rumination
example of a heat detection aid
HeatWatch II system. When cow mounts another cow, it triggers a sensor which alerts a computer of the event
Ovsynch TAI Protocol
(ovulation occurs before d0) d0: give GnRH d7: give prostaglandin d9: give GnRH d10 (16 hours post-GnRH): TAI (Timed Artificial Insemination)
How to synchronize estrus for AI (not Ovsync)
d0: give PG
d14: give PG again
d16-21: AI
Describe how Progesterone (P4) lvls change throughout OvSync protocol
At ovulation (before d0), progesterone starts at a very low level then steadily increases before plateauing around 7 ng/ml just before d0, when GnRH is given. Plateau continues until d7, when PG is given. P4 then drops off to a negligible level around d8.5. GnRH given again at d9 and then TAI started at d10. (See slide 15)
When do follicular waves occur in Ovsync?
First wave starts at ovulation when P4 is increasing before d0. Second wave starts around d2-3 and ends after d10 when TAI is occuring.
Presynch-Ovsynch protocol
d0: PGF
d14: PGF
d26: GnRH
d33: PGF
d35: GnRH
d36: TAI