🐮🐄🐃🐂 Flashcards
Breeding programs need to integrate
Theriogenology and Herd Health or Proventive Medicine
4 reproductive indices determine the efficiency of the dairy herd
1) VWP
2) estrous detection
3) conception rate
4) pregnancy loss
Pregnancy rate =
cows pregnant / # cows eligible to become pregnant in 21days
Why do we have VWP and how long is it?
Cow needs to return to its Pregravid state
1) uterine involution: reduces in size and re-epithilization of inter carbuncular endometrium
2) early onset of ovarian cyclicity for the resolution of uterine infections
3) recover from negative energy balance
- -> completed by 42days pp (or 4 weeks) but ideal is 70-80days pp
Synchronization of Estrus
- give PGF2 at day 14 and AI them at days 16-21
- PGF2 regresses CL, we only want CL after they become pregnant
OvSynch TAI Protocol
- give PGF2 at day 7
- give GnRH at day 9 (to ensure ovulation) and AI them after 16hrs
How many cows get pregnant after first breeding attempt?
55-75%
-> detect and breed rest of them as soon as possible
Pregnancy detection (cow)
- per rectum: 33-35 days
- ultrasound: 26-28days
- pregnancy specific protein B: 30days
Pregnancy Loss (cow)
- early embryonic death occurs before day 17 and is the largest degree of pregnancy loss
- late embryonic loss occurs from day 17-42
- abortion refers to loss after day 42 of gestation
Female Infertility (cow)
-sign, not a condition
-non infectious:
>anestrus: failure to detect (human error) or exhibit estrus (cow problem)
>true anestrus = follicle develops but fails so ovulate
What is the primary sign of estrus
Standing to be mounted
Checking for estrus (cow)
- boring
- needs to be done 2x day ideally
- can use the help of heat detection aids (pressure activated, tail chalk, collars, pedometer) or synchronization of estrus
- activity monitors keep track of laying time, rumination, laying bouts.
Normal follicle growth
- FSH recruits follicles
- selection of dominant follicle
- insulin and IGF1 from the liver together with LH pulses stimulate follicle to become preovulatory
- preovulatory follicle stimulates estradiol to give positive GnRH feedback -> more LH
- LH surge causes ovulation
Is there ovulation during negative energy balance ?
no !
-FSH is released but no LH is present (or is very low) so the follicle cannot grow
Cystic Follicular Degeneration
Failure of LH surge to occur: lack of progesterone priming of LH surge center in hypothalamus, low estrogen secretion from the developing follicle
- signs: frequent estrus, irregular estrus, or ANESTRUS (most common)
- diagnosis: anovulatory follicle, no CL, lack of uterine tone, flaccid uterus
Follicular and Luteal Cysts
- feel about the same in palpation
- luteal is due to no lutenization
- follicular is due to not enough LH to cause ovulation
- Treatment: NOT MANUAL RUPTURE, GnRH, PGF2 for luteal cysts, times AI
What is the most common ovarian tumor? (cow)
granulosa cell tumor
pyometra (cow)
infection of the uterus
-treat with PGF2
segmental aplasia
one horn is missing, but it still has ovaries so CL cannot regress
-treat with unilateral ovariectomy
natural service herd is dependent on:
healthy, breeding sound bulls
things to consider for bull selection
- 1 bull/25cows
- age, breed, type
- buy virgin bulls (better) at least 60days before breeding season
- good to breed at 15m
- give them time to adjust to ration and be quarantined
requirements for picking a bull
- physically sound + good health
- functional repro system
- strong libido and fertile spermatozoa
- free of venereal diseases
what has been observed in herds that introduced BSE?
5-10% increase in pregnancy percentages
BSE
1) identification / history
2) physical exam + body condition
3) reproductive examination
4) collection and examination of semen
