Reproductive Technologies Flashcards
1
Q
what are different reproductive technologies
A
- manipulation of the estrous cycle
- suppression of estrus
- artificial inseminationon
- in vitro fertilization
- intracytoplasmic sperm injection
- embryo transfer - oocyte transfer + gamete intrafallopian transfer
2
Q
why would you manipulate the strous cycle
A
- because mating happens out of season
- early season breeding = we can induce this with light commencing in december with GnRH
can also be reFSh or rsLH
3
Q
how can you control ovulation time
A
- to time mating or insemination
- length of estrus is variable
- occurrence of ovulation not predictable
4
Q
what helps to stimulate ovulation
A
- hCG = inseminate 24 hours post treatment
- ovulation within 48 hours
- mimics LH
5
Q
what causes foal heat
A
- 5-15 days post parturition
6
Q
how can you delay foal heat
A
- must be done 12 hours after foaling
- progesterone or altrenogest
- treat for 8 days
- estrus 3 days later
- ovulation 5 days after estrous
7
Q
what does exogenous PGF2a do
A
treat infertility due to spontaneously prolonged corpus luteum
- induce ovulatory estrus after foal heat
- shortens length of diestrus
- induce abortion
8
Q
reasons for estrus suppression
A
- GnRH immunization
2x 4 weeks apart - ovarian activity suppressed 4 weeks after 2nd injection
- supression is good for over 23 weeks
9
Q
other ways to suppress estrus
A
- daily administration or slow release formulation od synthetic progestin (alternogest)
- daily d7 to d14 post ovulation administration of oxytocin (2-3 months suppression)
- marbles - conceptus ablation
- self assembling intrauterine device
10
Q
what is AI
A
- insertion tube with semen in it into the mares uterous
- 1st cycle pregnancy rates
- cooled (65% success)
- frozen (56% survival rate )
- fresh (76%)
11
Q
what are the different types of AI
A
- deep horn insemination
- hysteroscopic insemination
12
Q
what do you evaluate semen on
A
- motility
- percent abnormalities
- radial oxidative stress
- total antioxidant capacity
- DNA fragmentation
- membrane status
- capacitation-like status
13
Q
what is in vitro fertilization
A
- oocyte recovery - flushing or surgical collection
- harvest immature oocytes
- oocytes matured in vitro (50%) viable
- sucess rate is low (some success made possible by ICSI)
14
Q
what is ICSI
A
- single sperm injected directly into egg
- porduce foals from infertile stallions
- low success rate
- provide in vitro produced embryos for further study or freezing
15
Q
embryo transfer
A
- 35 000 reported in 2020
- foals from mares in competition
- more foals per mare
foals from mares unable to maintain pregnancy
