Breeding Mgmt In Swine- Ppt Flashcards
oocytes per estrus
15 to 30
Gilts reach puberty at
150 to 220 days old
4 factors that influence puberty onset
- nutrition
- season/lighting
- confinement
- boar exposure
Exposing boars to females causes increases in…
GnRh, LH and E2
What age should you expose gilts to boars
150-170 days
How long should boars be exposed to gilts
5 to 30 mins/day
____ contact is recommended between gilts and boars
Physical
What causes greater response to boar exposure
Combining w/ transportation stress @ 160 days
Best way to stimulate 1st heat
Combining boar exposure with transportation stress
Boar exposure and PG600 causes
More animals coming into heat 5-10 days after tx
(Can’t synchronize cycle)
During what cycle do you perform 1st AI
2nd or 3rd cycle
Pregnancy length
113-115 days (3 mos, 3 wks, 3 days)
Lactation anestrus
16-40 days in lactation
Weaning to estrus interval
4-6 days
Why are pigs rarely bred naturally?
Their body wt is too heavy
Estrous cycle length
18-24 days
Sows have ___ estrous cycles compared to gilts
Shorter
Estrous phase length
4-6 days
Luteal phase length
15 days
Estrus signs
- standing heat
- 6-12 mm follicles
Duration of estrus
- in presence of boar: 40-60 hrs
- varies <24 hrs to >96hrs in individual sows
Ovulation length
41-47 hrs after LH surge
Duration of estrus is varied by
- intensity of boar contact
- stress
- parity (shorter in gilts)
- weaning to estrous interval
Diestrus events
- CL reach final size a week after ovulation
- development of CL and P4 prod. Is independent from LH prod. Until 10-12 days
- PGF2a causes luteolysis at 15 days but CL responsive @ 12 days
Lactational anestrus
- LH suppressed bc of suckling induced inhibition of GnRH
Degree of LH suppression is related to
- suckling intensity
- negative energy balance of sow
- stress
Fertility improvement post weaningg
- pst weaning follicle regression: via progesterone analogue for at least 4 days or inseminating sows @ second estrous post-weaning
eCG
- Good of estrous and ovulation induction
- not available in US
hCG
Stimulate ovulation (not estrus)
PG 600 (400 eCG & 200 hCG)
- Induces puberty in gilts (must be at least 185 lbs and 5 mos old)
- > 55% gilts in estrus within 7 days of injection
- > 90% gilts ovulate w/ 12-15 follicles
Altrenogest (Matrix)
- synchronizes estrus in pubertaal cyclic females
- must be fed for at least 14 days
- fed individually
Triptorelin gel
- GnRH agonist
- give @ level of cervix & 22 hrs post AI
Estrous synch in prepubertal gilts
- PG600
- Boar exposure
- travel
- combination of above tx
Pubertal and cyclic gilt estrous synch
- progesterone
- PG600
- GnRH or hCG
- triptorelin
Weaned sows estrous synchronization
- based on weaning time
- check for heat 4-6 days post weaning
- triptorelin
2 sites to inseminate female
Cervix and uterine horn
