Porcine Flashcards
What is a stag?
Male castrated after puberty
What is a barrow?
Male castrated before puberty
What are 2 methods of castration?
Surgical
Immunological - Impravac GnRH vaccine
What is gestation length?
114-116d
What is the production aims for litters and pigs weaned/sow/year?
- 2 litters
10. 8 pigs weaned
What type of uterus do Sows have?
Bicornuate with highly developed uterine horns
How is the oestrus cycle described?
Non-seasonally polyoestrus
What type of ovulators are pigs?
Spontaneous
How long is the oestrus cycle?
21 days
When does puberty occur in sows?
5.5 months
What cycle are gilts first bred on?
3rd cycle
How many follicles undergo atresia?
40%
How long does proestrus last?
4-6 days
How long does oestrus last?
1-4 days
What hormone is not as significant in pigs as in polyovular species?
Inhibin
How long is dioestrus?
14 days
When does progesterone begin to rise?
2-4d after oestrus
Is the developing CL dependent on LH?
Not at the start
Until when is the CL resistant to PGF2a?
Until after day 12 of dioestrus -> maternal recognition of pregnancy occurs here (luteolysis will not occur and conceptus produces oestrogen)
What is the role of oestrogen produced by the conceptus?
To re-route PGF2a into the uterine lumen rather than circulation -> prevents luteolysis
How many piglets are required for MRP?
2 per horn
What type of placentation do pigs have?
Epitheliochorial diffuse (like horses)
2 methods of heat detection
- Expose to 10 mins boar contact daily
2. Back pressure test
when should we mate pigs?
24 hours before or 4 hours post ovulation for >90% conception