Porcine Breeding Management Flashcards
Average estrus cycle length of sow
21 d
SINGLE FOLLICLE WAVE (With multiple follicles rupture over a 1-4 h period)
Estrus is gilts vs. sows
Gilts: estrus 36-48 h
Sows: estrus 48-72 h
In swine Ovulation occurs _____ of the way through estrus or _____ h after the LH peak
2/3 (36 h average) through estrus
24h after LH peak
Multiple follicles rupture over a 1-4 h period
Age of puberty in swine
5-8 months
depends on:
Genetic composition
Environmental factors: season, social environment, nutrition
Most are capable of expressing estrus ~165 days of age
Puberty in swine may be delayed by…
Housing in small (<3) or large (>30) groups
Constant elevated ambient temperature
Poor air quality
Advancing Puberty in Non-Cycling Gilts
Boar exposure
Exposure between 150 and 170 days most effective for advancing age at puberty and results in highest degree of estrus synchrony
Direct contact (5-30 min.) with females
Mature boar – olfactory, auditory + visual stimuli
*Improved response when combined with transportation stress
Effects evident by 30 days after initiation
Relocation/movement
Mix groups of females – induce puberty + estrus
PG600® (400 IU PMSG + 200 IU hCG)
Should be >165 days of age and 185 lbs
Induce estrus in >55% of gilts within 7 days
PMSG ~ FSH; hCG ~ LH
Estrus Synchronization and Induction in swine
All-in/All-out strategies for weaning
Group weaning after 21-day lactation
Estrus occurs within 4-7 d
Increase % of sows returning in 7 days with PG600 administration
Heat stress (season), nutritional intake, parity most commonly affect wean-to-estrus interval and increase nonproductive sow days
Common factors that affect wean-to-estrus interval and increase nonproductive sow days
Heat stress (season), nutritional intake, parity
Synthetic Progestogens in swine
Altrenogest (Matrix®)
Feed at a rate of 15-20 mg/hd/day for 14 d
Approved for use in pigs in the US (21 day withdrawal time before shipment)
Mix the dose in 1 lb. of the ration and then feed the remaining diet
Females show signs of estrus 4-7 d after withdrawal
Concerns of Using Synthetic Progestogens in swine
Underdosing/underfeeding
-Cystic ovarian disease
-Failure to cycle
-Variable farrowing rates and litter sizes
Public health
Avoid skin contact/ wear gloves
Possible side effects to women
In swine cystic ovarian disease is a concern for the use of synthetic ____________ for cycle management
Progestogens (Altrenogest (Matrix®)
Cannot truly “short cycle” pigs with….
PGF2a
Do not respond until day 12 (cows-day 5)
so would only be saving 3-4 days
Can be used if accidental exposure to boar but not useful in cycle management
In swine there is lysis of CL after day…
12 of the cycle (PGF2a not helpful for management of cycle)
Prostaglandin use in swine
Administer 14 days after boar exposure
Many producers will use this to terminate pregnant females and put them in another breeding group = not best method!!
Cannot truly “short cycle” pigs with PGF
Lysis of CL AFTER DAY 12 of cycle!
Only save ~3-4 days before natural luteolysis occurs
Little to no PGF receptors before
Affects ability to terminate unwanted pregnancies
Estrus signs in swine
Red, swollen vulva
Mucous discharge
Restless
Frequent urination
Increased vocalization
Mounting females
Elevation of ears, locking knees, and elevating back (lordosis response)
