Procine reproduction Flashcards
boar anatomy
fibroelastic penis
corkscrew shaped glans
prepucial diverticulum (pocket in prepuce)
caudally oriented testes- UNIQUE, not well protected so have well developed thermoregulators
boar accessory sex glands
vesicular gland, prostate gland, bulbourethral gland
NO ampulla
bull has sigmoid flexure (like bull)
seminal plasma
non-cellular fraction of ejaculate
secretions from the testis, epididymis, and accessory sex glands
semen
seminal plasma + sperm
accessory sex glands
secrete a large part of seminal plasma rich in ions, anti-oxidants and nutrients
the bulbourethral gland (Cowper’s gland): produce a whitish viscid mucus-like lubricating to form the gel plug
the sow anatomy
bicornuate uterus- 2 horns (very large) because polytocous species (litter bearing)
paired ovaries
red corpora lutea (plural because more than one), called red because not yellow in pigs like typical CL
long twisted cervix and twisted to the R because glans penis= corkscrew shape, how interlock- must put on pressure to ejaculate
boar puberty
average 9 months
crossbred earlier than purebred boars
testosterone- penile growth + mounting behavior
penile frenulum breaks down
15 hours of daylight
sexual maturation
can reproduce
spermatogenesis, storage of semen and sperm, ability to ejaculate and ability to have coitus
boar semen
large volume- 150 to 300 ml/ejaculate (highest number sperm/ejaculate)
30-60 billion sperm/ejaculate
spermatogenesis- 35 days with 9-12 days for epididymal transport
ideal seme >65% motile, >100,000 sperm/ml, <20% morphologic abnormalities
ideal semen
if affected and lower the number than affect ability to conceive
gilt puberty
6-7 months of age (165 days)
240-300 lbs
boar effect- helps stimulate puberty via pheromones- continuous fence line exposure, or full physical contact 10 mins/day (stimulate GnRH FSH and LH)
nuliperous
not given birth
primipherous
given birth to 1 offspring (litter)
pluriphorus
given birth to multiple
estrous cycle- sow
non-seasonal polyestrus
slight decrease in fertility during late summer
cycle length- 21 days
follicular estrogen causes standing heat (1-3 days)- duration of estrus, only receptive during this time
single follicular wave
estrous cycle hormones
non seasonal
progesterone rise around day 10, no negative feedback inhibition on FSH
FSH= pulsatile until day 15 then drops before rising during ovulation
luteolysis of CL caused by PGF2a decreasing progesterone no conceptus
ovulation
occurs 2/3 prior to end of estrus
number oocytes variable (15-20)
increase number oocytes- flush feeding, increase feeding few days to 2 wks before estrus to increase follicles
follicle to corpus hemorrhagicum to CL
CL
functional by day 5-6
won’t respond to exogenous PGF2a before day 12-13
if not pregnant uterus releases PGF2a which naturally lysis CL and the sow can return to estrus
estrus
standing heat- sow allows mounting by the boar
back pressure test- firm pressure on back or sacrum causes sow to show standing heat (lordosis)
avg. 2-3 days
2ndary signs- restlessness during feeding, not settling down after feeding, frequent small volume urination, ear cocking, red and swollen vulva with mucoid discharge
Boar pheromones
5a-androstenon= bound to proteins in saliva and when in heat salivate
helps to stimulate estrus in sows, puberty in gilts and mounting behavior in young boars
pregnancy
gestational length in the sow= approximately 3 mo. 3 wks 3 days
diffuse, epitheliochorial placentation
100% oocytes fertilizes and embryos enter uterus 2-4 days after conception
20-30% die within 1st 30 days because of uterine capacity so that embryo spaced out with trans nutrient migration of embryos
migrate throughout for 2 wks
litter size
variable
11 pigs average
implantation
day 14-18
embryos secrete estradiol between day 10-11 maternal recognition of pregnancy (estrogen in pigs, not IFN)
a second E2 peak occurs after day 14
sows pregnancy= CL dependent throughout
maternal recognition of pregnancy
pregnant sow, blastocyst secretes E2 and PGF2a not absorbed so CL not lysed
non pregnant cycling sow
PGF2a acting on CL on ovary causing luteolysis and oxytocin release
PGF2a released if not pregnant at day 15
pregnancy maintenance
2 embryos per horn- needed for pregnancy maintenance up to 30 days
2 fetuses required to maintain pregnancy after 30 days
parturition
occurs naturally in late afternoon and night
average farrowing takes 2-5 hours
pigs delivered at 15 minute intervals
placentas delivered within 4 hours after delivery (post parturition)
induction of parturition
ensures attendance of farrowing- increase survival rate of pigs, change to cross foster pigs from large litters to sows with small litters
pregnancy CL dependent- PGF2a
treat sow 2 days before due date (no more than 3)
most will farrow within 36 hrs
if no response within 24 hrs, can give oxytocin
lactational anestrus
most sows unable to cycle while nursing
allow pigs to nurse for 21 days (allows for uterine involution)
wean pigs- sow will return to estrus by 28 days post farrowing
boar exposure can help to synchronize sows
weaning
sows weaned during summer may take longer to return to estrus - decreased feed intake
ensure sow has adequate nutrition during weaning- subsequent litters may be smaller
