Procine reproduction

Question 1

boar anatomy

Answer 1

fibroelastic penis
corkscrew shaped glans
prepucial diverticulum (pocket in prepuce)
caudally oriented testes- UNIQUE, not well protected so have well developed thermoregulators

Question 2

boar accessory sex glands

Answer 2

vesicular gland, prostate gland, bulbourethral gland
NO ampulla

bull has sigmoid flexure (like bull)

Question 3

seminal plasma

Answer 3

non-cellular fraction of ejaculate

secretions from the testis, epididymis, and accessory sex glands

Question 4

semen

Answer 4

seminal plasma + sperm

Question 5

accessory sex glands

Answer 5

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

Question 6

the sow anatomy

Answer 6

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

Question 7

boar puberty

Answer 7

average 9 months

crossbred earlier than purebred boars

testosterone- penile growth + mounting behavior

penile frenulum breaks down

15 hours of daylight

Question 8

sexual maturation

Answer 8

can reproduce

spermatogenesis, storage of semen and sperm, ability to ejaculate and ability to have coitus

Question 9

boar semen

Answer 9

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

Question 10

ideal semen

Answer 10

if affected and lower the number than affect ability to conceive

Question 11

gilt puberty

Answer 11

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)

Question 12

nuliperous

Answer 12

not given birth

Question 13

primipherous

Answer 13

given birth to 1 offspring (litter)

Question 14

pluriphorus

Answer 14

given birth to multiple

Question 15

estrous cycle- sow

Answer 15

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

Question 16

estrous cycle hormones

Answer 16

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

Question 17

ovulation

Answer 17

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

Question 18

CL

Answer 18

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

Question 19

estrus

Answer 19

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

Question 20

Boar pheromones

Answer 20

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

Question 21

pregnancy

Answer 21

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

Question 22

litter size

Answer 22

variable

11 pigs average

Question 23

implantation

Answer 23

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

Question 24

maternal recognition of pregnancy

Answer 24

pregnant sow, blastocyst secretes E2 and PGF2a not absorbed so CL not lysed

Question 25

non pregnant cycling sow

Answer 25

PGF2a acting on CL on ovary causing luteolysis and oxytocin release

PGF2a released if not pregnant at day 15

Question 26

pregnancy maintenance

Answer 26

2 embryos per horn- needed for pregnancy maintenance up to 30 days

2 fetuses required to maintain pregnancy after 30 days

Question 27

parturition

Answer 27

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)

Question 28

induction of parturition

Answer 28

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

Question 29

lactational anestrus

Answer 29

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

Question 30

weaning

Answer 30

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