Swine reproduction (Risco)

Question 1

Boar repro anatomy

Penis

Testes

accessory sex glands

Answer 1

• Penis: fibroelastic, corkscrew shaped glans (like bull)
• Testes: caudally oriented (upside down)
• No ampullae, Bulbourethra gland, vesicular gland

Question 2

The sow repro organs

Uterus

Corpora lutea

Cervix

Answer 2

• Uterus: Bicornuate
• Corpora lutea: Red
• Cervix: long and twisted

Question 3

Boar

Puberty

Answer 3

• Reached around 9 months
• Crossbred boars reach puberty before purebreds
• Testosterone
  
  • causes penile growth (sigmoid flexure)
  • Mounting behavoir
• Penile frenelum breaks down
• Increased by more daylight (NOT SEASONAL POLYESTROUS….?)

Question 4

Boar Semen collection method

Answer 4

Gloved hand

Question 5

Boar semen

Answer 5

• large volume: 150-300 ml/ejaculate
• 30-60 billion sperm/ejaculate
• Spermatogenisis
  
  • 35 days
  • 9-12 days for epididymal transport

Question 6

Ideal boar semen

Answer 6

• 65% motile
• 100,000 sperm/ml
• < 20% morphologic abnormalities

Question 7

Boar pheromones

Answer 7

• 5alpha-anrostenone
• Bound to proteins in boar saliva
• stimulates
  
  • estrus in sows
  • puberty in gilts
  • mounting behavoir in young boars

Question 8

Gilt

Puberty

Answer 8

• 6-7 months of age (165 days)
• 240-300 lbs
• ‘boar effect’
  
  • stimulates puberty via pheromones
  • continues fence line exposure
  • full physical contact 10 minutes a day (in prepubescent bulls)

Question 9

Sow

Estrous cycle

Answer 9

• Non-seasonal polyestrus
• slight dec fertility during late summer
  
  • heat stress
• Cycle length: 21 days (17-25)
• Single follicular wave
• follicular estradio causes standing heat (2-3 days)

Question 10

Estrous cycle follicular wave

hormones and consequences

Answer 10

1. Recruitment of follicles
2. Selection of follicles to become dominant => pre ovulatory follicles
   
   1. In cows dom follicles in first wave can become atritic
   2. Estrogen has negative feedback on LH release
   3. New follicular wave
3. When corpus luteus is lysed, progesterone is removed
4. No progesterone means no negative feedback on LH
5. Dominant follicle produces Estrogen
6. Estrogen provides positive feed back in hypothalamus
7. Hypothalamus releases GnRH
8. GnRH surge and LH surge and ovulation happens

Question 11

Flush feeding

Answer 11

• Inc food ration of sows 2 weeks before estrus => more energy
  
  • promotes ovulatio of ALL the follicles

Question 12

Ovulation

Answer 12

• Follicle => Corpus Hemorrhagicum => Corpus Luteum
• CL functional by day 5-6
• Responds to PGF_2alpha after day 12-13
  
  • lyses CL
• Non pregnant sow uterus releases PGF_2alpha

Question 13

Exogenous PGF2alpha use in Sows

Answer 13

• Not used to lyse CL
  
  • Sows get colicy
• Used to induce parturition

Question 14

Sow

Estrus (standing heat)

Answer 14

• Standing heat: sow allows mounting
• Back pressure test: sows stand when pressure on back
• Avg 2-3 days
• Secondary signs estrus

Question 15

Secondary signs of estrus

Answer 15

• Restlessness during feeding
• Frequent small volume urination
• Ear cocking
• Red swollen vulva with mucoid d/c

Question 16

Breeding Methods

Answer 16

• Pen Mating (one and many)
• Hand breeding (one and one)
• Artificial insemination

Question 17

Boar selection for AI based on

Answer 17

• fertility
• weaning weight/age
• pork quality

Question 18

Pregnancy

Answer 18

• about 100% fertilized, 20-30% die first 30 days then 10% more till term
• Uterine capacity: limits number of surviving embryos
• Embryos enter uterus 2-4 days after conception, migrate for 2 weeks
• Embryos secrete estradio between day 10-11
  
  • maternal recognition of pregnancy
• Second E2 peak after day 14
• Sow’s pregnancy is CL dependant throughout pregnancy

Question 19

Stages after fertilization

Answer 19

• Oocyte
• Zygote
• Morula
• Blastocyst

Question 20

Special blastocyst secretion

EXAM QUESTION

Answer 20

• Secretes estrogen, that blocks release of prostaglandin from uterus
  
  • maintains CL and thus progesterone and pregnancy

Question 21

Required for pregnancy maintenance

Answer 21

• 2 embryos per horn up to 30 days
• 2 total fetuses after 30 days

Question 22

Pregnancy Parameters

Gestation length

litter size

Placentation

parturition

Answer 22

• Gestation length: 114 days (3 months, 3 weeks, 3 days)
• Litter size: variable, 11 piglets on average
• Placentation: diffuse, epitheliochorial
• Parturition: farrowing

Question 23

Pregnancy diagnosis

Answer 23

• Failure to return to estrus at 17-25 days after breeding (back pressure test)
• Rectal palp: >90% accuracy after 30 days (Fremetis of uterine artery)
• Ultrasonography

Question 24

Pregnancy diagnosis

Ultrasound

Answer 24

1. Doppler - Rectal/Transabdominal
   
   • after 30 days of gestation term
   • detects inc blood flow to uterine artery, fetal heart, or umbilical arteris
2. Amplitude - Depth (A-mode) common
   
   • Detects fluid in uterus
   • 28-80 days after breeding
3. Real - Time (B-mode) common
   
   • 16-20 days rectally
   • Typically > 21 days gestation transabdominally

Question 25

Parturition

Answer 25

* late afternoon, night * 2-5 hours total, 15 minute intervals * Placentas delivered w/in 4 hours after delivery

Question 26

Common cause of dystocia in sows

Answer 26

* Uterine atony * Palp Sow after parturition to make sure nothing is stuck * most commonly something gets stuck in cervix or vagina

Question 27

Induction of Parturition

Answer 27

* Ensure attendance =\> inc survival of piglets, allows cross-fostering * Treat sows 1-2 days before due date (28 hours) * most farrow w/in 36 hours * If no response in 24 hours give oxytocin

Question 28

Weaning

Answer 28

* weaned at 21-28 days (7kgs) * Summer weaning delays return to estrus * because of decreased feed intake * Ensure adequate nutrition during weaning to ensure subsequent larger litter size

Question 29

Reproductive Diseases

Answer 29

1. PRRSV 2. Brucellosis 3. Parvo Virus * SMEDI * Adenovirus 4. Lepto 5. MMA (Postpartum Dysgalactia Syndrome) 6. Pseudorabies (Aujesky's Disease)(Herpes Virus) 7. Swine Influenza (H1N1 & H3N2)

Question 30

PRRSV Porcine Respiratory and Reproductive Syndrome Virus General

Answer 30

* Most imp dz to swine industry * respiratory signs * wean-finish * Reproductive losses in all stages * abortions * stillbirths * eed (early embryonic death)

Question 31

PRRSV Etiology Epidemiology CS

Answer 31

* Etiology * Lelystad virus * arterivirus * strain variations * pathogenicity * Epidemiology * aerosol * pig to pig * semen transmission * CS * Acute (Epizootic) * Chronic: respiratory dz in nursury (Endemic)

Question 32

Parvovirus (SMEDI) General

Answer 32

* Common, ubiquitous, endemic * viremia, fetal vasculitis, death * \< 30 days EED * 30-70 days: mummies * 70 + immunocompetent * Prolonged gestations, small litters, etc * **primarily a Gilt disease**