Final Lecture 1 Flashcards
Describe the boar repro tract:
What type of penis?
How are testes oriented?
What accessory sex glands?
Fibroelastic penis with corkscrew shaped glans
Caudally oriented testes
Prostate, bulbourethral, vesicular (no ampulla)
What is the main accessory sex gland in the boar?
Bulbourethral gland
Describe the sow repro tract:
What type of uterus, ovaries, and cervix?
What is different about their corpora lutea?
Bicornuate uterus with paired ovaries and long/twisted cervix
Corpora lutea are red
Describe the sow’s estrus cycle: What type? When is there a decrease in fertility? How long is the cycle? What is different about their follicular wave? How long is standing heat?
Non-seasonal polyestrus Slight decrease in fertility during late summer 21 day cycle length Only one follicular wave instead of 2-3 Standing heat lasts 2-3 days
How can you increase the number of oocytes?
Make sure the sows are on a good nutrition plan before estrus…”flush feeding”
When are the CL functional in the sow?
Day 5-6
Producing progesterone
When will the CL respond to exogenous PGF2alpha?
Not until 12-13 days in the cycle
How can you tell if a sow is in estrus?
Back pressure test
What are some secondary signs of estrus?
Restless during and after feeding
Frequent small volume urination
Ear cocking
Red swollen vulva with mucoid discharge
Describe boar semen
Large volume and high concentration
How long does spermatogenesis take in the boar
35 days plus 9-12 days for epididymal transport
What is ideal boar semen
More than 65% general motility
More than 100,000 sperm/mL
Less than 20% morphologic abnormalities
What are the three breeding methods?
Pen mating
Hand breeding
AI
How many oocytes are fertilized?
All of them
What limits the number of embryos that survive?
The uterus! “Uterine capacity”
What do embryos secrete for maternal recognition of pregnancy?
Estrogen
What is the sow dependent on for progesterone throughout the whole pregnancy?
The CL
How does the pregnant sow turn off PGF2alpha and prevent luteolysis?
The embryos secrete estrogen, which redirects the PGF2alpha from the blood vessels and into the lumen of the uterus where it is metabolized
How many embryos are needed to maintain pregnancy up to 30 days?
What about after 30 days?
Two embryos per horn up to 30 days
Two fetuses total after 30 days
How long is the sows gestation
114 days (3 months, 3 weeks, 3 days)
What type of placenta does the sow have
Diffuse epitheliochorial
How can you diagnose pregnancy in the sow, what do the methods detect, and at what time frames can you do them at
Failure to return to estrus 17-25 days after breeding
Rectal palpation (after 30 days)
US:
- Doppler (after 30 days) detects increased blood flow
- A-mode (28-30) detects fluid in the uterus
- B- mode (16-20 days rectally, more than 21 days transabdominally)
When does the boar go through puberty?
About 9 months
What could stimulate puberty in boars?
Longer daylight
Being a crossbred instead of a purebred boar is better
What pheromones do boars secrete, where does it come from, and what does it do
5 alpha androstenone
Bound to proteins in the boar’s saliva
Stimulates estrus in sows, puberty in gilts, and mounting behavior in other boars
When does a gilt go into puberty? how can you make it come faster?
6-7 months
“Boar effect”- allow fence exposure to boars or give full contact for 10 minutes a day
What is beneficial about inducing parturition
Increases survival rate of piglets
Can cross-foster piglets from larger litters to sows with smaller litters
How to induce parturtion?
Administer PGF2alpha 1-2 days before due date
If no response within 24 hours, administer oxytocin
What is different about sows weaned during the summer?
They will take longer to return to estrus and subsequent litters might be smaller
What are the two common infectious repro diseases of pigs
Porcine respiratory and reproductive virus (PRRSV)
Parvo virus
How is PRRSV transmitted?
Aerosol and semen
Clinical signs of PRRSV
Resp signs from weaning to finishing
Losses in all stages of production (abortions, stillbirths, and early embryonic death)
What does parvo virus cause in the pig
Viremia, fetal vasculitis, early embryonic death, mummies, prolonged gestation, small litters, etc
Who does parvo primarily affect
Gilts
