Pig Reproduction Flashcards
What type of breeding is practiced widely in swine?
Cross breeding
Using breeds or lines to take maximum advantage of their genetic type is know as what?
Breed complementation
The tendency for cross-bred progeny to perform differently than the average of their parents is known as what?
Heterosis or Hybrid vigor
What are 2 aspects of structural soundness to be considered when selecting replacements?
- General structural soundness
- Signs of: injuries, hoof cracks, sole bruises, foot rot
What are 4 problems that can be seen with the external genitalia of pigs?
- Infantilism
- Dorsally tipped vulva
- Male pseudohermaphroditism
- Mammary gland abnormalities
A pig with a small reproductive tract has what condition?
Infantilism
Pigs with a dorsally tipped vulva may have difficulty with what?
Mating
Male pseudohermaphroditism can lead to what type of vulva?
“Fishhook” or “sky-tipped” vulva
How many piglets do we want a sow to have?
10
What are 4 problems that can be seen with the internal genitalia in pigs?
- Hydrosalpinx or pyosalpinx
- Segmental aplasia
- Blind or missing cervix
- Oviductal adhesions
Hydrosalpinx or pyosalpinx can lead to what?
Obstruction of oviducts
What can segmental aplasia lead to?
Complete or partial infertility
How many functional teats should ideally be on each side of the sow?
What is the minimum total number of functional teats a sow should have?
- 6 on each side
- At least 10 functional teats
How many teats should be cranial to the umbilicus on each side?
3
How do the sows uterine horns appear?
Long and tortuous
What is the average age a pig goes into puberty?
5-8 months
What is the average weight at which a pig goes into puberty?
200-250 lbs
What breed of pig can reach puberty as early as 67 days?
Meishan
What breed of pig can reach puberty at 173 days of age?
Landrace
Which reach puberty earlier, purebreds or crossbreds?
Crossbred
Which breed is the latest to reach puberty?
When do they usually reach it?
- Duroc
- 224 days
What are 4 goals to managing a gilt pool?
- Keep large enough gilt pool to meet weekly breeding targets
- Daily boar exposure will stimulate puberty
- Gilt in heat: use sterile boar 1st heat then fertile boar 2nd heat
- Aim for large litter size and good nursing ability in gilts
What are 3 possible factors for hastening the onset of puberty?
- Movement/mixing of females
- Length of day (long)
- Boar effect
What are 2 factors that can delay the onset of puberty?
- Confinement housing
- Season
What are 2 ways lighting can affect the reproductive cycle in pigs?
- Long day length (16-18 hours) reduces age at puberty
- Detrimental to cycling females
Does the mixing of gilts and sows delay or hasten the onset of puberty?
Hastens the onset of puberty
What is the most common method used to hasten the onset of puberty in females?
Boar effect
What type of boar should be used for the “boar effect?”
Mature “smelly” boar
At what age is a gilt exposed to the “boar effect?”
Begin at 160-170 days of age
What type of contact should be used with the boar effect?
Continous direct contact
What type of estrous cycle does a pig have?
Non-seasonal polyestrous
What is the average length of the estrous cycle in pigs?
21 days
What is a difference between the estrous cycle of pigs and cattle?
No series of follicular waves as seen in cattle.
What is the length of estrus in gilts?
In sows?
- 36-48 hours
- 48-72 hours
When does ovulation occur in a sow?
Ovulation occurs 2/3 of the way through estrus (36 hour average)
When does ovulation in the sow happen in relation to the LH peak?
24 hours after LH peak
Multiple follicles rupture over what time period?
Over 1-4 hour period
When is ovulation rate largest in sows?
Largest over first 3 parities
Which litters are usually the largest in a sow’s life?
4th to 6th
What are 6 signs of estrus in the pig?
- Vulva swelling and redness
- Vaginal discharge
- Restlessness and vocalization
- Actively seeking boar
- “Pricking” of ears
- Lordosis response “back pressure test”
How often should sows be checked for estrus daily?
Twice a day
Change boars when checking for estrus to prevent what?
Prevent familiarization
What are 2 things that should be avoided when trying to detect estrus in sows?
- Avoid prolonged exposure to boars
- Avoid ventilation (Dilution of pheromones)
What can be used to imitate the smell of a boar?
“Stink stick” or “Boar mate”
What is the strategy used for weaning pigs?
All-in/all-out
When does estrus occur with the all-in/all-out strategy?
4-7 days post-weaning
How old do non-cycling gilts need to be before PG 600 can be used?
Greater than 165 days of age
What is a synthetic progestogen that can be used as a progesterone source?
How is it given?
- Altrenogest (MatrixR)
- Adding it to the feed
Altrenogest should be fed at a rate of what?
15-20 mg/hd/day for 14 days
How is Altrenogest mixed with the pig ration?
Mix dose in 1 lb of ration and then feed remaining diet
When do females show signs of estrus with Altrenogest?
4-7 days after withdrawal
What is a drug that can be used to induce abortion in sows?
Lutalyse (Dinoprost tromethamine)
Can pigs be “short-cycled?”
Why?
- No
- CL is not responsive until after day 12-13
When should Lutalyse be given?
between days 15-60 of gestation
How many days after Lutalyse is given will estrus occur?
4-7 days
When should semen be deposited in the sow?
Within 12 hours of ovulation
When does maternal recognition of pregnancy occur?
How?
- Days 11-12
- Estrogenic compounds
A minimum of how many embryos is necessary in pigs for maternal recognition of pregnancy?
4
What are 3 categories of traits looking to be improved through boar selection?
- Carcass yield/quality
- Feed efficiency, rate of gain
- Overall productivity of the herd
What are 2 general areas that should be included in a soundness/conformation exam?
- Musculoskeletal injuries
- Inherited defects
What are 3 examples of inherited defects that can be passed on by the boar?
- Hernias
- Cryptorchidism
- Rectal prolapse
Which sex gland does the boar not have?
Ampulla
What are 3 methods of semen collection that can be used on boars?
- Artificial vagina
- Electro-ejaculator
- Gloved hand method
What is the preferred technique for semen collection in the boar?
Gloved hand method
What are 4 things semen evaluation involves?
- Measuring volume
- Assessing progressive sperm motility
- Evaluating sperm morphology
- Calculation of total sperm numbers
What are 2 measurements to use with the ejaculate?
- Weigh the ejaculate
- Measure the actual volume of the ejaculate using a graduated cylinder
One mL of boar ejaculate is equivalent to approximately how many grams?
1 gram
What are 6 things ejaculates are evaluated for?
- Color
- Opacity
- Odor
- Sperm motility
- Concentration
- Individual sperm cel morphology
The most subjective measurement of semen is what?
Motility
More individual sperm cell assessments can be made with what system?
Computer automated semen analysis (CASA) systems
What sample size is need for CASA system analysis of semen?
2 uL
The total sperm numbers in the ejaculate during on-site evaluation is known as what?
Sperm concentration
What is the most costly lab technique dealing with semen?
Sperm concentration
What is a rapid and effective on-farm evaluation that is less expensive than CASA that can be calibrated for evaluating boar semen?
Spectrophotometry
What sample size is needed when using a hemacytometer?
20 uL extended semen sample
What is the normal volume for boar ejaculate?
100-500
How should semen extenders be stored for boar semen?
Refrigerated until needed
What can be used to help reduce the incidence of “cold shock” with extenders?
Water baths to maintain the temperature
What is the temperature of the water bath used to maintain the temperature of the semen extender kept at?
37 C
How long should semen extender sit in the water bath?
Approximately 1 hour prior to use.
What is the recommended dilution range (by volume) of semen to extender?
1:4 to 1:10
When should diluent be added to the semen in reference to temperature?
When the temperature of the two are equal.
What are 3 examples of containers that can be use for extended semen samples?
- Tubes
- Couchette bags
- Bottles
What should the volume of the insemination dose be?
80 to 100 mLs
What is the dose range of number of normal sperm require per dose of semen?
3-5 billion sperm
Semen should be stored at what temperature?
16-17 C
Semen should be protected from what when stored?
UV light
What should be done to semen in storage that will allow it to be resuspended in the diluent?
Gentle rotation of the semen
What are 5 advantages of using AI in pigs?
- Allows moe extensive use of older boars on lighter weight females
- Decreases number of boars and time required for breeding when estrus is synchronized
- Promotes development of a closed herd
- Allows introduction of new genetic material into a herd with minimum risk of disease
- Can examine semen to make sure it is alive
What are 3 disadvantages to using AI in pigs?
- Higher level of management in order to be effecting (semen handling and processing)
- Risk of disease is of greater importance
- Increased margin of error (human error)
What are 3 physical signs that would indicate it is too early to breed?
- Vulva heavily red and swollen
- Hardly any mucus on vaginal mucosa
- Negative back pressure test, only standing reflex in present of a boar
What are 3 physical signs that would indicate it is time to breed?
- Vulva moderately red and swollen
- Vaginal mucosa with mucus
- Positive back pressure test
What are 3 physical signs that would indicate it is too late to breed?
- No redness or swelling of vulva
- Sticky vaginal mucosal
- Negative back pressure test, only standing reflex in presence of a boar
What is necessary if there is a positive back pressure test 24 hours after AI?
2nd mating
When using AI, what should be done with the boar?
Move boar in front of 2-3 estrus females that are to be inseminated.
When does the female need to be exposed to the boar when being bred AI?
Before beginning of insemination
What should be done to the vulva prior to breeding via AI?
Clean with a dray paper towel
How should the catheter be inserted into the female?
Part lips of vulva with one hand, gently insert catheter into vagina pushing forward and upward for first 6-8 inches.
How far should the catheter be inserted when breeding via AI?
Advance until resistance is felt.
What can be done to stimulate uterine contractions in the female?
Rub the underline
How long do normal services take with AI in the female?
Do gilts take less time or more?
- 5-10 minutes
- Gilts take more time
What might have to be done to the bottle when inseminating via AI?
Tip the bottle down to slow the insemination.
What should be done to the female if she lays down during AI?
Continue with procedure as she lays down, do not try to get her up.
What would slapping a female that has played down during AI in order to get her up do?
Inhibit the release of oxytocin and uterine contractions.
How is the catheter removed after AI?
Clockwise rotation of spirette or by gently pulling on the foam tip type.
What should be done to prevent the back flow of semen after insemination?
Bend the catheter and continue to rub the underline.
What should the tip of the catheter be checked for?
What should be done if this is found?
- Blood
- Record it
