Swine Theriogenology Flashcards
What is a gilt?
Primiparous female
What is a sow?
Multiparous female
What is a barrow?
Castrated male
What is a boar?
Intact male
What type of cyclicity do pigs have?
Non-seasonal polyestrus
How long is the estrous cycle in swine?
18-23 days (21 day average)
What is the gestation length for swine?
114 days (3 months, 3 weeks, 3 days)
When does puberty occur?
At 6-7 months of age and/or at weight of 220-240 pounds
Boars attain puberty sooner
How long does standing heat last?
40-70 hours
How is breeding initiated?
Sow seeks out male
Displays erect ears and stands perfectly still while mounted
Erection occurs after mounting
Boar has a corkscrew penis which
How long does mating last?
5-8 minutes
What is the volume of ejaculate?
Large (150-200 mls)
What is maternal recognition in the gilt or sow?
The conceptus produces estradiol which is the signal for maternal recognition of pregnancy
Estradiol causes the PGF2α to be rerouted into the uterine lumen rather than toward the ovary
Intraluminal PGF does not cause luteolysis
True or False: essentially all eggs are fertilized in swine.
True
When do the embryos enter the uterus?
48 hours after ovulation
When did fetuses hatch their zona?
Day 6
When do the fetus distribute evenly through the uterine horns?
Days 9-11
When does implantation begin in pregnancy?
Day 13
When does MRP occur?
Day 14
What must be present for pregnancy to be maintained?
There must be at least 4-5 viable embryos on day 12
What percentage of EED of fertilized embryos occurs?
25-40%
When are most embryos lost?
Prior to MRP
Others are lost prior to day 40
When can pregnancy diagnosis be done?
Boar exposure 18-23 days post breeding
Rectal US 25-30 days post breeding
B-mode transabdominal US at 18-22 days
What is done for BSE of boars?
History
PE
Libido
Semen collection with gloved hand technique over dummy
Electroejaculation can be used, but requires anesthesia
What is the color of semen?
Opalescent-milky-yellow
How much is the gel free fraction of semen?
150-250 mos
What is the total amount of sperm?
Around 40 billion
What percent of semen is progressively motile sperm?
70-90%
What percent of sperm is morphologically normal?
> 70%
How can you induce puberty?
Expose gilts older than 150 days to a mature boar twice daily for 30 minutes (Whitten effect)
What is inducing puberty very effective at?
Inducing cyclicity
True or false: vasectomized boars are not useful when trying to induce puberty
False, vasectomized boars can be used
What drug can be given to induce puberty?
Injection of PG600
What are the economic benefits to estrus synchronization?
Farm labor better managed
Estrus detection can be intesnified
Synchronized farrowings allow for higher survival
Manage gilts, sows, and piglets in groups
Explain the group weaning technique for estrus synchronization
Group weaning at 21 days postpartum
80% will show estrus in 4-8 days
Easy and cost effective
Explain the progestagens technique for estrus synchronization
Artifical CL
Suppress estrus and cause synchrony upon removal
Good results with altrenogest PO x 14 days with estrus 5-7 days after last feeding
Swine product is called Matrix. With this feeding, you can start at any point in the cycle and they will still come into estrus 5-7 days after you stop feeding it.
Explain the prostaglandins technique for estrus synchronization
They are not typically used because the CL is refractory to PGF until day 12-14
Used to treat a group of pregnant animals causing abortion followed by synchronized fertile estrus
When are sows bred?
After estrus is first detected and 24 hours later
When are gilts bred?
After estrus is first detected and 12 hours later
When should pigs be weaned?
At 3-4 weeks after birth
When does estrus occur?
3-7 days following weaning
How often is a litter wanted?
Every 5 months
How frequently is the boar collected for AI?
Twice weekly over a phantom
Which fraction of semen is collected for AI?
Sperm rich fraction
What is the semen diluted with?
Extender: Androhep or SafeCell can be used to store boar semen for up to 10 days
What is the AI dose?
60-100 mls containing 2-3 billion sperm or 1 billion sperm per day of storage
What increases pregnancy rates and litter size with AI?
Double insemination
True or false: AI with fresh semen can be as good as natural service
True
How much lower are pregnancy rates for gilts compared to sows?
10-15%
Explain the process of farrowing including time intervals
Swelling of vuvlar lips beginning 4 days prepartum
Restlessness/nesting behavior starts 24 hours prior to farrowing
Duration averages 3 hours but can be 30 min to 10 hours in length
Interpiglet interval is 15-20 minutes
Fetal membrane expulsion averages 4 hours by can take up to 12.5 hours
What are the advantages to induced farrowing?
Labor issues
Survivability, used to reduce re-weaning mortatlity
More attention to piglets, reducing stillborns
Wean more piglets, so more money for the produce due to increased survivability
How can you induce farrowing?
On day 112 of gestation, give an injection of prostaglandin at 10-11 AM
Sows begin farrowing 20-30 hours after injection
75% should respond by the next day
Oxytocin can be used to “jump start” non-responders
Why should the piglets be removed during farrowing?
Prevents crushing, cannibalism, and colostrum deprivation
What are causes of dystocia?
Uterine inertia
Small pelvic size
Inadequate dilation of birth canal
What are signs of dystocia?
Straining followed by 4 hours without producing a piglet
Interval between piglets >1 hour
What are the options for c-section?
Immediate slaughter, surgery is a last resort
General anesthesia
Sedation followed by epidural/local bloc and restraint
Where is the incision made for c-section?
Dorsal and parallel to mammary chain. It originates just in front of and below the prefemoral fold
What is a common cause of irregular cyclicity and anestrus?
Cystic ovarian disease
What is the treatment for cystic ovarian disease?
Cull
What is zearalenone?
Mycotoxin found on corn and barley
What are the estrogenic effects of zearalenone?
Vaginal prolapse
Vaginitis
Abnormal cyclicity
Infertility
What is the diagnosis of zearalenone based on?
Signs and feed analysis
What causes brucellosis in swine?
Brucella suis
What are the typical signs of brucellosis in swine?
Abortion Stillborns and birth of weak piglets Infertility with repeat breeding Orchitis Spondylytis with paresis
How is brucellosis diagnosed in swine?
Card test followed by culture and serology
What is the treatment for brucellosis in swine?
No treatment
Reportable disease followed by cull and slaughter
True or False: brucellosis in swine is a true zoonoses.
True
How can brucellosis in swine be controlled?
Depopulation
Test young prior to breeding and farrowing
Surveillance
True or False: brucellosis is not found in wild hogs.
False, it is found in some
What is the SMEDI complex?
Stillborns
Mummies
Embryonic Death
Infertility
What are causes of the SMEDI complex?
Porcine parvovirus (PPV) Porcine reproductive and respiratory syndrome virus (PRRS) Porcine enterovirus (PEV) Pseudorabies (PRV)
What is porcine parvovirus seen in?
Gilts and young sows
What does porcine parvovirus cause?
Embryonic and fetal death
Mummification
Abortion is rare
Small litters with mummies
What can be used to prevent porcine parvovirus?
Vaccination and “controlled infection”
True or False: once an animal aquires a natural infection of porcine parvovirus, it is possible that they will get it again.
False. Natural infection leads to lifelong immunity
What are the symptoms of PEV?
The same as PPV
True or False: there is no vaccine available for PEV
True
What is the diagnosis of PEV done by?
Fluorescent antibody test on fetus
How is PEV prevented?
Controlled infection
What does PRRS cause?
Late term abortions
Premature births and stillbirths
Neonatal death
Respiratory signs in inweaned piglets
How is PRRS prevented?
Vaccination and controlled infection
What can PRV cause in young pigs?
Nervous signs Diarrhea Vomiting Respiratory distress Rapid death
Does PRV cause SMEDI in young pigs or adults?
Only adults
What more commonly occurs with PRV?
Late abortions and weak piglets
Mummies are not as common
How do you diagnose PRV?
Virus isolation, Fluorescent antibody test, and histopath of fetus
What are the signs of leptospirosis?
Usually asymptomatic in adults except for stillbirths, weak pigs, and late abortions
What is lepto shed in?
Persistently shed in the urine of infected animals
What are the fetuses like with lepto?
Edematous and icteric fetuses
How do you diagnose lepto?
MAT, darkfield microscopy
How do you prevent lepto?
Frequent vaccines, rodent control, water removal
How do you control an outbreak of lepto?
Antibiotics (streptomycin)
What does CO poisoning cause?
Abortion/still born in late term sows
Dark coloration of mucous membranes in sows
How do you diagnose CO poisoning?
History and value of CO >200ppm
How can you prevent CO posioning?
Improve ventilation
Remove/repair faulty heater