Swine Repro Flashcards

1
Q

Describe the basic anatomy of the swine repro tract

A

-the uterine body is relatively short
-uterine horn: non gravid horn is 1 meter in length, may double in length during pregnancy
-cervix is up to 25 cm in length
-long vaginal vault

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2
Q

T/F: it is common for the prolific females to have a ton of follicles

A

True
- can have 14-16 on each ovary on occasion
-good for production, but sows don’t have enough teats

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3
Q

Describe the basic physiology of the female pig estrous cycle

A

-HPG axis is similar to other domestic species
-females still develop surge center and males a tonic center
-one follicular wave per cycle
-18-24 days average length
-follicles produce estrogen leading to estrous behavior
-gilt estrus is 36-48 h, sows 48-72 h
-ovulation occurs 2/3 of the way through estrus (36 h average)
-ovulation occurs 24 hours after LH peak
-multiple follicles rupture over a 1-4 hr period

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4
Q

T/F: you can short cycle pigs with prostaglandin

A

False- not effective until after day 12-13
- by this time they are already close to ovulation
-can be used for abortions

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5
Q

What are some of the main signs of estrus in sows?

A

-vulva swelling and redness, vaginal discharge (white and chalky), restlessness and vocalization, increased motor activity (seeking out boar)
-actively seeking boar, pricking of ears, lordosis response

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6
Q

Will sows that come into heat early stay in shorter or longer?

A

Longer

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7
Q

What are the main factors that influence ovulation rate?

A

-Age: sows usually have 18-20 ova vs gilts usually have 12-14
-nutrition: higher in full fed gilts, flushing may increase ovulation rate
-breed: white or maternal breeds have higher ovulation rates

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8
Q

Describe ovulation in pigs

A

-occurs about 42 hours? after LH surge
-all of the follicles from both ovaries will ovulate over a short period of time
-timing of the ovulation can vary between females
-the life span of the egg is 8-12 h

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9
Q

Are pigs CL or placental dependent?

A

CL
-cant short cycle them as CLs not responsive until 2 weeks

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10
Q

Describe maternal recognition of pregnancy in pigs

A

-an estrogen compound causes it
-if no MRP, prostaglandin is release
-if MRP occurs, estradiol causes intraluminal PGF2 alpha release (so it doesnt get to ovaries) and prevents luteolysis
-MRP requires 4 embryos to be present, 2 in each horn

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11
Q

How can you select females sows for breeding?

A
  • good number of teats and conformation
    -good immunity
    -good feet and legs
    -good maternal qualities
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12
Q

What are some things to consider when helping a producer decide on purchasing?

A

Depends on individual operation goals
-are you raising your own gilts or purchasing? are you buying piglets? will you start with gilt purchase? are you buying a bred female or prebreeding?

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13
Q

What are some main considerations when selecting gitls

A

-selection based on various characteristics: feet and leg soundness, breed/genetics (litter size, etc), underline and vulva size, growth parameters- fast or slow growing, age at puberty and breeding
-todays gilts grow faster, reach puberty at heavier weights, and are mated leaner and at younger ages
-selection based on performance testing methods can help determine the most productive females
-selecting for leaner animals can at many times adversely affect repro

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14
Q

What lean growth traits should you select for?

A
  • must look at boar
    -look at backfat thickness, feed intake, feed efficiency, days to market
    -Hampshire’s and durocs, some patrons are known to be very muscled -aim for heterozygotes
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15
Q

What maternal traits should you consider when selecting?

A

-number born alive, number weaned, 21 day litter weight

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16
Q

Why do we want white pigs?

A

We like uniformity
-often breed to F1 females to select for this

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17
Q

T/F: you should use purebred grandparent stock to make F1 females

A

True

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18
Q

Describe the selection criteria for the musculoskeletal system and repro system

A

-for the musculoskeletal system, assess conformation and structure, feet and legs. pay attention to all of the joint angles as it is important that animals can do well on concrete
-for repro system: assess when they meet puberty, external genitalia and underlines. look for well developed normal sized vulva, smaller better for avoiding injuries

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19
Q

What specific things should you look for when looking at toes?

A

-examine size
-unevenness of toes can cause problems as well as injuries
-small toes, especially if close together can create soundness problems
-look for cracks, abrasions and/or swellings

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20
Q

What should you look for in terms of teat assessment?

A

-good spacing, 6-8 functional teats per side, no inverted or underdeveloped teats

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21
Q

When should gilts come into estrus?

A

-between 5-8 months when they weigh 100-125 kg
-landrace at 173 days of age, crossbreds reach puberty earlier than purebreds, durocs are latest to reach puberty (224 days)

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22
Q

Describe the lactational anestrus that sows exhibit

A

-suckling stimulus suppresses FSH and LH secretion leading to no follicular development
-removing all piglets removes suppression and sows enter estrus 4-7 days postweaning (can be influenced by genetics, nutrition, parity, litter size, BCS, and lactation length)
-allows for estrus detection and planning

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23
Q

What is the problem with delayed estrus postweaning?

A

-increases non productive sow days and maintenance costs

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24
Q

What is the target weight for breeding gilts?

A

-200 lb with at least 1 recorded estrus
-try not to have overweight at breeding or gestation as this can increase culling rate

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25
Q

What are sows generally fed?

A

-5 lbs corn-soybean meal diet per day for maintenance
-lactating sows may eat >14-15 lb/day
-be sure they dont get too fat!

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26
Q

Describe the normal prebreeding vaccination program?

A

Parvo, lepto, and erysipelas vaccine
-should be administered 3-5 weeks apart with the last one being 2 weeks prior to breeding
-if not vaccinated previously, only 2 weeks prior for sows

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27
Q

Describe some breeding targets in the swine industry

A

2.2-2.5 litters/sow/year, >19 pigs weaned/mated female/year, 21 day litter weight >120 lb, farrowing rate >85%, >10 piglets born alive, NPS days <60 and WEI <7 days

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28
Q

What are some methods of estrus detection that do not require humans to watch?

A

-boar bot, breeding saddles

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29
Q

Describe synchronization protocols in cycling females

A

-gilts and some sows: altrenogest 15 mg orally for 14 days
-weaned sows: triptorelin 200 mg intravaginal 4 days post weaning, breed on day 5

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30
Q

Describe the AM/PM rule for breeding

A

-If a gilt is in estrus in the AM, breed, then again in PM and then again 12 hours later
-sows: when you find in estrus, breed then breed again 24 hours later

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31
Q

Describe how you perform AI in pigs

A

-introduce rod at 45 degree angle
-on gilts they have ones that spiral, in sows they have spongey ones

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32
Q

How long is the boar orgasm?

A

3-5 minutes

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33
Q

Are BSEs routinely performed in boars?

A

NO
-there is a manual for it however

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34
Q

Why do people like hereford breed of pigs?

A

Novelty, do well on pasture

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35
Q

How are boars selected?

A

-for growth traits primarily
-can pass on maternal traits too
-if show pigs, they want big butts
-depends on breeding system: boar breeding, AI
-select for carcass yield, quality, feed efficiency, rate of gain, overall productivity of the herd

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36
Q

Why are boars castrated?

A

Boar taint is real

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37
Q

What is reproductive capacity best measured by for boars?

A

-testicular weight
-cant do scrotal circumference as they are non-pendulous
-can use calipers or ultrasound

38
Q

Describe some features of boar anatomy

A

Fibroelastic penis, sigmoid flexure
-preputial diverticulum- unknown purpose, might lubricate penis (collects grossness and some boars can masturbate into them)
-biggest glands are vesicular glands- huge volume of ejaculate
-bulbourethral glands are very muscular to support gel fraction
-small prostate
-orientation of testes like the cat (tail to tail)

39
Q

How can semen be collected in boars?

A

-AV- rare-have to be under GA
-electroejaculator- also rare- have to be under GA
-most commonly via the gloved hand technique

40
Q

What is the value of the AI boar?

A

-can collect 1-2 times per week
-3 billion sperm per dose
-20-50 doses per week
-1000-2000 litters sired per year
-offspring marketed 10000-20000
-gross income 1.7-3.4 million per boar

41
Q

What does semen evaluation involve?

A

Measuring volume, assessing progressively motile sperm, evaluating sperm morphology (including acrosomes), calculation of total sperm numbers

42
Q

What do you want sperm progressive motility to be?

A

70% at the minimum

43
Q

Which sperm abnormality is more common in boars than other species?

A

Acrosomal abnormalities

44
Q

What is responsible for the most contamination of sperm samples?

A

Improper water treatment when making extender

45
Q

What should the collection pen look like?

A

-clean, large, allows for good footing, safety for handlers, place for boars to put feet
-never vaccinate where you collect- only good things happen there

46
Q

How can you train boars to collect?

A

-get them familiar with the handlers (provide them food-they will like you for this)
-must be patient with them
-should work with each boar for 20-30 min per session
-can use prostaglandins to jumpstart them-will contract accessory sex glands

47
Q

What is the best way to analyze semen?

A

-stained slides with phase contrast microscope, can see bacteria
-still a manual process

48
Q

What are some developmental problems that can occur in boars?

A

-cryptorchidism (failure of one or both testes to descend)
-hypoplasia of penis (smaller than normal for age and size- more common in show pigs)
-persistent frenulum (tissue between end of penis and prepuce fails to regress)

49
Q

What can cause problems with extending the penis?

A
  • hypoplastic penis
    -persistent frenulum
    -behavioral - masturbation into preputial diverticulum
50
Q

How can you examine an untrained boar?

A

-TKX- due to cost
-reconstitute telazol bottle with 250 mg xylazine and 250 mg ketamine
-makes a 100 mg/mL solution of telazol
-dose at 4.4 mg/kg IM, can do half IV if quick procedure
** not reversible

51
Q

What are bozeman uterine forceps used for in boars?

A

to grab the end of the penis
- long enough to go through opening of prepuce, past diverticulum to penis

52
Q

What is the indication for preputial diverticulectomy?

A

Bad diverticulitis due to crap accumulating in there
-can lead to enlarged prepuce
-in boars where they ejaculate into it

53
Q

How do you perform a preputial diverticulectomy?

A

Perform lateral incision, dissect around the whole diverticulum, clamp and ligate large vessels

54
Q

When should you deposit semen into a gilt/sow?

A

Within 12 hours of ovulation
-optimal time of breeding is 18-24 hours apart on days 1 and 2 of estrus
-breed gilts on second or third estrous cycles to increase fertility rates

55
Q

Describe the events associated with fertilization in the sow

A
  • pregnancy is CL dependent
    -after fertilization, embryos will undergo cleavage and enter the uterus at the 4 cell stage
    -there is a 20-30% loss up to day 13
    -maternal recognition of pregnancy occurs on day 11-12 by estrogenic compounds
    -need a minimum of 4 embryos
56
Q

What is the type of placentation in the sow?

A

Diffuse microcotyledonary
- same as the horse

57
Q

Describe the fetal development in sows

A

-mineralization occurs between 35-42 days
-immunocompetence begins around day 70-75
-can measure crown to rump length to determine gestational age of fetus
*total gestation is 114 days (3 months, 3 weeks, 3 days)

58
Q

When during pregnancy is resorption possible?

A

Between day 0-35
- up until the fetus starts mineralizing

59
Q

When can you see mummification of fetuses/abortions?

A

35-114 days

60
Q

Why is it that some piglets in a litter can be mummified, while others are stillbirths and some are completely normal?

A

They all have a separate placenta and sac

61
Q

On average, what is the number of embryos that suffer from early embryonic death prior to implantation?

A

2-2.5

62
Q

If fetal death is within 14 days of pregnancy, will there be a regular or irregular return to estrus? What about if >35 days? In between?

A

14: Regular!
>35: irregular
14-35: might be regular, might be irregular

63
Q

What is an acceptable pregnancy loss rate on farms?

A

<5%

64
Q

With mummification of a whole litter, when will pregnancy progress to pseudopregnancy?

A

-at >114 days
-main causes are PRRS and parvo

65
Q

T/F: you should induce after day 116

A

True

66
Q

Define a stillbirth

A

Full term piglets born dead, but grossly normal
-lungs never inflated
-may die shortly before, during or immediately after birth

67
Q

What are some common noninfectious causes of infertility in female pigs?

A

Hydrosalpinx: most common cause of infertility, occurs secondarily to bursitis or peritonitis that results in adhesions

Cystic ovarian disease: second most common cause of infertility

68
Q

How can you diagnose cystic ovarian disease?

A

Via ultrasound
-will see multiple cysts or irregular cycles or anestrus
-does not respond to hormonal therapy
-can be caused by estrus induction agents
-generally bilateral
-no treatment really works

69
Q

How do you treat cystic ovarian disease in cattle?

A

ovsynch + CIDR

70
Q

What is PG600?

A

A combo of HcG and PMSG
- HcG has LH like activity, PMSG has FSH like activity

71
Q

What are the top 3 infections that cause abortions in swine?

A

PRRS, Lepto, secondary to viruses (flu causes the most)

72
Q

Describe some features of porcine parvovirus

A

-results in SMEDI=stillbirths, mummification, embryonic death and infertility (also caused by PRRS)
-results in no maternal signs
-females may nest and get mammary development but fail to farrow due to fetal mummification

73
Q

Describe the pathogenesis of parvovirus in pigs

A

-can be spread orally or venereally
-viremia leads to transplacental infections leading to fetal vasculitis and death
-depending on the day of infection, can see a variety of forms of fetal death
-litters may be carried greater than 114 days
-usually occurs in naiive replacement gilts
-sows infected do not normally show signs until farrowing

74
Q

How can you diagnose parvovirus?

A

-lesions of aborted fetuses
-look into vaccination program
-clinical signs of increased irregular returns to estrus and increased mummies
-serology

75
Q

How can you prevent parvovirus infection?

A

-proper acclimatization of replacement gilts
-regular vaccination of breeding herd
-no treatment except for supportive care for the aborting sows or gilts

76
Q

Describe the clinical features of pseudorabies in pigs

A

-herpes virus (always affect CNS, repro, resp)
-can cause encephalitis, repro failure, and reduced litter size
-recrudescence of virus from boars and/or sows under stress
-can be transmitted in semen

77
Q

Describe the pathgenesis of pseudorabies

A

-can be spread by nose to nose contact, feco oral, aerosol, or through semen
-clinical signs depend on age at time of infection: if young will see CNS signs
-weaned pigs and older see respiratory signs
-fever, anorexia, weight loss can occur at all ages
-resorption, abortion, and increased mummies and stillbirths can occur

78
Q

How do you diagnose pseudorabies?

A

-gross lesions +/- histological lesions (pulmonary edema, meningoencephalitis)
-virus isolation
-serology

79
Q

How do you control speudorabies?

A

-eradication programs: whole herd depopulation, test and remove all breeding swine, segregate offspring to an off site production unit
-vaccination with a G1 gene deleted product

80
Q

Describe the clinical features of swine influenza

A

-two types: H1N1 and H3N2
-usually causes more respiratory signs
-there is interspecies transmission
-spread by oronasal secretions and aerosols
-seasonal in october-march
-not considered a primary reproductive pathogen

81
Q

How do you diagnose and treat swine influenza?

A

Diagnosis through clinical signs and serology

Prevention and treatment: injectable antibiotics for secondary infections, could vaccinate in the face of an outbreak

82
Q

Describe some clinical features of PRRS

A

-Porcine Respiratory and Repro Syndrome
-caused by arterivirus
-sow mortality can be 5-10%
-can be transmitted in semen
-signs include agalactia, anorexic sow

83
Q

How is PRRS spread?

A

-direct pig to pig contact or aerosols
-two distinct forms: repro failure or post weaning repro disease

84
Q

Describe some diagnostics you can do for PRRS

A

-history and herd records
-herd serology
-virus isolation from aborted fetus, lungs, tonsils and lymph nodes
-sequencing the virus

85
Q

What is the prevention and treatment of PRRS?

A

-symptomatic therapy
-isolation and acclimatization of new entries
-herd stabilization
-vaccination with MLV (have ability to mutate) or killed product
-management techniques- no more cross fostering of litters

86
Q

What is hog cholera?

A

-classical swine fever
-reportable
-pig is the only natural host
-occurs when you feed raw garbage to hogs
-clinical signs include anorexia, cyanosis, fever, diarrhea, vomiting, and abortions
-can be transmitted in semen

87
Q

Describe the pathogenesis of lepto in pigs

A

-ZOONOTIC
-many different serovars
-L pomona most common
-penetrates mucous membranes, can be brought in by carrier animals
-clinical signs depend on stage in which females become infected but it usually results in mummified and macerated fetuses
-mild signs except for abortion
-immunity lasts for one year following abortion

88
Q

How can you prevent lepto?

A

-vaccination of herds every 6 months (generally in combo with parvo)
-antibiotics (tetracycline) to help to reduce shedding, does not eliminate carrier state

89
Q

Why is brucella such a concern in pig operations?

A

It is reportable
-causes pig abortion, stillbirths and infertility in sows, piglet mortality, orchitis in boars
-primarily introduced and transmitted by boar, can carry for >4 years
-infections can occur at coitus or by ingestion of infected material
-report positives to federal government, mostly eradicated from US
-test and slaughter is the method of choice for control
-buy replacement animals from certified brucellosis free herds

90
Q

Describe the pathogenesis of erysipelothrix

A

-many pigs carry the organism on tonsils without clinical signs
-organism can gain access via contaminated feed and water
-in acute cases the organism enters circulation via pharynx and infects blood vessels
-clinical course depends on stress levels and depends if acute or chronic
-can see arthritis in little pigs, fever and skin lesions in gilts
-abortion secondary to fever and septicemia

91
Q

What protozoa can cause problems in pigs?

A

-toxoplasma (causes individual abortion and stillbirth)
-eperuthrozoonosis (causes silent estrus or anestrus, abortion, weak and anemic pigs)- treat with tetracyclines, but does not remove carriers, can treat whole herd with arsenics

92
Q

What does zearalenone cause?

A
  • implantation failure
    -enlarged vulva with delayed maturity
    -increased vaginal and/or rectal prolapses
    -found in moldy corn
    -prepubertal males have reduced testicular development