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Small Ruminant Abortion & Porcine Reproduction

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sihirlifil's version from 2017-10-04 17:05

Small Ruminant Abortions

Question Answer
**Bacterial causes of abortionCapmylobacter fetus/jejuni (esp sheep)
Chlamydia abortus (esp goats)
Coxiella burnetti (REALLY infective & zoonotic)
Brucella ovis
Leptospirosis
Listeriosis
Salmonellosis
**Viral causes of abortionBluetongue
Border disease
Cache valley disease
Protozoal cause of abortionToxoplasma gondii
Non-infectious causes of abortionStress& trauma
Locoweed abortion
Iodine deficiency
Selenium deficiency
Most common cause of abortion in sheep in US?Campylobacter fetus/jejuni
Campylobacter: source of infectionAborted fetuses & placentae
Campylobacter: incubation period7-60 days
Campylobacter: CS?Late term abortions
+/- diarrhea
Mucopurulent vaginal discharge
**Campylobacter: pathologyEdema & necrosis of placenta, subq edema, pleuritis, peritonitis, hepatitis/liver necrosis (target lesions!)
Campylobacter: controlTetracyclines (long-acting oxytet/oral tetra) good in abortion storm
Remove pregnant ewes from infected pastures/areas (i.e. aborted fetuses, infected placentas)
Campylobacter: preventionVaccination prior to breeding or during outbreak (takes 2 weeks to develop sufficient immunity to stop abortion)
Chlamydia abortus: aka?Enzootic abortion of ewes (EAE)
Most common cause of abortion in goats in US?Chlamydia abortus
Chlamydia abortus: source of infxn?Carried by birds, persists in feces of affected animals
Chlamydia abortus: incubation period50-90 days
Chlamydia abortus: CS?Late term abortions
+/- Bloody vaginal discharge prior to abortion
+/- Retained fetal membranes
Chlamydia abortus: pathologyPlacentitis involving cotyledons & intercod areas
Thickened placenta with gray/white cotyledons
Fetus expelled fresh or autolysed
+/- birth of weak kids
Chlamydia abortus: dxCharacteristic inclusion bodies in impression smears from fetal lungs, spleen, liver, or placenta (or vaginal smears from dam)
Difficult to culture
Serology (ELISA, IFAT)
Chlamydia abortus: Prevention & controlVax variably effective :/
Prophylactic oral tetracyclines in whole flock if chronically infected
Coxiella burnetti: CS?Abortion rates 5-35%
Ewes normally immune after abortion, become carriers
Coxiella burnetti: pathologyPlacentitis
Coxiella burnetti: dxHistology, serology, culture
Coxiella burnetti: ControlLong-acting oxytetracyclines to control abortions, doesnt preven carrier state
NO VACCINE IN USA!
Toxoplasma gondii: common cause of abortion?YES! Abortion rates vary 5-100% (either sporadic or storm)
Toxoplasma gondii:transmissionOocysts in cat feces
Toxoplasma gondii: CS?30-90d: resorption, abortion, maceration, or mummification
>120d: stillbirth OR birth of healthy lamb
No CS in ewes (immunity lifelong)
**Toxoplasma gondii: pathology**Cotyledons are gray-white, yellow foci of necrosis & calcification; INTERCOT AREA NORMAL!
Toxoplasma gondii: dxIsolation, serology
Toxoplasma gondii: txMonensin in feed
Toxoplasma gondii: control & preventionPrevent cat access to feed & pastures
Spay current cats & prevent young new cats moving into territory (hard w/ feral cats!)
Brucella ovis: common cause of abortion?Rare in US and Canada
Brucella ovis: transmissionMucus membranes (vag, preputial, conjunctival) from ram to ram/ewe
Brucella ovis: dxCulture, complement fixation, ELISA
Brucella ovis: txTest & cull positive
Brucella ovis: CS?Epididymitis & orchitis in males
Leptospirosis: most common serovar?L. hardjo
Leptospirosis: CSEwes systemic (pyrexia, agalactia, icterus, hburia)
Late term abortions
Leptospirosis: dxDark field microscopy, immunofluorescence, silver stain placenta, fetal tissues & fluids
Leptospirosis: prevention & controlVaccination
Control rodent population, clean water supply
Listeria monocytogenes: CS?Abortion, encephalitis & septicemia
Listeria ivanovii: CS?Abortions in sheep
Listeria monocytogenes: transmission?Linked to feeding silage contaminated with soil, bird, or mice feces
Listeria monocytogenes: pathologyMicroabscessation in liver & brain
Salmonellosis: most common speciesS. arizonae most common in USA
Salmonellosis: CS?Occasional abortion storms
Dams systemically ill (high mortality, fever, depression, metritis, RFM)
Border disease virus: CS?Resorption, abortion, mummification or maceration, birth of weak lambs
Affects myelination of nerve cells
Hair follicles affected & produce hair instead of wool
Nervous signs ("Hairy shakers")
Locoweed poisoning: more common where?Western USA
Locoweed poisoning: what's the toxin?Swainsonine
Increases PGF2a, impairs vascular supply of placenta & fetus
Locoweed poisoning: CS?Abortions/birth defects (arthrogryposis, hydrops, weak lambs)
Reduced fertility in rams
Iodine deficiency: cause?If sheep are fed non-iodized salt during gestation
Iodine deficiency: results inAbortion, stillbirth, fetuses have goiters (enlarged thyroid glands)
Selenium deficiency: results inEarly embryonic death
Abortion due to in-utero white muscle disease
Prolonged gestation & parturition (stillbirths)
Selenium deficiency: treatmentOral supplementation of selenium, parenteral selenium preparations
memorize

Porcine Comparative reproductive anatomy & physiology

Question Answer
Type of uterus:Bicornuate with LONG uterine horns
Ovary has...multiple ovulatory follicles
**Cervix looks likeCorkscrew-shaped (need specially-designed catheters for AI)
Male: which sex glands?Vesicular, prostate, bulbourethral (no ampulla of ductus deferens)
Male: penis looks likeCorkscrew shape
Special anatomical thing at end of male penisPreputial diverticulum
When are females in season?Regular (non-seasonal) polyestrous (same as cow)
Duration of estrous cycle48-72 hours
Time of ovulation24-36 hours after onset of estrus (mid-estrus) (same amount of time as cow)
How many oocytes ovulated per cycle?15-24
Progressive increase in ovulation rate until 4th to 6th litters
**How long is the CL refractory fo PGF2a effects?Until Day 11/12 (short window!) (cow day 0.5-5)
Reach puberty at5-6 months
Puberty defined byBreed
Body weight
Nutritional status
Management (housing, temp, exposure to boars, relocation/mixing)
Commercial hormones & pheromones
memorize

Porcine breeding management

Question Answer
"Boar effect" =Hastens onset of puberty in gilts (mixing prepuberty gilts with pubertic also does this)
Boar effect happens due to...Pheromones, especially 5-alpha-androstenone (produced from testosterone in submaxillary salivary gland)
Minimum 10 minutes daily exposure required
Fence-line teasing: what is it?Nose-nose contact still allowed, without having the boar in the same pen ('boar effect' still occurs, amplifies signs of estrus in females)
Commercial hormones & pheromonesPG-600 (400 IU of eCG, 200 IU of hCG)
Commercial boar scent
Estrus detection:Back pressure test (riding test)
Sows/gilts assume immoble stance, ears erect, lordosis
(Enhanced by presence of boar)
**How to synchronize estrus?Oral progestins in feed for 14-18 days
PGF2a (not practical, since CL doesn't respond until late in estrous cycyle)
How long after withdrawal of oral progestins does cycle start back up?Usually 4-9 days with appropriate boar exposure (prolongs diestrus)
Which breeding/mating systems are used?Pen mating, hand mating, AI
Pen mating: what happens?Group of sows with boar inside a pen, common ratio is 8:1
Not used as much in recent years (inefficient use of boar power, some sows remain unbred despite being in estrus b/c boars are picky)
Hand mating: what happens?Gilt/sow taking to breeding pen & housed with a boar, supervision and assistance with intromission if required (rarely)
Mated every 24 hours when in standing heat
AI: what happens?Using fresh extended semen (either single-sired or pooled ejaculates), special AI pipettes, usually inseminated twice 12 hours (gilts) or 24 hours (sows) apart
How does mixing semen affect fertility?Greater fertility (pool together in lab)
memorize

Porcine pregnancy, parturition & dystocia

Question Answer
Fertilization rate =100% (close to)
Early embryonic mortality =20-30%
Late term losses =About 10%
Maternal recognition of pregnancy: day 10-11?Embryos chance in shape from spherical to filamentous, secrete estradiol
Maternal recognition of pregnancy: Day 14?Second increase in estradiol production
Maternal recognition of pregnancy: estradiol is believed to be ___Luteotropic/antiluteolytic (maintains CL)
At least ___ viable conceptuses required for pregnancy maintenance4! (certain lvl of estradiol...?)
___ is dependent throughout gestationCL (like goat)
Placentation:Diffuse (fetal membranes contact endometrium throughout)
Gestation length =3 months, 3 weeks, 3 days (114 days)
Pregnancy diagnosis =Failure of return to estrus after mating is suggestive
Transrectal digital palpation of middle uterine artery (not popular in USA, can comfuse w/ ext iliac)Ultrasound (usually around day 30)
Farrowings usually happen when?60-75% happen at night
Signs farrowing is about to occur?Swollen mammary glands w/ colostrum beads at tip of teats, swollen vulva 24-48 hours before
Nesting behavior in last 12-24 hours
Duration of parturition =1-5 hours
Stillbirth rate5-10% (usually the piglets born last)
Are piglets usually born in cr or cd presentation?Can be both! Cr 60%, Cd 40%
How common is dystocia?Rare (1% all farrowings)
Criteria for dystocia?Failure to deliver piglets within 1-2 hours after onset of labor (fluid from vulva, been restless, put hand in and no progress)
Longer than 1 hour interval between piglets
Causes of dystociaUterine inertia (mostly 2ry)
Abnormal fetal disposition
Birth canal problems (smaller/abnormally shaped pelvis)
Primary vs secondary uterine inertia?1ry = obstruction (big piglet, pelvic malformation)
2ry = Muscle tired
How to manage dystociaGentleness & lubrication!!!
Oxytocin: make sure cervix is open & no obstruction 5-50 IU IM/SC/IV (causes uterine contraction, could rupture if obstruction. better to start at lower dose to avoid tetany)
How do we induce farrowing with drugs?PGF2a analogs (dependent on CL throughout gestation!)
Induce after 110 days gestation (earlier = increased fetal losses. need good breeding records!)
When will most sows farrow after PGF2a?Between 20-36 hours after
1 reason to induce farrowing?Want to concentrate for better supervision of farrowing
memorize

Porcine infertility

Question Answer
3 main causes for abortionPorcine reproduction & respiratory virus (PRRS)
Porcine parvovirus
Zearalenone toxicity
PRRS: 2 syndromesReproductive loss in pregnant sows/gilts
Respiratory syndrome in suckling piglets
PRRS: CS in pregnant sows/gilts?Abortions, stillbirth, mummification, weak piglets
Anorexia & agalactia in lactating sows = increased preweaning mortality
PRRS: important?Considered the most important virus affecting the swine industry!
PRRS: ControlBiosecurity (transportation, fomites)
Vaccination
Porcine parvovirus: mostly in who?Gilts/sows of low parity
**Porcine parvovirus: CS?Fetal deaths at different stages of gestation (some mummified, resorbed, stillborn)
Porcine parvovirus: spread how?Contaminated premises and veneral
Porcine parvovirus: controlVaccination before breeding (takes several weeks to develop immunity)
**Zearalenone toxicity: what is it? does what?Mycotoxin (fusarium from corn or wheat)
Estrogenic effects (CL persists)
Zearalenone toxicity: CS in prepubertal giltsPersistant vulvovaginitis (swollen & red), vaginal prolapse (normal in estrus but not prepubertal)
**Zearalenone toxicity: CS in sowsAnestrus (persistant CL), reduced litter size if bred
**Zearalenone toxicity: CS in boarsReduced testicular size & libido
Possible reasons for male infertilityHeat & cold stress
Vax-induced (PRRS, transient)
Nutritional
Inappropriate management (overuse)
Preputial diverticulitis
Male infertility: nutritional reasons?Over- & under-nutrition
Selenium deficiency
Zinc deficiency
Zearalenone toxicity
**Preputial diverticulitis: CS?Urine dribbling, pain, odor
**Preputial diverticulectomy: IndicationsDiverticulitis
"Balling-up" (entrapment of penis in diverticulum during attempts at mating, i.e. reduced fertility)
Minimize urine dribbling and odor from pot-bellied pigs kept as pets (removal of scent gland)
memorize