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70 Cards in this Set
- Front
- Back
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Swine puberty
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Age: 6-9 months
230lbs cross-breds earlier than purebred |
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Factors affecting puberty in swine
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confinement delays onset; move gilts every 3 weeks; trucking gilts >180 days results in spontaneous induction 4-7 days later
seasonal effect: long days (16-18hrs) of light is optimal; negative effect from heat stress (Aug-Sep; summer anestrus) |
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Puberty: Boat effect
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introduction of boars to gilts @ 160-170 days hastens puberty
direct contact is best compared to intermittent exposure- smell and sound of boars pheromones- androstenol 25% become anestrus if no interaction w/ boars |
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Puberty - Swine: Estrus
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1st estrus is silent due to lack of progesterone priming
breed on second heat number of ovulations will increase with each estrus maximum fecundity at 2-4 ears |
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Estrous Cycle
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length is 21 days
Polyestrous lactation anestrus until weaning |
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Estrus in swine
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2-3 days
ovulation - 36 hours from onset breeding: 1st to 2nd day of estrus post-partum estrus within 5 days of farrowing lactational anestrus - resumes cycle 4-8 days after weaning |
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What are the signs of estrus in swine?
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back pressure test - standing - cardinal sign
other signs: restlessness, vulvar swelling, mucus discharge, actively seeks boar, ears elevated in presence of boar, champing of jaws with salivation 10-20 follicles ovulate over a period of 1-4 hours (gilts 10-15 follicles) |
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Diestrus in sows
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progesterone peaks at 7 days
non-pregnant: diestrus until 16 days CL responsive to PGF2a after day 12 (day 0 = ovulation) estrogen is luteotropic, prolongs the inter-estrus interval) |
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Breeding management (swine): flushing
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increase energy intake 2 weeks prior to estrus - results in 2-3 more ova; commonly done in gilts
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When are swine bred (breeding management)?
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12-24 hrs apart on day 1 and 2 of estrus
farrowing rate increases when different boars are used (heterospermic insemination) farrowing rate: 80-90% |
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Breeding Management: Synchronization
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1.Timed Group Weaning
2. PGF2a 3. Progestins |
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Timed Group Weaning in Swine
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Wean on Thursday
Breed on Monday |
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Synchronization: PGF2a in Swine
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short cycling is not practical due to CL's response - 12d after ovulation
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Synchronization: Progestins in swine
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upon removal, return to estrus in 4-6 days
Altenogest (Regumate) |
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Pregnancy in Swine
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Day 2: Fertilized ova enters uterus
Day 9-12: intra-uterine migration of zygotes results in spacing of embryos Day 12-16: rapid elongation of blastocyst; implantation occurs around day 15-17 with diffuse epitheliochorial placenta Day 12: maternal recognition - estrogen produced by blastocyst |
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You need a minimum of ________ embryos to maintain a pregnancy in swine.
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four
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Pregnancy diagnosis in swine
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non-return to estrus, serum progesterone, serum estrone sulphate, ultrasonography
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What is the normal gestation length of swine?
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115 days
(range 111-116, 3 months, 3 weeks, 3 days) |
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Signs of Parturition in swine
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nesting behavior
restlessness anorexia enlarged vulva (1 week prior) Mammary distension with milk in last 24 hours |
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Stage 1 of parturition in Swine
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restlessness
vulval discharge |
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Stage 2 of parturition in swine
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first piglet enters cervix and causes increased myometrial contractions
4hrs (20 min- 12 hours) |
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Stage 3 of parturition in swine
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passing of placentas may occur at 2-3 times during parturition, majority are expelled after the last fetus is delivered
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Post-farrowing: normal and abnormal
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Normal: quiet, nursing, voids large amounts of urine
Abnormal: restlessness, fetid discharge, look for retained piglets |
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Pharmacological control of Reproduction in Swine: Targeted control
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Acyclic (anovulatory) females - to stimulate follicular growth, estrus, and ovulation
Cycling females - estrus synchronization |
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Acyclic Swine
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non-pregnant sows; prepubertal gilts; postpartum sows
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How do you induce estrus in adult acyclic swine females
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by administering hormones:
eCG (PMSG) - FSH like activity hCG - LH activity |
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When is there a problem with gilts coming into puberty and what would you do to induce puberty?
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problem when gilts not showing estrus 42 days after pen-mates
-change environment and boar exposure -administer gonadotropins after 5 months -induce estrus in 90% w/ 75% farrowing rate w/ good litter size (7-10) PG 600 (PMSG - 400IU and hCG - 200IU) |
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Induction of estrus in postpartum sows
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1. group weaning - initiates follicular growth and onset of estrus
-affected by season, nutrition, early weaning, heavy lactation -delayed estrus if not within 10 days of weaning (first litter gilts; summer and fall - seasonal anestrus) RX: PG 600 - fertile estrus in 7-8 days; repeat trmt - if no estrus w/in 7 days |
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Control of parturition in swine
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1.useful in reducing stillborns (useful after 110 days; accurate records and farrowing supervision is essential)
2. PGF2a- lutalyse or cloprostenol -see parturition w/in 20-36 hrs SE: increased resp., salivation, urination may reduce incidence of mastitis, metritis, Agalactia Complex - may need assistance and oxytocin |
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Reproductive goals in swine
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farrowing rate >85%
pigs born live/litter - 10.5 stillbirths <7 Mummies <1.5 Normal loss: 8.5% of all piglets |
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Hydrosalpinx in swine
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common; sterile 35% of gilts and sows
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Polycystic ovaries in swine
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2nd most common cause of non-infectious infertility
luteal/follicular irregular cycle/anesrus single cyst - can cycle can be seen in any stages of cycle or pregnancy |
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Anatomic/congenital abnormalities in swine that cause non-infectious infertility
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segmental aplasia
uterus unicorn hermaphrodites or intersex |
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Environmental Causes of Non-infectious infertility
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high temp: >30 degrees C
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Nutritional causes of non-infectious infertility in swine
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must be severely inadequate
rare |
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Pregnancy Wastage in Swine
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stillborn: fetal death shortly before, during, or after birth; lungs don't float
mummified fetus - died in-utero after 35 days abortion - birth before 110 days of gestation early embryonic death: embryonic loss before 35 d; embryonic loss during migration in uterus and at implantation (if fewer than 4 embryos, won't maintain preg.) |
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Early Embryonic Death (EED) in swine
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embryonic loss before 35 days
embryonic loss during migration in uterus and at implantation if >= 4 embryos -pregnancy will continue, or regular return to estrus EED after implantation - irregular return to estrus |
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Piglets become immune-mature at _________, so if they get infected with one of the problems we talked about, if we take a blood sample and see a titer, it tells us they reached ________ and were able to mount an immune response
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70 days
day 70 |
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Immune response in piglet fetuses
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at 70 days
prevents immunoglobulin transfer in-uteri precolostral titer >= 1:4 -- diagnostic importance |
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Porcine Parvovirus (PPV): transmission
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infection by direct transmission; intra-uterine spread to variable number of fetuses
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Porcine Parvovirus: clinical signs
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depends on stage of pregnancy:
-- <35 days: EED -regular or irregular return to estrus -- 35-70d: fetal mummification -- > 70d: sero-conversion; fetal recovery |
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Porcine Parvovirus: diagnosis
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FA detection of virus in fetal lung
HI titers - any in pre-colostral serum > 4 fold increase over 2 wks in adults |
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Porcine parvovirus: prevention
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vaccination @ 2-3 months and again@ 6 mo prebreeding
boost all sows at farrowing |
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Porcine Enterovirus: transmission and clinical signs
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very similar presentation to parvo
transmission - infection by direct transmission; intra-uterine spread to variable number of fetuses clinical signs: similar to PPV --EED, mummification, and fetal recovery |
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Porcine Enterovirus: Diagnosis
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FA in fetal mummies
virus isolation in aborted fetus and serology on pre-suckled piglets |
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Porcine Enterovirus: Prevention
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limited value due to several types involved
forced exposure - to aborted fetus and manure (to build up resistance) |
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Pseudorabies (PRV): transmission
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herpes virus; latent infection
Transmission - direct contact w/ respiratory secretions |
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Pseudorabies: clinical signs
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asymptomatic pig carries virus in "trigeminal ganglia"
when there is stress - new herd outbreak develops CNS, reproductive and respiratory signs; many develop asymptomatic disease and become latent Repro: transplacental infection -EED, mummy, and abortion |
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Pseudorabies: diagnosis
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viral isolation - brain and lung
serology |
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Pseudorabies: prevention
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depopulate and repopulate - disinfection twice in 7 day interval
leave vacant 30 days before repopulation removal of sero-positive animals offspring segregation - weaned at 17-21 days and move to off-site nursery unit; gilts from these litters can be used to repopulate cull infected adults disinfect the unit and repopulate with isolated gilts |
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Porcine respiratory and reproductive syndrome (PRRS)
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transmission: aerosol
economic importance - high morbidity |
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PRRS: clinical signs
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trans-placental infection
anorectic, depressed, febrile, late term abortion (>100d) mummification followed by stillbirths and weakened piglets respiratory signs in nursing pigs and feeder hogs |
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PRRS: diagnosis
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virus isolation from brain, lung, kidney and aborted fetus
serology |
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PRRS: prevention
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vaccine (questionable efficacy)
depopulation in nursery followed by 2 weeks vacancy repopulation w/ pigs negative for VN titers 30 d after isolation |
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Leptospirosis
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L. pomona - common
Others: L. canicola, gryppostyphosa, bratislava, and icterohemorrhagia Transmission: contact with urine and contaminated water, contact with rodents |
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Leptospirosis: clinical signs and diagnosis
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clinical signs: mid-late term abortion or still birth
Dx: serology >4 fold increase over 2 wks titer > 1:1000 previous infection IF Silver stain |
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Leptospirosis: prevention
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vaccination- weaned pigs boost @ months and twice yearly, after each farrowing
immunity is short: 3-4 months |
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Brucella suis: transmission and clinical signs
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transmission: contact w/ infected fetus, placenta, uterine discharge, and semen
clinical signs: placentitis; abortion at any stage; orchitis and epididymitis in boars- common route of infection to herd |
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Brucella suis: Dx and prevention
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Dx: culture aborted fetus, placenta, serology
Prevention: test and slaughter sero-positive; retain new born to re-populate, quarantine; depopulate |
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Epirythrozoon suis (protozoan)
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intracellular
transmission - louse (H. suis) anemia, fail to conceive, EED, abortion |
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Toxoplasma gondii (protozoan)
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transmission: cat -- oocytes - contaminated feed
intrauterine infection : abortion; stillbirth, weak pigs |
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Nutritional causes of infertility in swine
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vitamins: A, B12, E and iodine; prolonged farrowing --stillbirth
Mycotoxins - Zearalenone - prolonged gestation |
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Boars: puberty
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6 months
libido is heritable |
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Boars: spermatogenic cycle
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45 days
produces 10-15 billion sperm/day |
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Boar: anatomy
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accessory sex glands: vesicular, prostate, bulbourethral
prepuce: dorsal diverticlum corkscrew penis: average breeding time = 5 min. Breeding: 1 boar: 20 sow ratio |
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Boar: Breeding soundness exam
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semen collection- glove hand technique
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Boar: AI
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advantages: choice of superior sire, prevent disease transmission
heterospermic mating; 2 billion breeding dose breed 12 h after the onset of estrus - twice in 12 h in gilts -twice in 24 h in sows |
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Boar: infertility
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loss of libido
trauma: hemospermia testicular degeneration |
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Boar: congenital/hereditary problems
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-cryptorchidism, hernias, juvenile penis
-persistent frenulum, testicular hypoplasia - segmental aplasia of epididymis |
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Boar: infectious problems
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orchitis, epididymitis - Brucella sp.
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