Pig reproduction and infertility 1+2 Flashcards
What is the pigs/sow/year target?
22-26, perhaps 28 is target (Depends on type of unit); consists of number of litters/year (aim for 2-2-2.4, some farms will do 2.6), litter size (12-14) and pre-weaning mortality (<10%).
When do gilts reach puberty?
6-8 months old, need to achieve a minimum weight of 120 kg
When do you first mate a gilt?
2nd or 3rd oestrous (if you wait for a later litter, you tend to have a slightly larger litter size, 3rd is optimal)
How long is the lactation?
28 days (legal requirement, if you can fulfil certain criteria, you can wean earlier, perhaps 3 weeks).
What is the WOI?
3-5 days later. WOI = weaning to oestrous interval
When are sows culled?
Culled = after 6 litters (some companies beginning to say their sows can last 8 litters)
What is the MRP sign in pigs?
Oestradiol from the piglet
When does a gilt/sow ovulate?
Ovulates 2/3 of the way through oestrous (48-72 hours).
How do you induced farrowing?
Prostaglandin and oxytocin, work out farm gestation length (2-3 days before expected farrowing, not before otherwise you induce abortion and have dead piglets)
Define stillbirth
some farmers say anything that dies in first 24 hours is stillbirths when it is actually a neonatal death – bear this in mind when investigating farm records. Vet definition tends to be an animal that is not born alive/never lived outside the sow. Ask for definitions of farm’s measurements.
What is a mummified foetus?
don’t macerate because it is a sterile environment, leathery – water absorbed around them, there can be an infectious cause for this, ok to have the odd one of these but no more
What do regular and irregular returns to oestrous suggest?
regular – an indicator of fertilisation problem such as boar problem
irregular - management problem such as incorrect AI timing OR early embryonic loss
What is an average cull rate?
40% sows/year
What proportion of abortions have an infectious origin?
30-40%
What is suggested by mummified foetuses/stillbirths/ weak pigs of all one size?
there has been a single insult to the uterine environment (stress, fever)
What is suggested by mummified foetuses/stillbirths/ weak pigs of differing sizes?
consider this prolonged damage to foetuses. Think infectious causes – commonly viral – parvo, PRRS and CSF etc. (e.g. virus that infects the foetuses but doesn’t give the sow a fever)
List common (4) and uncommon (3) infectious causes of abortion.
o Commonly: parvovirus, PRRS, leptospirosis, erysipelas
o Uncommon but severe: Aujeszky’s, ASF, CSF
List the marker stages of gestation
o < 35 days of gestation – most absorbed
o 35-40 days – ossification begins
o Foetus dying > 35 days – mummified foetuses through to stillborn piglets (aborted at any stage)
o 70 days foetus immunocompetent, look for evidence of an infectious cause
o Full term at 112-116 days
List non-infectious causes of abortion
o Husbandry and management – stockman, hygiene, policies (age structure of the herd)
o Environment – season, heat stress.
o Genetics – parental/ progeny
o Nutrition - micronutrient deficiencies (Vit E and A)
o Toxic agents - misuse of hormonal drugs, chemicals (teratogens in hemlock), mycotoxins (i.e. Zearalenone)
Define SMEDI. Cause?
Stillbirth mummification, embryonic death infertility
Majority of these are caused by porcine parvovirus, (porcine enteroviruses are less frequently implicated)
Classical signs of SMEDI
Full term litter consisting of small mummified foetuses, full grown stillborn, live weakly piglets, ***RARELY CAUSES ABORTION
Transmission - SMEDI - 2
oronasal and venereal
Treatment - SMEDI
none
Control - SMEDI
vaccination is available and widely practised. Vaccinate 8 weeks before service on first occasion and 2 weeks before for subsequent boosters. It is actually a good thing to have a few cases (but not too many) of mummified foetuses on a farm because it shows the virus is still circulating and that the vaccine is working. Manufacturers say you need to vaccinate before serving, but you don’t need to do this.
Causes of sequential embryonic death
usually viral.
PRRS,
Swine influenza virus (SIV),
erysipelas (skin diamonds, placental vasculitis), leptospirosis (debate over importance),
PCV-2 (unknown role in sow reproductive performance).
NOTIFIABLES – AD, CSF, ASF.
What was the original name for PRRS?
Blue ear disease
Clinical signs - PRRS
reproductive losses, increased pre-weaning mortality, severe respiratory effort in neonates (thumps), blue extremities such as ears (<1% cases, not pathognomic), flu-like signs in older pigs. Immunosuppressed animals are very susceptible to many secondary pathogens.
Control - PRRS
originally notifiable, now reported throughout the UK, vaccine available since 2001. Vaccination against PRRS (when present on farm) has decreased mortality seen with PMWS.
Clinical signs - leptospirosis
most commonly abortion and reproductive failure
Diagnosis - leptospirosis
serology, dark ground microscopy, FAT
Treatment - leptospirosis
AB medication (Streptomycin, TCs). In theory the whole herd should be treated at one time, this rarely happens. Recent moves towards the use of cattle lepto vaccines in pigs.
What are pigs vaccinated against?
parvovirus for reproductive herds, erysipelas – definitely for outdoor units, PCV-2
How do you estimate the gestation length with a foetus?
= 21 + (3 x crown/rump length (cm)
How does infection in utero affect piglets?
causes foetuses to die at different gestational ages
When is the foetus immunocompentent?
By day 70 gestation
What should foetal fluids be tested for?
parvovirus Ab, Leptospira bratislava Ab and swine influenza (new serotypes?). Also can do antigen detection tests (parvo and lepto).
What does a VLA Pig Abortio Kit allow you to test for?
swine influenza, erysipelas, parvovirus, PRRS, leptospira
Treatment - vaginal prolapse
replace and hold in place with purse string suture or Buhner suture. Use ABs and NSAIDs to reduce infection and swelling
Causes of swollen/damaged vulva
May follow vulva biting, trauma related to dystocia, farrowing crate injuries (if too small), zearelenone toxicity (oestrogenic, tends to be a herd problem
What does brown staining of the trachea indicate?
meconium lost during parturition and the pig has inhaled it. Suggests piglet died during parturition
When does piglet fostering need to be done?
within first 24 hours
What is the most common cause of death in piglets?
crushign
How can piglet birth weights affect mortality?
birth weights <0.75kg are unlikely to live
What is ‘splayleg’ in piglets?
congenital abnormality: affected piglets do the splits with their back legs. Considered a muscle weakness problem in adductor muscles in heavy male piglets.
What is epitheliogenesis imperfecta?
raw patches of flesh with skin curled up at the edges on new-born piglets. Piglets may die or recover. Must be differentiated from other pig wounds. Possibly inherited so use different boar on sow at next mating.
How do you diagnose primary uterine inertia?
DDx?
absence of straining, cervix is dilated, no obstruction present, lack of uterine tone.
DDx: secondary uterine inertia
Treatment - primary uterine inertia
assist at farrowing, oxytocin, small amounts regularly, not a big bolus, 2-5 international units (0.2-0.5ml), IM, give at 30 minutes interval. If toxaemia/infection present give ABs and/or NSAID. Check for blockage at the bifurcation.
Cause of secondary uterine inertia
obstruction caused by: malpresentation, 2 foetuses together, distended bladder, vaginal prolapse, vulval haematoma.
Treatment - secondary uterine inertia
correct malpresentation, manually deliver foetus, once obstruction is relieved give 1-5 IU of oxytocin IM. CS are performed? Economically justified.
Treatment - uterine prolapse
euthanize or immediate on-farm slaughter. Cross-foster piglets.
Causes - downer sow
Many causes, include: lactation osteoporosis femur/hip fracture, muscle weakness, apophysiolysis (separation of epiphysis from the bone shaft?), rupture of lesser trochanter
Treatment - downer sow
cull if fractures present, move onto deep straw or put straw rubber matting under sow to prevent sores, encourage movement a few times a day
Clinical signs - hyocalcaemia
recumbency, coma, death, eclampsic form with convulsions, rapid response to calcium borogluconate IV/SC
What are the main causes of agalactia? 4
Failure to let milk down
Hot painful immature glands with normal milk
Ergot poisoning
Water deprivation
Treatment agalactia - failure to let milk down
inject oxytocin (10IU) once
Treatment agalactia - Hot painful immature glands with normal milk
NSAIDs. Repeated injections (every 3 hours). Can take > 3 days to resolve so will need to supplement affected litters.
How much water do sows need a day?
25-40L
Causal agents - coliform mastitis
: coliform bacteria, Pseudomonas, Enterobacter, Citrobacter and Morganella. Most commonly E.coli or Klebsiella. Also environmental pathogens possible
Treatment - coliform mastitis
AB (potentiated sulphonamides) required for at least 305 days, NSAIDs, oxytocin encourages milk flow. Supply supplementary feeding for the surviving litter.
Cause - pyogenic mastitis
Stapylococci or Streptococci (also Actinomyces)
Clinical signs - urinary tract disease - pyelonephritis / cystitis
haematuria, pyrexia, bloody vulval discharge, fibrin, pus and blood when urinating, inappetence, depression, death.
Cause - urinary tract disease - pyelonephritis / cystitis
the bacterium Actinobaculum suis found in the prepuce of most boars > 10 weeks old (previously named Eubacterium suis, Actinomyces suis, Corynebacterium suis).
