Porcine Pathology Flashcards
Overfeeding of sow in gestation
- Constipation
- Predisposes to mastitis, metritis + agalactia
Farrowing complications
- Over-sized, oedematous +/- emphysematous piglet
- Needing to void bladder
- Uterine torsion - cannot correct due to long uterine horns, euth sow, recover piglets
- Uterine tear
- Prolonged farrowing
- Sick sow/dead piglets
- Retained piglet = sow paddling leg
- Metritis + endometritis
- Normal + abnormal discharges
Piglets born dead (BD)
- <10% total born, meconium staining, lungs fail to float, ‘slippers’
- Older sows
- Overfat sows
- Slow farrowings
- Excessive or inadequate manual interference
- Nervous/agitated mothers (esp gilts)
- Last piglets born
- Low birth weights
- Stress during early preg/implantation
- Disease - Leptospirosis, Parvovirus, Chlamydia, PRRS, Aujezsky’s disease
- Ill sow
- Delayed or prolonged parturition
Mummified piglets
- <2% total born
- External cause - mycotoxins
- Disease - inc in irregular returns, inc % mummified, early farrowing -> non-viable, inc NIPs (not in pig) at farrowing/empty sow
- PRRS
- Parvovirus
- Aujesky’s disease
- Mycotoxin challenge
Colostrum importance
- AB
- Cell-mediated immunity
- Hormones, GFs -> weight gain when matures
- Food = heat
- Vit A, D, E
- Laxative
- Induces pH in stomach, changing pepsinogen to pepsin
Piglets pre-disposed to disease
- Small size/large SA -> lose heat fast
- Lack of brown fat (no internal heat source)
- Little surface fat + no hair (no insulation)
- Born wet w/ birth fluids -> further chilling
Poor intakes of colostrum
- Low birth weights
- Insufficient working teats
- Stressed sow/gilt - won’t want to lie down
- Mastitis
- Chilling - too cold to move
- Cross-fostering before first suckle
- Management interventions performed too early e.g. teeth + tail
Farrowing fever
- MMA = mastitis, metritis + agalactia syndrome
- Partially created by man
- Common in smallholders
- Sow over-conditioned before farrowing then at farrowing will be off food
- Sow goes off food; may have mastitis +/- metritis + vag discharge: +/- hungry piglets
Fostering
- If teat low/non-func, piglet growth reduced/dies > 5 d
- Move before piglet is too disadvantaged
Savaging
- Nervous mother
- Often first parity gilt
- Noisy farrowing house
- Large piglets being born
- Associated w/ pain of farrowing + squealing of piglets
Sow shoulder sores
- Lesions -> bony swelling of shoulder blade, more susceptible next farrowing
- Thin sows
- Rough floors/slats
Sow not eating at farrowing
- Mastitis
- Pyrexic
- Faecal colour + consistency - ulceration, constipation
- Other CS of illness
- Vag discharge - metritis?
- Piglet condition
Weaning mortality
- 50% overlays - sow crushing piglets to death
- 25% starvation
25% other - Lame
- Scour
- Streptococcal meningitis
- Congenital deformities
- Epidemic tremor
- Savaging
Overlays
- Too cold - piglets won’t move to eat
- Poor colostrum intake
- Excess hot sow restless
- Farrowing crate too small/oversized sow
- Sow - uncomfortable/stressed/lame/shoulder sores
- Piglets hungry e.g. sow w/ mastitis - piglets always around sow
- 2y to something else e.g. lame/weak piglet not moving fast enough when sow lies down
Starvation of piglets
- Piglet moves from teat to teat in first few days then establishes on one teat, even if non-func, starvation seen from 5 d
- Mastitis in previous lactation
- Insufficient teats
- Blind teats
- Inverted nipples
- Trauma
(Runt = born small - litter size, birth weights
Starvation = normal size at birth, but then fades, especially from day 5 onward)
Blind teats
- Piglets born onto rough concrete get rubbed nipples
- Teats no longer func
Piglet diseases
- Overlays
- Starvation
- Congenital deformities
- Scour, neonatal + later
- Lameness
- Joint ill
- Nervous signs/meningitis
- Resp disease
- Skin lesion
Lame piglets
- Strep suis
- Large litters
- Low colostrum
- Rough floors; rough slats
- Injury from sow -> death, arthritis, pyaemia (septicaemia)
- Joint ill
- Trauma - iron injections
- FMDV (foot + mouth)
- SVD (swine vesicular disease)
Foot + knee damage (piglet)
- Foot v soft at birth
- Rough, wet floor surface
Sudden onset acute lame piglets/weaners
- Strep suis type 14
Lameness - joint ill (from pyaemia) (piglet)
- Dirty teeth or tail clippers
- Dirty vacc needles/contaminated bottles
- Infected navels
- Low colostrum intakes
Scouring piglets
- Poor BCS
- Hairy piglets
- Red anus + vulva
- Wet around tails
- ‘Hollow’ flanks
- Smell
- 0 - 48 h = bacterial, E. coli or clostridia - C&S
- 7 - 10 d = rotavirus, E. coli, later on coccidiosis
PEDv (porcine epidemic diarrhoea)
- Severe in N America + Asia, less virulent strains in Europe
- Explosive outbreak of watery D+ w/ reduced appetite + lethargy, sometimes V+, all ages
- High mortality (30 - 100%) in suckling piglets, all parities of sows, may be found dead before D+ noticed
- Weaned + older pigs, PED = transient + pigs recover
- ND in England
Neurological signs (piglet)
- Hypoglycaemia
- Congenital tremors
- S. suis meningitis - several strains, severity varies -> paddling, nystagmus
- ND = Aujesky’s disease, ASF, Talfan/Teschen (Teschovirus encephalomyelitis)
Skin lesions (piglet)
- Greasy pig
- Epitheliogenesis imperfecta
- Pityriasis rosea
- Abrasive necrosis
Congenital deformities (piglet)
- Splay leg
- Atresia ani
- Cleft palate
- Thickened forelegs
- Congenital tremor - okay when sleep but severe prevents suckling -> knee damage
- Hydrocephalus
- No action - euth
Splay leg
- Weak piglets
- Low birth weights
- Compounded by smooth floors
- Genetic - Landrace
- Die from starvation or overlay
Stressors at weaning
- Maternal separation
- Now social hierarchy
- New environment + temp
- Necessity to locate new feed + water sources
- Dietary change from liquid milk to solid cereal based diet
Effect of weaning stressors
- Post-weaning anorexia - maintenance energy requirements not met until 3 d post-weaning, intake dec at weaning
- Stomach less acidic, absorptive surface of gut dec, malabsorption - gut not ready for cereal digestion, protective immune factors in milk removed
- Damaged gut barrier func -> malabsorption, D+ + dehydration, gut inflam, systemic disease
Rapid growth (weaners)
- Feed efficiency declines w/ age
- Lost lean growth at this stage not regained later
- Capacity for lean growth declines w/ age - middle-aged spread
Hygiene performance
- Disease control
- Improve performance - pig sick
- Welfare - preventing harm or disease
- Carryover of disease
- Maintenance of buildings - servicing, repair, C&D
Identifying sick pig
- CS of disease - eyes, ears + nose
- Social interactions
- Eating/drinking
- Scour
- Skin colour/wounds
- Resp rate
- Lameness
- Warmth seeking
- Behaviour
- Posture
- Perineal soiling
- Swollen joint/navel
Temp effect on growth rates
- For every 1 C below lower critical temp of thermoneutral zone (between 15 - 30 C)
- Pig loses 10 - 12 g live weight gain per day
- If too warm - won’t eat as much
- Too cold - eat plenty, less energy used for growth
Development of unevenness post weaning
- Overcrowding - uneven no. sows farrowing
- Poor hygiene
- Cold
- Incorrect ration
- Poor ventilation
- Not enough feed space or hoppers not being refilled freq
- Disease
Small weaner
- Less heat production - require higher ambient temperatures
- Eat less food - need better diet
- Prone to disease
- Less able to compete
- Continue to be disadvantaged
Factors that affect feed intake (weaner)
- Blocked hoppers
- Dust
- Wet/soiled feed
- Damage to feeders
- Incorrect diet
- Water flow rates
- Ambient temp
- Health problems
Aggression (weaner)
- Social hierarchy
- Mixing pig
- Avoid vice
- Gets worse as get older
Diseases (weaners)
Factors affecting health
- Stress
- Temp
- Poor ventilation
- Incorrect diet
- Inadequate water supply
- Stocking rate
- Poor hygiene + maintenance
- Previous health problems
- Visitors/breaches in biosecurity
Post-weaning D+
- 7 - 10 d post-weaning
- E. coli infections - some scour, others -> bowel oedema
- Good piglets growing well, squeaky squeal, puffy eyes, sudden deaths
- Salmonella
- PCV-2
- Take swabs from untreated pigs for bacteriology + antimicrobial sensitivity
PMWS (post-weaning multisystemic wasting syndrome)
- PCV-2
- 30% post-weaning mort
- 3 - 4 w post-weaning
- Pigs weaning in good condition, start to lose weight -> yellow scour -> death
PMWS (post-weaning multisystemic wasting syndrome) - PME signs
- Massive H+ + oedema of mesenteric + inguinal LNs
- Yellow scour in colon
- Enlarged spleen + liver
- Lung congestion (inc coughing)
- ‘Turkey egg’ kidney = enlarged + mottled
PDNS (porcine dermatitis + nephropathy syndrome) (weaner)
- Massive dark black skin lesions
- Most affected die
- Ear tips may drop off
Meningitis (weaner)
- Most common cause = Strep suis type 2
- Sporadic cases = Glassers, consequences of pyaemia (e.g. from tail biting), salt poisoning/water deprivation, oedema disease
- Environmental conditions inc, see in spring - large temp fluctuations e.g. Autumn, high humidity, poor ventilation, overstocking
- Dx - swabs of heart blood, CSF
Meningitis CS (weaner)
- Sudden death - often don’t see any CS, just dead piglet
Neuro signs - Ataxia
- Recum
- Paddling
- Proprioceptive deficits
- Pyrexia
Systemic streptococcus suis (weaner)
- CS - systemic effects - joint swelling, lethargy, inappetence, seizure, nystagmus, sudden death
- Dx - PME = nothing, fibrin-polyserositis, endocarditis
- Microbiology - heart blood, joint fluid, meningeal swab
Disease transmission between UK farms (pigs + people transmission)
- Meningitis - streptococcus suis
- Enzootic pneumonia - mycoplasma hypopneumonia
- Blue ear - PRRS
- Influenza
- Swine dysentery
Notifiable/exotic diseases
- ASF - working its way across Europe in animals + products
- CSF
- FMDV
- PED - porcine epidemic diarrhoea
- Aujeszky’s disease - no tin UK
Porcine epidemic diarrhoea (PED)
- V pathogenic - 1 mL solution of 1 g diarrhoea in 748 gallons of water will infect a pig
Endemic diseases
- EP - mycoplasma hyponeumoniae
- PCV-2 - possible to have +ive PCR result if have vaccinated animals - don’t know if infection active + significant from PCR - cannot used for definitive Dx
- Erysipelas
- Parvovirus
- E. coli
- Clostridial disease
Serology
- PRRS
- EP (enzootic pneumonia)
- Ileitis
- Swine influenza (paired samples)
Tail biting
Housing + husbandry -> behaviour, welfare issue - when not happy, exhibit vice
- Crowded
- Temp variation
- Uneven tail dock length
- Inadequate feed or water space
- Other diseases present -> ‘grumpy’ pig
- Genotype
- Welfare regulations - must have manipulative material e.g. straw to distract/bite
- Not always to tail, can be flank/ears
Main groups of diseases
- Enteric disorders
- Resp diseases
Everything else
- Mulberry heart
- Meningitis
- Skin disorders, erysipelas
- Lameness
- Vice
- Management factors - food, water, space, ventilation, scrape through, hygiene between batches
Enteric disorders post-weaning
- Ileitis
- E. coli
- PCV2-AD
- PED
- Salmonella
- Colitis
- Brachyspira
- PMWS - post-weaning multisystemic wasting syndrome
- Swine dysentery
Scouring in older pigs
- Colitis = dietary
- Ileitis - Lawsonia intracellularis
- Salmonella
- Swine dysentery = Brachyspira hyodysenteriae
- Yersinia
- PED/TGE (transmissible gastroenteritis)
- Non-specific - Brachyspira pilosicoli, intestinal parasites
- Swine fever
Lawsonia intracellularis (ileitis)
(PIA = porcine intestinal adenomatosis)
- Endemic in UK - often just see loose faeces
Variation in CS
- Peracute = sudden death from intestinal haemorrhage, ‘Haemorrhagic enteropathy’
- Acute - magenta colour scour
- Chronic - scour
- Subclinical - poor growth
Acute ileitis
- Extensive H+ in intestine
- Difficult to distinguish between from intestinal torsion, open pig v slowly (or will inc freckles)
- If bowel wall not inflamed, check for stomach ulcer
Chronic ileitis
- Diphtheritic gut
- Enlarged mesenteric LN
- Thickened diphtheritic terminal ileum (just before joining colon)
Swine dysentery
- Brachyspira hyodysenteria
- Dysenteric scour - blood + mucous
- Massive weight loss + deaths
- High mortality if not controlled
- Deaths in sows + finishers
- DDx = acute ileitis
- CS = blood + mucus in faeces
- Dx = CS, culture - PCR
Swine dysentery vs acute ileitis
- SD in colon, not ileum
- Higher mortality
- Can affect sows
- Generally in older pigs
Why is swine dysentery on the inc?
- Biosecurity - loading ramps, clean lorries
- Wildlife - birds, foxes
- Some strains resistant to some antimicrobials
Dx approach to enteric disease
- Clinical Hx - age, stage of production, vacc, feeding Hx
- Clinical inspection - morbidity + mortality
- Investigation - faecal sampling, swabs, pooled faeces samples (untreated pigs); PME - gross appearance, intestinal samples, histology sections; submit carcase to APHA
- Tx + control options - group/indiv; in feed/water/injection; vacc; nutritional manipulation
- Public health implications - zoonotic e.g. Salmonella
Respiratory diseases
- EP - enzootic pneumonia - mycoplasma hyopneumoniae
- APP = Actinobacillus pleuropneumonia
- PRRS = porcine reproductive + respiratory syndrome
- Glassers = Glaesserella parasuis
- SI = swine influenza
- AR = atrophic rhinitis - pasteurella + bordetella
- PMWS - porcine circovirus type 2
- Coronavirus
- Pasteurella/Mannheimia
- Inclusion body rhinintis
Respiratory CS
- Coughing/sneezing
- Inc resp effort = really struggling
- Nasal/ocular discharge
- Dec appetite
- Condition loss
- Repro effects - PRRS, flu in breeding stocks
- Death
Resp Dx
- Blood samples - serology, PCR
- Nasal/tonsillar swabs - flu
- Upper tracheal
- PME - lung, histopath
Enzootic pneumonia (EP) - Mycoplasma hyopneumoniae
- Consolidation of tips of apical + cardiac lobes
- Dec daily average gain + FCR
- Coughing, esp older pigs, pale pigs, inc mortality
Enzootic pneumonia (EP) - Mycoplasma hyopneumoniae - abattoir score of lungs
- Apical (cranial) = 10 x 2
- Cardiac (middle) = 10 x 2
- Diaphragmatic (caudal) = 5 x 2
- Intermediate (accessory) = 5 x 1 (RHS)
- Max possible score = 55
APP - actinobacillus pleuropneumonia
- Lesions in centre of diaphragmatic lobe
- Area of intense H+ + Overlying pleurisy
- Looks like ‘liver’
- Deep abdo cough
- Reduced growth rates
- Sudden deaths, sometimes coughing
- Chronic, ‘heavy’ coughing + reduced growth + some cases, sudden death
- 15 main serotypes, producing 3 diff toxins
- Infection from dam - MDA last 5 - 5 w, 10 w w/ vacc
Glassers (G. parasuis)
- Pericarditis + pleurisy (inflam of pleura)
- Polserositis - can affect all serous surfaces = joints, meninges
- Common infection
- Often occurs following immune suppression e.g. PRRS or PMWS
- If severe outbreak - check for predisposing factors - PRRS or PCV2
Atrophic rhinitis
- Nasal distortion - seen later in life
- Bordetella damages nasal mem allowing toxigenic Pasteurella to enter + damage turbinates
- Piglet infection -> sneezing
- Tear staining
PRRS = porcine respiratory and reproductive disease
- ‘Blue ear’ seen in initial outbreak - ear tip + snout necrosis
- Acute outbreak - sick sows, abortions, deaths, v high piglet mortality, inc in other resp diseases
- Endemic disease - pneumonia w/ lung congestion + oedema, monitor by serology, sometimes see blue ears
- Predispose to other diseases e.g. piglet scour
Swine flu
- First outbreak on farm
- All cough - sows, piglets, growers
- Finishers stop eating for 1 - 2 w
- Some deaths
- Endemics - waves of coughing in finishers + inc mortality, severity depends on strain, ‘blue flu’ = PRRS + flu
PRDC (porcine respiratory disease complex)
Mixed infection
- PRRSv coronavirus
- Swine influenza virus
- Circovirus (PCV2)
- Mycoplasma hyponeumoniae
- Haemophilus parasuis
- Streptococcus suis
- Bordetella bronchiseptica
- Actinobacillus suis
- Actinobacillus pleuropneumoniae
Dx approach to resp disease
- Clinical Hx - age, stage of production, source vacc Hx, health status
- Clinical inspection - morbidity + mortality, CS
- Investigation - serology if indicated; PME, gross path, histopath, sampling from lower RT; nasal, pharyngeal, tracheal swabs
- DDx
- Tx + control options - group/indiv; in feed/water/injection; vacc; nutritional manipulation
- Public health implications - zoonotic
Nasal swabs
- Virus isolation for flu
Pharyngeal/tracheal swabs
- EP (enzootic pneumonia) by PCR on throat swabs, early stages of outbreak for positive result
Oral fluids
- PRRS
- Ropes hung in pens, pigs chew
- Fluids squeezed out of ropes into tube -> tested via PCR
Rectal prolapse
- Constipation = low fibre
- ‘Grist’ of food too fine
- Over-crowding
- Inc pressure e.g. fighting
- Excess coughing
- Scouring + rectal irritation due to medication, coughing etc
- Mycotoxins - DON = deoxynivalenol
- Excessive lysine (> 20% above target, target = 1.25%)
Skin lesions/changes of pigs
- Mange
- FMDV
- Lice
- CSF
- PDNS
- Greasy pig
- ASF
- Erysipelas
- Flank biting
- Tail biting + vulva biting
- Fighting Ear tip necrosis
- Hairy coat = sick/cold pig
- Pig pox
- Ringworm
- Sun burn
- Straw rash
- Sow shoulder sores
- Epitheliogenesis imperfecta
Erysipelas (Erysipelothrix rhusiopathiae)
- Skin ‘diamonds’, may scab later, sometimes skin lesions scab off
- Pyrexia
- Inappetence
- Reduced fertility in sows
- May get endocarditis + joint lesions
Greasy pig
- = Exudative epidermatitis due to Staphy hyicus
- Weaners + growers
- Dermatitis
- Poor ventilation, damp conditions, fighting, skin damage e.g. mange
- High suckling losses - esp gilt litters
Ascarids - milk spot
- SI roundworm
- Difficult to eradicate in continuous flow scrape-through system
- Milk spot = exposure in previous 6 w
- Can cause total obstruction of SI in weaners/growers
- Lesion extended into substance of liver, no. milk spots per affected liver = indicator of severity
Hernias
- Scrotal + Umbilical
- Genetic
- Umbilical = environmental influence
- Rare to Tx
- Housed on straw - some regress - gut fibre content inc
- Growth rate poor, sell early
- May need to send FCI (food chain info) to abattoir
- If skin ulcerated, unfit for transport, welfare prosecution
Mycoplasma arthritis
- M. hyosynoviae
- Infection from dam to piglet; carried by piglet to finisher weight
- Onset disease associated w/ stress - e.g. weighing prior to sale, mixing, transport of gilts
- Sudden onset of acute lameness - whole leg held, if both hind legs, then reluctant to stand, pyrexia - sometimes hock swellings
Kyphosis
- Congenital + progressive
- Leads to depressed growth
- Hereditary - carefully monitor gilts
- Slaughter early
Anaesthesia
- Sx - e.g. vasectomy, castration
- Minor Sx - sitch-up
- Management procedures - foot trimming, detusking
Sedation
- Limit savaging at farrowing
- Prevent fighting
Euthanasia - legal
- To protect animal welfare
- w/o causing unnecessary suffering
- Blunt force trauma = neonates only
Mechanical euthanasia
- Quick + reasonably clean, small amount of restraint
- Limited stress
- Agonal movement
- Can appear violent
- Human stunners = not killers - must be backed up by destruction of the brain stem (pitching) or bleeding
- Massive, sudden inc in pressure in skull, followed by immediate dec of equal magnitude -> total brain dysfunction
- Restraint necessary
Physical signs of effective stun
- Animal collapses immediately + stops breathing
- Front legs + neck extended w/ hind legs flexed into lower abdo
- Fixed glazed expression in eyes
- No corneal reflex
- Relaxed lower jaw w/ tongue hanging out
Ineffective stun - return to consciousness signs
- Resumption of rhythmic breathing
- Stun again immediately
Firearms considerations
- Size + age of animal
- Location
- Accessibility of target area
- Presence of onlookers
- What is safe + legal
- Operator competence
Blunt trauma
- Only suitable for small piglets
- Manual or mechanical
- Must be done w/ absolute force + confidence -> effective
Transmission of disease
- Pigs
- People - Stockman, Contractors, Vets, Lorry Driver
- Vehicles – Pig Lorries, Feed, Deadstock, Visitors, Tractors, Postman etc.
- Wildlife – Rodents, Birds (Including migratory!)
- Feed
- Human food – The Ham Sandwich Theory! - no pork products allowed
- Semen - monitor boars closely
- Airborne - PRRS, mycoplasma hyopneumoniae
Excessive mounting
- Puberty/sexual maturity
- Excessive sexual behaviour
- Biting of penis
Mulberry heart disease
- Sudden deaths
- Rapidly growing pig
- Vit E deficiency + selenium deficiency in diet
- Dx: enlarged heart with excess pericardial fluid, enlarged liver, fibrin tags in abdomen
Contraindications of captive bolt stunning
- Older animals + sows + boars - thicker bone
- Vietnamese pot-bellied pig - massive plate of bone
- Consider shotgun
Gilts
- Needed to maintain herd size
- Planned introduction
- Replacement rate (40-60%)
- Disease
- Depopulation /partial /total
- Increased culls
- Fertility problems
Replacement gilts - bought in
- Disease risk - macro diseases: PRRS, EP, S. suis, swine dysentery
- Herd stability - change to existing microflora
- Increased speed of genetic
improvement - don’t have to wait for own gilts to be reared - Fewer economic constraints on rearing herd
- Already selected - for KPIs
Replacement gilts - home-reared
- Less risk of introducing disease
- Genetic lag
- Formal breeding programme needed
- Alternative growing stream
- Numbers required
- Selection
Health status (gilt)
- High health vs conventional
- Equivalence or higher status needed for incoming animals - PRRS, mycoplasma - EP, mange, strep. suis - high health should be negative
- Consider vaccination pre- and post-delivery
- Isolation requirements - min 30 d
- Acclimation
- Don’t buy in from poorer herd status
Isolation (gilt)
- Preventing introduction of new pathogens to the recipient herd
- Isolated for at least 28 d
- Isolation managed as AIAO
- Allows pre-entry diagnostics, serology, vaccination
- Monitoring clinical signs
- Biosecurity
Health acclimation (gilt)
- Slowly expose incoming gilts to the organisms and pathogens existing
in the recipient herd - Giving gilts time to establish immunity
- Too little – inadequate immunity, will affect productivity
- Too much – may see clinical disease and death, will affect productivity
- Combination – natural exposure and vaccination
- Exposure – direct or indirect contact
Vaccination (gilt)
- Vary depending on health status
- Parvovirus and erysipelas
vaccination essential - Consider PRRS, EP, PCV2, HPS (Glassers/haemophilus parasuis), Ileitis
Exposure (to pathogens specific to farm in gilts)
- Not be earlier than 20 - 22 weeks of age
- Not within 3 weeks of breeding
- Feedback not permitted
- Controlled exposure - 3 x week for 3 weeks
Gilt eligibility - factors
- Maximise feed intake prior to first service - essential for growth + meeting reproductive potential, avoid feed restrictions while growing
- BW at first service - reflects growth + body maturity - 136 - 145 kg, approx 200 d
- Immunity - solid acclimation - don’t serve within 3 w of last vacc/any other health procedure
- Selection - approx 90%
- Age at first service = 200 - 230 d on second heat
Gilt selection
- Good feet and legs
- At least 14 functional teats
- Mature vulva
- Good temperament
- Avoid deformity e.g. kyphosis or where litter mates show signs of hernia etc.
- Gilt fertility performance is improved by increased back fat - take gilts off high lysine finisher food by 70 - 80kg and put onto sow food + don’t overfeed, can lead to leg problems
- Move them near to boar and record heats
- Serve at second or third heat
- Give gilts plenty of human contact, handling etc
Teat selection
- Minimum 14, preferably 16 teats
- Check for damaged teats - rubbed when piglets; inverted nipples
- Evenly spaced
- Close to mid-line, not too ‘splayed’
Vulval maturity (gilt)
Boar exposure
- Daily exposure to a mature boar – or can use a vasectomised boar
- Do not expose prepubertal gilts to
boar: habituation problem - Daily boar exposure at/after 24
weeks - Supervise to avoid accidental
mating or injury
Anoestrus (gilt)
- Age - immature/heavy enough
- Poor environment
- Bullying/stress
- Disease
- Lameness
- No boar presence
- Poor light
- Nutrition
- Sunburn
- Pregnant
Gilt, clinical issues - reproduction conditions
- Parvovirus
- SMEDI (stillbirth, mummification, embryonic death + infertility)
- PRRS
- ND: Aujeszky’s disease, CSF, ASF, Brucellosis
- Leptospirosis
- Listeriosis
- Erysipelas
- Mycotoxins
- Vitamin deficiency (A,E, biotin)
- Cystitis and pyelonephritis
Most common cause of culling sows early
- Reproductive failure
- Lameness + leg problems
- E.g. Osteochondrosis
Production cycle + key parameters
Farrow
- 12.71 born alive (13.80)
- 0.58 born dead (<10%)
- <12.4 % loss to weaning (10.59)
- 10.65 weaned (12.33)
- 24.12 wpspy (weaned per sale per year) (29.33)
- Wean at 28 d -> 2.44 litters per sow per year
- Heat 4 - 6 d after weaning
- 21d cycle length
- 115 d pregnancy (3m, 3w, 3d)
- Sell at 22 weeks = 155 d at 110 kg = 700 g/day
- Serve 10 - 15% more sows than your target farrowings to maintain even no. farrowing
- Need sows to come on heat as batch so they farrow in short time scale
Weaning to service (WTS) interval factors
- Stressful at weaning
- BCS of sows + gilts
- Length of suckling period
-No. + weight of piglets - Inappropriate management at weaning
- Aim for 5 - 6 d
- Empty days cost money - inc WTS interval will affect production, dec time = inc production
Dec weaning to service interval
- Excessive weight loss during lactation
- Short suckling period
- Extended suckling period
- Few piglets of small piglets
- Large litter of big piglets
- Small litter of big piglets
- Large litter of small piglets
- Discharge / MMA (mastitis, metritis, agalactia) in farrowing house
Weaning age
- Consistent
- Requirement for 28 d (can be 21 d w/ suitable accomm)
Lactation length factors
- Sow condition and feeding
- Size and weight of weaners
- Future farrowing space requirements
- Culling policy
- Fostering techniques
Fertility KPI
- WPSPY/LPSPY
- 115 d gestation
- 5 d wean to service
- 4 d (= 20% of 21 d) for repeat serves/returns
- 10 d for deaths, culls etc of preg sows
- = 134 d per cycle / 2.72 litters/sow/year
- Prolonged weaning + high % returns = reduced litters/sow/year
Average - 2.2 - 2.3 LPSPY = farrowing index
- 85 - 90% sows farrow = farrowing index
Fertilisation
- Fertilisation in oviduct
- Move to uterus at approx day 4
- Then migrate along uterus at day 7 - 10
- Placenta elongates at day 12 – 14 and attaches to uterine wall
- By 28 - 30 days, pregnancy is reasonably firmly established
Early preg/losses %
- 20 eggs produced = 100%
- 18 eggs fertilised = 90%
- 15 embryos at 21 d = 75%
- 13 foetuses at term = 65%
- 12 born alive = 60%
Signs of heat - when stimulated by boar
- Ears prick
- Sharp grunt
- Enlarged + red + moist vulva
- Mounting activity of each other
- Spot on = apply back pressure + won’t move
Timing of mating
AI technique
- Ovulation occurs 2/3rds through oestrous, 36 - 44 hr after onset of heat
- Need to AI before ovulation, if 2x/day detection, OK to miss first heat
- Incorrect timing of AI affects litter size
- Back pressure is the best sign of heat
- AI twice per heat, or 3x if prolonged heat
- Longer heat (and more fertile) if short W-S interval
- Conversely shorter heat if long W-S interval, so AI at onset of heat
- Better heats in spring than autumn
Semen care
- Gently mix twice daily - nourish semen
- Store at 17 C
- Make sure that temp does not fluctuate when you take semen to sow
- Clean DRY catheters
- Some farms collect semen, dilute and AI
Boar fertility factors
- Nutrition
- Health - flu, PRRS
- Housing
- Usage
- Legs - mounting
- Flooring
- Condition
Boar facts/KPI
- Puberty at ~5 months
- Fertility improves by around 7 - 8 months
- Ideally start working by 12 months
- Working patterns can vary – natural service vs stud
- Sperm takes 6 weeks to produce
- Each ejaculate is ~250 mL in three fractions
- Usually sterile – contamination from preputial sac
- Ejaculation takes around 15 - 20 minutes
Failure in libido (boar)
- Health - febrile, lame, pain, clinically well?
- Management - overworked, unsuitable matings, stockmanship
- Environment - slippery floors, unfamiliar noise
- Other - frustration, mycotoxins, presence/absence of other boars
Boar bleeding after service
- Torn penile frenulum - if persistent, can break or rip
- Blood -> reduced semen fertility
- More common in outdoor units - esp, if ground is muddy + uneven - boar gets pushed off sow in group situation
- Often recurs
Boar consideration
- Other boars present / not present? - - Familiar surroundings
- Routine / stockman
- Patience
- Boar grouping/rotation
- Supervision with young boars/gilts
- Size mis-match
Increased returns
- Regular = conception failure - 21 d, failure to identify
- Irregular = embryo death (or
served when not on heat) e.g. abortion, something not observed, record keeping sig - Check boar effect
- ‘Autumn infertility’ = common for
decreased fertility as daylight
decreases, so check lighting
pattern
Reproductive failure
- Parvovirus
- PRRS
- Leptospirosis
- Erysipelas
- Cystitis and pyelonephritis
- Influenza
- CSF / ASF / Brucellosis / Aujezsky’s Disease
- Nutritional deficiencies
- Mycotoxins
- Lameness
- Management
Conception - boar factors
- Over/under work
- Age/condition/weight
- Mismatched sizes
- Mating area
- Semen storage
- AI technique
Conception - sow/gilt factors
- Timing of service
- Age/condition/weight
- Mating area
- Feed levels ‘flushing’
- Strong oestrus
Service to 21 d
- Low stress
- Critical time for fertilised ova to adhere to uterine wall ‘implantation’
- Approx 2 kg
21 d to 90 d prior to farrowing
- PD
- Moving/mixing/re-grouping
- Usually restricted
- Depends on condition
- ~2kg
90 d to exit for farrowing
- Visual check for health
- Increase feed for gilts and thin sows
- 2.5 - 2.7 kg
- Maintain feed at a lower level for fat sows and gilts
- ~2kg
Pregnancy
- Vacc 3 - 4 w pre-farrowing
Infertility - non-infectious
- Failure to conceive
- Management
- Stress - timing of insemination
- Nutrition
- Failure to identify NIP (not in pig), poor PD ability
Infertility - infectious causes
- PRRS
- Erysipelas
- Parvovirus
- Leptospirosis
- SIV
- PCV-2
Infertility - PRRS
- PRRS herd status
- Timing of infection, seroconversion
- Transient pyrexia, laboured breathing, anorexia
- Abortion – RTS, early farrowings
- Increased stillbirths, mummified piglets, increased mortality in piglets
- Agalactia, decreased appetite, anoestrus
- Economically sig
NIP - not in pig sows - infertility
- Should only be 1 – 2 % - records essential
- Failure to check for returns at 18 - 30 days (Often boar running with or
adjacent to sows) - Failure to pregnancy check
- Abortions
- Simply never served - e.g. just left with boar and hope
- Make sure sows are ear tagged and checked at due date, otherwise they may simply stay in dry sow yard
Abortion - litters born before term
- Fever - most diseases cause
- PRRS
- Parvovirus
- Circovirus
- Mycotoxins - nutritional
- Erysipelas
- Leptospirosis
- Notifiables - abortion storm
- Management factors
- Environmental factors
Sow replacement rate
- Replace at least 45 % of herd per year
- 20% + of each farrowing may be gilts
- 100 sow herd needs 45 gilts per year introduced into the herd
- Purchase or home rear
- Purchase = disease risk, mitigated as far as possible
- Home rear - uneven supply and dam line pigs often do not compete with meat line breeds
- Look ahead at farrowings, if you see a reduced number of sows due to farrow in any month, then need to bring in gilts
- Target cull after 6th parity (beyond this milking ability drops, so although numbers born may be OK, numbers weaned will be poorer)
Health problems in dry sow period
- Anoestrus
- Coughing
- Diarrhoea
- Haemorrhage
- Lameness
- Mastitis
- Inappetance
- Pyelonephritis - inc in warmer months, cloudy urine + vag discharge, not drinking as much
- Skin diseases
- Loss of condition
- Vomiting
- Abortion
Diseases associated w/ feed + nutrition
- Abortion
- Colitis
- Fractures / OCD / osteoporosis
- Mulberry heart disease
- Rectal prolapse
- Respiratory disease
- Gastric torsions
- MMA - mastitis, metritis, agalactia
- Water deprivation / salt poisoning Anaemia Diarrhoea Ulceration Mycotoxicosis Reproductive problems Obesity Starvation
Why vaccs are not infallible
- Incorrect diagnosis - wrong disease
- Incorrect timing of administration, e.g. just 7 d pre-farrowing
- Contamination – needle left in bottle
- Poor storage – vaccine left out of fridge/storage
- Poor piglet colostrum intakes – weak, chilling, low birth weights,
sow mastitis - Sow immunosuppression – cold, hunger, PRRS, flu, other intercurrent diseases,
- Vaccine site abscesses
- Incorrect administration e.g. given IM not SC
Mastitis post-weaning
- Reduces milking ability next litter
- Sows running milk
- Wet, dirty floors
- Slippery floors Failure to clean out daily
- Overcrowded
- Mouldy straw bedding
Vices in breeding sows – vulval biting
- More common in late preg sow w/ enlarged vulva
- Overfat sows/unease
- Consider welfare of group - if unhappy sows, more likely to bite:
- Overcrowded
- Continual mixing of sows =
dynamic groups - Uncomfortable housing, especially too hot
- Inadequate feeding or drinking space
- Rogue sow, temperament
Mange - Sarcoptes scabei var suis
- Reduced weight gain; rubbing/itching sows damages buildings; reduced carcase value if skin has to be removed
- Dx - thickening of skin around neck; white crusts in ear – black discharge is normal; red scabs on inside of boar legs; skin scrape and microscopy
Lice – Haematopinus suis
- Uncommon in commercial herds
- Dx - 5 mm - can be seen moving around by naked eye
- Esp. visible on neck
Vaginal/cervical prolapse
- Cervical/Vaginal most common in breeding sows
Uterine (+ rectal) prolapse
- More likely in older sows
- Large litters may contribute
Sudden deaths in sows
- Usually summer - autumn
- Gastric torsion
- Clostridial infections
- Pyelonephritis
- Stomach ulcers
- PMS not common - need proper handler, v heavy animal
Sudden death - gastric torsion
- Massively bloated carcase
- Gross dilation of stomach
- Try to find torsion at root
- Often sow in farrowing house ate, okay in the morning, dead by afternoon
- Should be uncommon
- May be combined w/ splenic torsion
- Usually lactating sows
- Irregular feeding intervals
- Excess excitement
Clostridium novyi (oedematiens)
- Straw-bedded systems, dirty straw or soil
- Usually sporadic cases
- Can get regular deaths when
introduced into risk area - PME - care, older carcasses can look
like this from normal decomposition, so it must be fresh, typical ‘aero chocolate’ liver = fizzy liver§; blood throughout carcass; haemorrhages in heart and muscle
Cystitis and pyelonephritis
- H+ on bladder wall
- Cystitis common, and as the bladder valve becomes eroded, can get ascending infection to kidney
- Water deprivation: ureate crystals on vulva
- Blood in urine is cystitis/pyelonephritis
- (Pus is more likely to be vaginitis)
Stomach ulcers
- Sudden death
- Pale carcass
- Associated with ‘grist’ of food
- Usually only sporadic cases
- Can have outbreaks in growers and finishers
Health problems in dry sow period
- Anoestrus
- Coughing
- Diarrhoea
- Haemorrhage
- Lameness
- Mastitis
- Inappetance
- Pyelonephritis
- Skin diseases
- Loss of condition
- Vomiting
- Abortion
Common causes of dietary problems in pigs
- Salt poisoning + water deprivation - common in pet/backyard chickens - risks of fed illegal household waste + imbalances in diet
- Rickets - hypocalcaemia, hypophosphataemia or hypovitaminosis D
- Iron deficiency anaemia - all commercial piglets given iron injections if live outside
- Selenium / Vit E deficiency -> mulberry heart disease
Vitamin E deficiency
- Complex deficiency - > major CS relating to effects on energy
- Hepatocytes + muscle cells most in heart + skeleton affected
- Syndrome develops as result of CHF coupled w/ hydropericardium
Salt poisoning / water deprivation
- CS - inappetence, ataxia, seizure, lethargy + unwilling to stand, depression
- Illegal diet - unbalanced + high in salt e.g. food waste (pet pigs)
- Acute onset progressive neurological