THE DANISH SPF SYSTEM & DIFFERENT DISEASE ELIMINATION PROCEDURES

Transcription

1 Poul Baekbo DVM, PhD, Dipl. ECPHM SEGES, Danish Pig Research Centre THE DANISH SPF SYSTEM & DIFFERENT DISEASE ELIMINATION PROCEDURES Canada 26th of October 2018

2 million pigs produced per year in Denmark 17 million slaughtered (export of 2 million tons) Export of 14 million weaners

3 Danish LEGO

4 Plan for presentation Poul Baekbo and SEGES Danish pig production The Danish SPF system Elimination by Partiel Depopulation 1. PRRS 2. APP Conclusions

5 Who is Poul Baekbo? 5.. Veterinarian in 1982 (DVM) PhD 1989 Dipl. ECPHM years in general practice at the countryside 6 years at the Veterinary University in Copenhagen Research in diseases of pigs (PhD) and horses 28 years in pig disease R&D for the pig industry

6 What is SEGES? 6.. The farmers own Advisory & Research Organisation About 650 employees in SEGES Annual turnover is one billion DKK=133 million EURO Part of the Danish Agriculture & Food Council The Pig Research Centre is one of the units of SEGES

7 Danish Pig Research Centre Financed by Danish pig farmers Responsible for research and knowledge transfer to the Danish pig industry Trials for 20 million Euro per year (100 R&D persons) Operating in 200 commercial farms Field trials

8 Areas of RESEARCH 29. oktober 2018 Fokus on APPLIED research Taking New Technologies from basic research into the field All relevant areas for the pig producer Genetics & breeding Nutrition Housing conditions Pig health & veterinary matters Environment Economy

9 Plan for presentation Poul Baekbo and SEGES Danish pig production The Danish SPF system Elimination by Partiel Depopulation 1. PRRS 2. APP Conclusions

10 The Danish Pork Industry

11 Structure of Danish pig farms (2017) Family farms Average size 800 sows Total of 3226 farms Farrow-to-grower/finish 37 % Farrow-to-wean 15 % Weaner 8 % Growers & finishers 40 % 52% with sows

12 Productivity in Danish pig production (2016) All farms The top 25 % of the farms Live born per sow Weaned pigs per sow per year Daily gain, weaners 444 g/day 486 g/day Daily gain, finishers 950 g/day 1002 g/day Mortality, weaners 3.1% 2.8% Mortality, finishers 3.4% 2.7%

13 Weaned pigs per Sow/year The top 25% The mean of all herds Sow herds, weaned pigs per sow/year, average Sow herds, weaned pigs per sow/year, best 25 %

14 Health status in Denmark F&M disease 1983 Classical swine fever 1933 Eradicated Pseudorabies 1991 African swine fever Never recorded TGE/PED Never recorded Salmonella choleraesuis Sporadic

15 Main enzootic infections Swine influenza (H2N1, H3N2, H3N1) PRRS (EU, US) PCV2 (PMWS) Porcine parvovirus Mycoplasma hyopneumoniae Actinobacillus pleuropneumoniae Toxigenic Pasteurella multocida Brachyspira hyodysenteriae & pilosicoli Lawsonia intracellularis E.coli

16 Major challenges in Danish pig production Pig health High health & producitivity Demand for new vaccines & production methods The society (the human invironment) Antimicrobial resistance (low use of antibiotics) Animal welfare Food safety The nature (environment & smell)

17 Plan for presentation Poul Baekbo and SEGES Danish pig production The Danish SPF system Elimination by Partiel Depopulation 1. PRRS 2. APP Conclusions

18 Elimination of diseases Three different principles 1. Total depop/repop (SPF system) 2. Test and removal 3. Partial depopulation

19 Danish SPF system Established in 1968 by the Pig Industry THE BACK BONE of Danish Pig Production Total depop/repop program To-day 82% of all Danish pig herds Nearly 100% of nucelus & multiplying herds

20 The SPF diseases Herds declared free from infections Mycoplasma hyopneumoniae Actinobacillus pleuropneumoniae Toxigenic Pasteurella multocida Brachyspira hyodysenteriae Mange mite & lice PRRS Only approx. 21 % of the herds in 2017 have the highest health status Health status on the E-net = full transparency (

21 M.hyo free herds RED = nucleus & multiplying Blue = production

22 The DANISH SPF system Most new herds are stocked with SPF pigs! Increasing importance: Number of herds SPF herds 3500 (13 %) 3500 (60 %) 2648 (82%)

23 Biosecurity at the border Import of live animals Only very few live pigs (breeding animals) All in voluntary quarantine run by DAFC Export of live animals Trucks cleaned & disinfected at the border when returning Paid by the pig industry (DAFC)

24 High level of biosecurity Minimum distance to other farms Nucleus & multiplying herds 500 m Production herds 100 m Entry room (change of boots/clothes) Quarantine for persons (12 hours) Special compartment for pigs leaving the farm Empty and clean trucks for transportation

25 Entry

26 Personnel Access Always through official entry 12 hours down time Change clothes Change footwear Hand wash

27 SPF-Transport Special built trucks Well skilled truck drivers Inspection program of cleaning and disinfection 12 h down time from lower to higher status

28 SPF Company (trucks with Carbon Filter)

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30 Cleaning & desinfection

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32 Microbiological control

33 Control of health status in SPF herds Nucleus & multiplying herds Visit by VET every month Clinical signs Serological testing every month Production herds Visit by VET every three month Clinical signs Serological testing once a year

34 Supply of new genes 1. Semen (A.I.) 2. Replacement stock (gilts) 3. Gnotobiotic caesarean sections Only for nucelus herds sows per year Piglets moved to nursing sow in herd

35 The operation table at the clinic

36 A sleeping sow

37 The sterile operation room

38 The operation

39 An overview

40 The piglets

41 Plan for presentation Poul Baekbo and SEGES Danish pig production The Danish SPF system Elimination by Partiel Depopulation 1. PRRS 2. APP Conclusions

42 Partial depopulation Frequently used in Denmark in sow herds Alternative to total depop/repop (SPF) Reduced loss of production Genetics preserved Method Temporary changes in production flow Strategic medication Replacement stock from SPF herds

43 Partial depopulation in Denmark High succes rate Enzootic pneumonia (M.hyo) PRRS Dysentery (B.hyodys) Mange Medium high succes rate Pleuropneumonia (A.pp) Low or unknown succes rate Atrophic rhinitis Porcine proliferative enteropathy

44 PRRS in Denmark PRRS was first diagnosed in Denmark in 1992 The European type (type 1 = PRRS-DK) In 1996 a large national vaccination program With a MLV vaccine PRRS type 2 (PRRS VAC) was spread The aim of the program was to control and subsequently to eradicate PRRS from Denmark

45 PRRS in The Danish SPF-program 82% of the Danish herds are enrolled in the SPF program and have as such a PRRS declaration Of these SPF-herds, 72% are declared free from PRRS Out of the nucleus & multiplying herds, 98% are declared free from PRRS GOOD source for replacement stock

46 SPF herds: Blue lines = production herds, Red lines= nucleus & multiplying herds

47 Number of herds Number of herds where PRRS has been eliminated ( ) PRRS-DK PRRS-VAC now Year

48 Elimination of PRRS The Danish example Two ways of eliminating PRRS from herds in Denmark 1. The most common way (partial depop/repop) 1. By total depop/repop with a PRRS-negative stock Most new farms are started up with a PRRS negative stock

49 Partial depopulation for PRRS Central conditions for succes 1. The infection must have stabilised in the sow unit (no shedding of virus) No infected weaners Blood testing of 8-10 weeks weaners 3 times with one month interval (all seronegative in IPMA test) 2. Weaning in AI/AO units 3. No growers & finishers

50 Partial depopulation for PRRS Before During After Immune replacement stock Weaning in units with AIAO One way flow of pigs Culling of growers & finishers (Farrowing stop for 2-3 weeks) Non-infected replacement stock

51 Main challeges against PRRS elimination 1. Dense pig population in many areas (re-infections!) 2. No systematic testing of all farms 3. Boar studs are infected 4. Not of interest for the national animal health authorities 5. No economic cost-benefit analyses (ROI: do it pay off?)

52 National PRRS eradication? TWO additional challenges 1. How to motivate the farmers A volontary program at start of the program 2. How to ensure national freedom, once obtained

53 National loss due to PRRS in Denmark (2013) Mio. Euro/year Abattoir related cost Loss health value export breeding gilts Loss export value piglets Loss Chronic PRRS Loss acute PRRS 43,62 3,22 0,42 13, ,36 15,03 2,32 0,34 4,34 24,02 1,34 0,25 2,17 6,44 1,93 0,67 1,59 2,95 Low Medium High

54 National loss due to PRRS in Denmark (2013) Mio. Euro/year Abattoir related cost Loss health value export breeding gilts Loss export value piglets Loss Chronic PRRS Loss acute PRRS 43,62 3,22 0,42 13, ,36 15,03 2,32 0,34 4,34 24,02 1,34 0,25 2,17 6,44 1,93 0,67 1,59 2,95 Low Medium High

55 Costs of a national Danish eradication program (1) 5 year program First year Year 2-4 Year 5 test of all herds + planning Eradication (partial & total depop/repop) Documentation for PRRSV freedom Estimated costs 120 mill. Euro mill. Euro Planning + tests of farms + administation mill. Euro Eradicaton costs + loss of production

56 Costs of a national Danish eradication program (2) Estimated loss due to PRRS Estimated costs of eradication 15 mill. Euro 120 mill. Euro Pay-back time: 15 years! NO national program

57 Plan for presentation Poul Baekbo and SEGES Danish pig production The Danish SPF system Elimination by Partiel Depopulation 1. PRRS 2. APP Conclusions

58 PLEUROPNEUMONIA

59 Actinobacillus pleuropneumoniae (App) 18 different serotypes Variation in virulence Some immunological cross protection Many herds infected Servere pleuropneumonia Can cause high mortality

60 Partial depopulation for App Most results published as case reports Different procedures Few farms Not all failures reported? Apparent succes rate might be too high?

61 Partial depopulation for App In general a low succes rate less than 50%!!! Why? App in the tonsils App in the environment With one possible exception Flouroquinolone injections seem superior (P. Wallgren et al, 1999)

62 Partial depopulation for App a clinical trial (1) 9 chronically infected herds Neighbour farms more that 500 m away Breeding animals vaccinated (twice) Culling of weaners, growers, finishers Stop for farrowing for 4 weeks Medication of sows (> 10 month old) in piglet free period Day 1: Injection of BAYTRIL (5 mg/kg ) Day 4: Injection of BAYTRIL (5 mg/kg )

63 Page 63 The eradication procedure Time line in 9 chronically infected herds App vaccination finalized on day -30 Stop for farrowings for 4 weeks Injection with Enrofloxacin day 0 & day 4 No introduction of replacemant stock for 3 month

64 Partial depopulation for App (2) No new replacement stock for 3 month Farms tested for APP freedom by serology (ELISA) and freedom of clinical signs (observation period: one year) Tested in 9 sow herds: Succes rate 75% (7 out of 9)

65 Conclusion SPF system Of big importance in Denmark A very well run system with high level of transparency Replacement stock for other elimination programmes Partial depopulation Safe & reliable method for elimination of PRRS & App (M.hyo, Dysentry & Mange)

66 Mycoplasma risk assessment by GIS Distance to nearest infected herd: 670 m Distance to nearest large infected herd: 1,200 m One-year mycoplasma survival probability: 91%