Controlling PRRS virus maximizes finishing performance Alex A.S. Eggen DVM Vietnam, 29 th October 2014

2 Content of Lecture Cost estimate of PRRS virus infection in the USA, 2 studies (2005 and 2011). General Oveview Cost estimate of PRRS virus infection in the Netherlands, 1 study (2007 – 2010). Specific farms Cost estimate individual case studies Factors influencing cost of PRRS infection Recommendations

3 USA; 2005 versus 2011 Data provided by Dr Derald Holtkamp Cost in 2005:$560 million Cost in 2011:$664 million  Increase partly due to inflation  Increase due to more effort for making breeding herds free of PRRS virus  But in any case no reduction in cost!

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5 PRRS free PRRS free, at least 12 mths PRRS+ve before outbreak PRRSv free before outbreak

6 PRRS +ve at weaning PRRS -ve at weaning and at market PRRS -ve at weaning but PRRSv +ve at market Less costs

7 Conclusions on USA PRRSv Costs Shift in costs to breeding herds –Consolidation, leading to larger farms –Increased willingness for breeding farms to spend $$ to prevent PRRSv infection (US$ per sow for depop/repop) –More emphasis on weaning PRRS-ve piglets PRRS still major cost factor for finishing units (55% of total cost!) –Poor performance leading to close-out problems –Increase in labor cost and use of Antimicrobials

8 Content of Lecture Cost estimate of PRRS virus infection in the USA, 2 studies (2005 and 2011) Cost estimate of PRRS virus infection in the Netherlands, 1 study Cost estimate individual case studies Factors influencing cost of PRRS infection Recommendations

9 Cost PRRS virus; Netherlands, Published in Veterinary Record March 2012 Breeding herds only, 9 in total (4 SPF, 5 Conventional) Followed for 18 weeks after infection Costs involved production data, medication, diagnostics, labour etc. Economic loss varied from €59 to €379 per sow for the 18 weeks post infection Cost after outbreak varied from €3 to €160 per sow due to different methods used by farmers

10 HERDGroup * Born Alive before outbreak Born Alive after outbreak Farrowing Index before outbreak Farrowing Index after outbreak 119,347,722,071, ,8010,601,992, ,809,302,202, ,1011,602,612, ,2211,832,462, ,5512,352,422, ,2012,102,322, ,9111,532,422, ,3810,712,282,02 Mean11,8110,862,312,26 * 1 PRRS-ve SPF herds, 2 PPRS +ve or unknown

11 HERDGroup * Pre weaning mortality % before outbreak Pre weaning mortality % after outbreak Post weaning mortality % before outbreak Post weaning mortality % after outbreak 1113,329,81,14,6 2113,016,61,03,1 3111,716,21,02,5 4119,923,6Piglets delivered/ sold to other farm at weaning 5213,515,60,71,5 6213,319,93,36,4 7215,418,40,62,7 8216,219,80,82,5 9211,513,41,32,4 Mean14,219,31,23,2 * 1: PRRS-ve, SPF herds 2: PPRS +ve or unknown, conventional herds

12 Conclusions Cost PRRSv infection Netherlands Large differences in costs after PRRSv infection between farms Differences in PRRS virus field strain and farm characteristics most likely reason for these differences Technical results back to normal after the 18 week period

13 Conclusions Cost PRRSv infection Netherlands (2) Only herd 4 and 9 vaccinated gilts and sows before the outbreak All herds vaccinated gilts and sows after the start of the outbreak. Herd 9 stopped vaccination after the period of the outbreak 4 herds started piglet vaccination Eradication in 1 herd by gilt/sow/piglet vaccination plus monitoring

14 Content of Lecture Cost estimate of PRRS virus infection in the USA, 2 studies (2005 and 2011) Cost estimate of PRRS virus infection in the Netherlands, 1 study Cost estimate individual case studies Factors influencing cost of PRRS infection Recommendations

15 Example 1 (Table 4) –1,200 sow farm –Goal: Produce 500 pigs/week –Successful prior to PRRSv –Post-PRRSv cost/pig increased to $9.00 Example 2 (Table 5) –2,400 sow farm –From open to closed –3 source changes, 3 PRRSv breaks –Closing herd, immediately improved bottom line USA: PRRS Control. The benchmark for closed herd success Kohler, AASV 2004, 199

16 Germany: PRRS +ve semen infecting SPF herds

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22 France: Cost/Benefit of Vaccination Study in France (Ridremont&Lebret, IPVS 2006) 6 Farrow-to-Finish farms (100 to 1,300 sows) classified as “unstable” based on 3-step program Porcilis® PRRS MLV Vaccination (Vx) protocol implemented –VaccinationD0, D28, booster every 4 months –D0 - D56: no entry of new gilts –After D56, entering gilts vx 2x at one month interval –Analysis: post vaccination at 3 months after D28

23 Farm 1Farm € 2007€ Pigs/Sow/Y , FC Post-Wean (369) (78) FC Post-Finish Slaughter (d) , ,092 % Mortality , ,476 Vet Cost/Sow/Y (€) , ,360 Cost of Vaccine18,0005,955 Primary Gain*79,63314,951 ROI (Ridremont&Lebret, IPVS 2008) * FC post wean & finish, age at slaughter, % mortality, veterinary cost/sow/y; Cost Benefit Vaccination France

24 Content of Lecture Cost estimate of PRRS virus infection in the USA, 2 studies (2005 and 2011) Cost estimate of PRRS virus infection in the Netherlands, 1 study Cost estimate individual case studies Factors influencing cost of PRRS infection Recommendations

25 Factors influencing cost of PRRSv infection Management  Batch mating, AIAO in farrowing, weaning, nursery and finishing unit  Only one directional flow of finihsing pigs, from farrowing unit to market  Only one directional flow of personnel  Preferably site and age segregation with dedicated personnel for the different sections  When breeding your own replacement gilts, special programs are required to adapt them to the breeding herd (housing, feeding, immune status, vaccination)  When purchasing replacement gilts, a farm specific gilt aclimatisation program is essential

26 Factors influencing cost of PRRSv infection Herd size  More difficult in large herds to obtain an equal level of immunity in all animals present  PRRS virus can hide in pockets on the farm and can spread from there to susceptible pigs causing new “breaks“. This is more likely to happen on large farms  PRRS virus field infection spreads slowly through a farm, small groups of animals may escape the field infection. This is more likely to happen on large farms  Biosecurity on large farms is more difficult to mantain. More laborers means more control necessary, pig flow often more compex. Sick animal pen is larger etc

27 Factors influencing cost of PRRSv infection Biosecurity  Never 100%. Examples import of PRRSv field virus by semen from “PRRS virus free” AI centres (Switserland, Germany)  Only works when easy to control protocols are continously communicated to staff. Drawings, different color booths, overalls for the different sections etc.  Good and functional operating biosecurity requires a high level of understanding of the importance of biosecurity in the whole organisation

28 Filtered Air Positive Pressure Houses

29 Factors influencing cost of PRRSv infection PRRS virus strain  ORF 5 of ORF 7 sequencing to show the presence of Type I and or Type II PRRS strains has no relevance for predicting pathogenicity  Both Type I and Type II PRRS field strains can cause significant economic damage  Type 1 vaccines do provide protection to Type II PRRS fieldstrains  Only in the 100% homologous situation the protection can be complete, in all other situation protection is partial  More severe when multiple pathogens are present

30 Economic impact is greater in combined infections. Swine Flu (SIV) different in the USA. PCV2 not considered Haden et al., AASV 2012, 74 Economic impact of PRRSv, SIV and Mhyo alone and in combination

31 HP-PRRS challenge in pigs vaccinated with Porcilis Prrs In 2006, Porcine High Fever Disease in growing pigs emerged from China –High fever, anorexia, listless, respiratory problems –High morbidity and mortality –Many pathogens were isolated from affected cases Confirmation that HP PRRS only was involved was discovered when studies with JX143 PRRSv (HP PRRS) were done by Kelly Lager et al., National Animal Disease Center, Ames, IA, USA 31

32 Porcilis PRRS/ HP PRRS virus Vaccination/ Challenge Study Design 32 3 Groups 1.Challenge control n=15 pigs 2.Porcilis PRRS Vaccinated pigs n=15 3.Control n=14 4 wk old pigs, negative for PRRS Pigs were housed by treatment Objective: To evaluate efficacy of Porcilis PRRS in pigs vaccinated at 4 weeks of age and challenged with HP-PRRSv (rJXwn06, 65% homology) at 8 weeks of age.

33 Results Pigs vaccinated with Porcilis PRRS had higher weight gains, reduced viremia and less mortality than challenge controls following a severe experimental challenge with HP- PRRS. Viremia

34 EFFICACY OF PORCILIS ® PRRS AGAINST A NA TYPE PRRSV CHALLENGE IN PIGLETS ORF5 homology of Challenge strain Type II Strain B was isolated in Kagoshima, Japan. Strain isolated from the lung of piglets. Pneumonia and petechia of kidney were indicative of PRRSV.

35 Results ~ Clinical observation ~ Vaccinated pigs showed mild signs of lethargy and dyspnea (only 2 pigs & 3 days) from 6 dpc.

36 Results ~ Clinical observation 2 ~ d7 ; Contd17 ; Cont d7 ; Vac d17 ; Vac

37 Results ~ Body weight ~ After the NA type challenge, the BW (kg) of all animals in the vaccinated group was heavier than the control.

38 Conclusion vaccination challenge experiments These studies demonstrate that I.M. vaccination with Porcilis is effective against NA type challenge 4 weeks after vaccination The challenge strains in these studies were highly pathogenic for (young-) piglets. As a result, the difference of efficacy between vaccinated and control pigs is very clear

39 Controlling PRRS for maximising performance Herd size, Management, Biosecurity, PRRS virus Vaccination programs in breeding herd is indicated : During outbreaks To uniform immune status of the herd To prevent infection of the young piglets with PRRS virus Vaccination programs in piglets is indicated : If infection occurs in the nursery, still an unstable breeding herd can be the origin of the infection and breeding stock vcaccination and piglet vaccination should be executed By infection in late nursery or start of growing phase, piglet vaccination is required to maximise performance

40 Recommendations After more than 25 years, PRRSv continues to have a negative impact on productivity and this results in a high financial cost for swine farms Multiple factors contribute to the severity of a PRRSv infection but the cost involved and the effect of control procedures are farm dependent Vaccination with mlv Porcilis PRRS vaccine to stimulate the immune system is the best option to limit economic damage