Antimicrobials used in layers: the Belgian situation Dr Erik Uyttebroek Dr Dieter Vancraeynest II. National Egg Summit, Antalya, 5-8 November 2015

Overview The regulatory environment Antimicrobials available for use in layers in Belgium (0d egg WDL) Main indications for antimicrobial use in layers Use of antimicrobials and possible non-antimicrobial alternatives per indication Conclusion

The regulatory environment Pressure on antimicrobial use MRSA, ESBL  political and retailer demands to reduce the usage of antimicrobial agents Eg. the Netherlands: 20% reduction in 2011 50% reduction in 2012! (aim was 2013) Belgium: 50 % reduction by 2020 50 % reduction in feed medication by 2017 Stricter guidelines on what to use when Products reserved for 2nd and 3rd line treatment

The regulatory environment But: most pressure is on meat production Egg production already had limited use of antimicrobial agents Not much agents available with 0d WDL

Antimicrobials available for use in layers in Belgium (0d egg WDL) Colistine Tylosin Tiamulin Phenoxymethylpenicillin

Main indications for antimicrobial use in layers Escherichia coli Necrotic enteritis Chronic enteritis/focal duodenal enteritis Mycoplasma synoviae Erysipelothrix rhusiopathiae Pasteurella multocida AIS (Avian Intestinal Spirochetosis - Brachyspira)

Escherichia coli Current situation: 2 main ports of entry: Still one of the most important reasons for mortality during lay, but currently not to the same extent as in the past 2 main ports of entry: Aerogenic  respiratory issues, aerosacculitis, pericarditis, (pneumonia) Ascending from cloaca  oophoritis, peritonitis

Escherichia coli - Antimicrobial approach: Colistine but no resorption from GI tract 60,000-80,000 IU/kg/day 3-5d Multi Resistance

Escherichia coli - Non-antimicrobial approach: Vaccination: Autovaccines More recently: commercial live vaccine (Poulvac E. coli), sometimes in combination with autovaccines In cases of APEC (on the rise): water treatment Pulse washing, peracetic acid, …

Escherichia coli - Vaccination Commercial live vaccine (Poulvac E. Coli) Live aroA deleted E. coli O78 Broad cross protection (studies for O1, O2, O18) Spray administration from day 1 onwards, until 6w before onset of laying Usually 2 vaccinations during rearing period High adoption after introduction in long living birds (layers and breeders) Emergency vaccination seems beneficial

Escherichia coli Commercial Live Vaccine: adoption rate* 2014: Country *Estimated % of layers/breeders vaccinated in EU per country assuming every layer and breeder received 2 doses Country # layers in mio # breeders Adoption rate* 2014 Hungary 7,3 0,5 55% France 44,0 6,0 46% United Kingdom 34,0 7,0 40% Bulgaria 3,0 0,4 37% Portugal 29% Ireland 2,0 0,6 27% Belgium/Luxemb. 24% Germany 38,0 15,0 23%

Necrotic enteritis Current situation: Unpredictable immunity Cooper and Songer Current situation: Regular clinical outbreaks during rearing or early lay Mostly preceded by or combined with coccidiosis Coccidiosis prevention often absent during rear Unpredictable immunity  Coccidiosis pops up after stressors (transport, peak of lay)  Followed by NE

Necrotic enteritis Antimicrobial approach Non-antimicrobial approach Phenoxymethylpenicillin (recent 0d egg WDL) 20 mg/kg/day for 2d, then 13.5 mg/kg/day for 3d Distribution of daily dose in 6-8 hours Tylosin 20 mg/kg for 3d Non-antimicrobial approach Make sure birds enter production with good cocci immunity

Chronic enteritis/focal duodenal enteritis Current situation Regularly seen in commercial layers in alternative housing systems

Chronic enteritis/focal duodenal enteritis Antimicrobial approach Tylosin Non-antimicrobial approach NSAIDs Methyl-salicylic acid in feed Copper sulphate in water Feed adaptations (more fiber, alfalfa, focus on protein digestibility) Acids in feed or water (formic, acetic, propionic acid)

Mycoplasma synoviae EAA: eggshell apex abnormalities Source: the Poultry Site

Mycoplasma synoviae Current situation Approx 30% of flocks show problems with egg shell quality after 40-45 weeks of age

Mycoplasma synoviae Antimicrobial approach Tylosin Tiamulin 75-100 mg/kg for 3-5d Tiamulin 25 mg/kg, 3-5d

Mycoplasma synoviae Non-antimicrobial approach Vaccination: commercial live M. synoviae vaccine (MS-H vaccine) On problem farms On farms producing table eggs, to reduce 2nd choice and breaking eggs on stacked trays In severe cases: moulting seems to stop problems

Erysipelothrix rhusiopathiae Current situation Frequent diagnosis in free range layers Often associated with swine production in proximity Antimicrobial approach Phenoxymethylpenicillin (although no claim) Non-antimicrobial approach Autovaccines Emergency vaccination also helps Reduce red mites! Collect mortality as often as possible! Work on cannibalism

Pasteurella multocida Current situation Sporadic problems Antimicrobial approach: In practice: almost impossible with 0d WDL products (Colistine) Non-antimicrobial approach Autovaccines and/or commercial vaccine

Brachyspira (AIS) Mostly described in free range layers Foamy yellowish caecal droppings Impact on egg production Source: Octagon services

Brachyspira Current situation Antimicrobial approach Not the major issue in Belgium Antimicrobial approach Tylosin Tiamulin No Brachyspira claim, only Mycoplasma 25 mg/kg, 3-5d

Conclusion Not a lot of antimicrobial agents with 0d egg WDL Need for reduction of antimicrobial use Need for alternative approaches Management Non-antimicrobial products New vaccines

Thank you for your attention! erik.uyttebroek@zoetis.com