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

2. 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

3. 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

4. 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

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

6. 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)

7. 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

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

9. 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, …

10. 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

11. 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%

12. 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

13. 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

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

15. 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)

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

17. Mycoplasma synoviae Current situation
Approx 30% of flocks show problems with egg shell quality after weeks of age

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

19. 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

20. 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

21. 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

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

23. 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

24. 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

25. Thank you for your attention!