PEDv Survival: Feed Mitigation Strategies - Dr. Cassie Jones, from the 2015 Allen D. Leman Swine Conference, September 19-22, 2015, St. Paul, Minnesota, USA. More presentations at http://www.swinecast.com/2015-leman-swine-conference-material

1. Survival of PEDV in Feed,
Feed Ingredients, and Interventions:
Feed Mitigation Strategies
Dr. Cassie Jones
Allen D. Leman Swine Conference

2. Prevention of Biological Hazards in Feed
• Why is PEDV mitigation important?
• Food Safety Modernization Act
– Most feed mills will need to establish Animal Food
Safety Plans to identify and control hazards
• Agents that have the potential to cause illness or injury or
in humans or animals
• Include microbiological pathogens, such as viruses
Swine Health Monitoring Project, 2015

3. Prevention of Biological Hazards in Feed
• Why is PEDV mitigation important?
– Our charge in feed manufacturing:
Control animal food safety hazards to fulfill our role
in preserving farm-to-fork food safety.

4. Prevention of Biological Hazards in Feed
• Prevention
– Exclusion (biosecurity)
• Ingredients
• People
• Transportation
• Proactive mitigation
– Point-in-time
• Thermal
• Irradiation (UV, UVC, ionizing)
• Dilution
– Residual
• Chemicals
– Acids and alkalis
– Formaldehyde
– Medium chain fatty acids
– Essential oils
Depending on your
risk and aversion to it,
multiple strategies
may be combined

5. Prevention of Biological Hazards in Feed
• Prevention
– Exclusion (biosecurity)
• Ingredients
• People
• Transportation
– Resources
• Feed Mill Biosecurity session tomorrow morning (Room 8)
– Jason Woodworth
– Laura Greiner
– Tim Snider
• AFIA’s “Developing Biosecurity Practices for Feed &
Ingredient Manufacturing”

6. Prevention of Biological Hazards in Feed
• Proactive mitigation
– Point-in-time
• Thermal
• Irradiation (UV, UVC, ionizing)
• Dilution
– Residual
• Chemicals
– Acids and alkalis
– Formaldehyde
– Medium chain fatty acids
– Essential oils

7. Cargill Feed Safety Research Center
• O.H. Kruse Feed Technology Innovation Center at
Kansas State University
– Cargill Feed Safety Research Center
• 3 story BSL-2 Lab
– Salmonella, E. Faecium, PEDV
– Pellet mills, coolers, and bagging capacities
– Containment mode
• Equipped with sanitation features
• Air flow alarms
• HEPA filters
• Decontamination

8. Point-in-Time Mitigation
• Thermal mitigation of PEDV by pelleting
– Exp. 1
• Low dose and high dose (20 and 13 Ct)
• 3 pellet mill conditioner retention times (45, 90, 180 s)
• 3 conditioning temperatures (155, 175, 195°F)

9. Point-in-Time Mitigation
• Thermal mitigation of PEDV by pelleting
– Exp. 1
Low Dose PCR Ct Values (20 Ct)
Time, sec
Temp, °F 45 90 180
155 43 40 45
175 37 40 42
195 40 37 36
Low Dose Feed No processing = 31
High Dose PCR Ct Values (13 Ct)
Time, sec
Temp, °F 45 90 180
155 30 30 30
175 30 30 30
195 30 31 30
High Dose Feed No processing = 24
No infectivity developed from any of the pelleted diets

10. Point-in-Time Mitigation
• Thermal mitigation of PEDV by pelleting
– Exp. 2
• Single dose (11 Ct)
• Single conditioner retention time (30 s)
• 5 conditioning temperatures (100, 115, 130, 145, and 160°F)
• Replicated manufacturing conditions
– 3 pigs/room – one from each manufacturing rep

11. Point-in-Time Mitigation
• Thermal mitigation of PEDV by pelleting
– Exp. 2 (3 replications)
PCR Ct Values
Time, sec
Temp, °F 30
100 32.5
115 34.7
130 37.0
145 36.5
160 36.7

12. Point-in-Time Mitigation
• Thermal mitigation of PEDV by pelleting
– Exp. 2 (3 replications)
Number of Pigs Infected with PEDV by Bioassay
Feed 0 dpi 2 dpi 4 dpi 6 dpi 7 dpi
7 dpi
Cecum
No PEDV 0 0 0 0 0 0 0
100°F 9/9 0 1/9 3/9 3/9 3/9 3/9
115°F 9/9 0 3/9 3/9 3/9 3/9 3/9
130°F 9/9 0 0 0 0 0 0
145°F 8/9 0 0 0 0 0 0
160°F 8/9 0 0 0 0 0 0
Infectivity developed in diets pelleted below 130°F

13. Point-in-Time Mitigation
• Thermal mitigation of PEDV by pelleting
– When is feed NOT conditioned to at least 130°F?
• Intentional extremely low conditioning temperatures (rare)
• Start-up
• Plugged dies
– Other potential mitigation strategies may be necessary
to consider IN ADDITION to pelleting

14. Point-in-Time Mitigation
• Irradiation of PEDV
–Dose-dependent
• 99.97% virus inactivation at 50 kGy
– 44 kGy recognized by NASA for sterilization of frozen
packaged meats
• 90% virus inactivation at 10 kGy
– 3 and 4.5 kGy recognized by FDA 21 CFR 179.26 for
pathogen control in eggs and refrigerated uncooked meat
products, respectively
–Potential for ingredients
–Not practical for large-scale feed production
Goyal et al.

15. Point-in-Time Mitigation
• Dilution of PEDV
– Sequencing or flushing are recognized cleanout
procedures for CGMPs of medicated feed
– One batch of PEDV-negative feed mixed, conveyed
through bucket elevator, discharged
– One batch of PEDV-positive feed followed
– Four subsequent sequences of PEDV-negative feed
followed
• Feed and environmental samples at multiple locations
collected after each batch

16. Point-in-Time Mitigation
• Dilution of PEDV
Number of Pigs Infected with PEDV by Bioassay
Time Point
Location
After
PEDV
Diet
After
Sequence
1
After
Sequence
2
After
Sequence
3
After
Sequence
4
2 dpi (fecal) 9/9 1/9 1/9 ? ?
7 dpi (cecum) 9/9 3/9 3/9 ? ?
Number of Feed Samples When PEDV was Detected by PCR
Time Point
Location
After
PEDV
Diet
After
Sequence
1
After
Sequence
2
After
Sequence
3
After
Sequence
4
Mixer 9/9 7/9 0 0 0
Bucket Elevator 9/9 7/9 2/9 0 0

17. Point-in-Time Mitigation
• Dilution of PEDV
– Why is infectious RNA still present in the next batch?
0.0
20.0
40.0
60.0
80.0
100.0
PositiveCtforPEDV,%

18. Problem with Point-in-Time Mitigation
• Does not eliminate potential for cross-
contamination
–Within mill: Conveyors, coolers, bins, load-out
–Transportation: Trucks, unloading
–Within farm: Bins, feed lines, feeders

19. Residual Mitigation
• Proactive mitigation
– Point-in-time
• Thermal
• Irradiation (UV, UVC, ionizing)
• Dilution
– Residual
• Chemicals
– Acids and alkalis (Goyal et al.)
– Formaldehyde (Dee et al.)
– Medium chain fatty acids
– Essential oils

20. Residual Mitigation
• Chemical treatments
1. Untreated control
2. Commercial formaldehyde (Termin-8)
3. Essential oil mixture (garlic, turmeric, capsicum, oregano, and
rosemary, 1:1 blend, 2% wt/wt)
4. Medium chain fatty acid mixture (caproic acid, caprylic acid, and capric
acid, 1:1 blend, 2% wt/wt)
5. Organic acid mixture (lactic acid, propionic acid, formic acid, benzoic
acid, 1:1 blend, 3% wt/wt)
6. Sodium bisulfate (1%)
7. Sodium chlorate (1%)
• Four feed matrices: swine diet, avian blood meal,
porcine meat and bone meal, and spray dried porcine
plasma

21. PEDv contamination post-treatment in
swine diets stored at room temperature
26
28
30
32
34
36
38
40
0 10 20 30 40
QuantitativeCTValues
Day
Untreated control Medium chain fatty acid Essential oil
Organic acid Sodium bisulfate Sodium chlorate
Commercial formaldehyde
Ingredient × day, P < 0.0001
Treatment × day, P < 0.0001
Ingredient × treatment, P < 0.0001

22. PEDv contamination post-treatment in
avian blood meal stored at room temperature
24
26
28
30
32
34
36
38
40
0 10 20 30 40
QuantitativeCTValues
Day
Untreated control Medium chain fatty acid Essential oil
Organic acid Sodium bisulfate Sodium chlorate
Commercial formaldehyde
Ingredient × day, P < 0.0001
Treatment × day, P < 0.0001
Ingredient × treatment, P < 0.0001

23. PEDv contamination post-treatment in
porcine meat and bone meal stored at room temperature
24
26
28
30
32
34
36
38
40
0 10 20 30 40
QuantitativeCTValues
Day
Untreated control Medium chain fatty acid Essential oil
Organic acid Sodium bisulfate Sodium chlorate
Commercial formaldehyde
Ingredient × day, P < 0.0001
Treatment × day, P < 0.0001
Ingredient × treatment, P < 0.0001

24. PEDv contamination post-treatment in
spray dried porcine plasma stored at room temperature
26
28
30
32
34
36
38
40
0 10 20 30 40
QuantitativeCTValues
Day
Untreated control Medium chain fatty acid Essential oil
Organic acid Sodium bisulfate Sodium chlorate
Commericial formaldehyde
Ingredient × day, P < 0.0001
Treatment × day, P < 0.0001
Ingredient × treatment, P < 0.0001

25. Untreated controls stored at room temperature
24
26
28
30
32
34
36
38
40
0 10 20 30 40
QuantitativeCTValues
Day
Swine diet Blood meal Porcine meat and bone meal Spray dried animal plasma

26. • Time, formaldehyde, medium chain fatty acid, and essential
oil treatment all enhance the degradation of PEDV RNA in
feed ingredients
– Varies within the feed matrix
– Not necessarily indicative of infectivity
• Stability of PEDV varies over time depending upon matrix
• Ongoing:
– Evaluation of appropriate concentrations, combinations,
and effectiveness of MCFA by bioassay
– Evaluation of MCFA in various ingredients by VI, bioassay
– Evaluation of various dry and wet applications for
surface decontamination
Residual Mitigation

27. • Diets pelleted with a 30 s conditioning time above 130°F
were non-infectious.
– Considerations required for plugs, start-up of pellet mills
• Irradiation may be effective, but is only practical for
ingredients
• Sequencing diets dilutes PEDV, but infectivity remains
– Particularly on equipment surfaces
• Formaldehyde, MCFA, essential oils demonstrate some
ability to reduce PEDV RNA, but is ingredient dependent
– Effectiveness against infectivity must be validated and feasible
concentrations determined
• Multiple preventive and proactive strategies may need to be
employed to maximize PEDV control
Take Home Messages

28. Partners in PEDV Research
• K-State Applied Swine Nutrition Team
– Drs. Schumacher, Dritz, Woodworth, Tokach, DeRouchey,
and Goodband; Jordan Gebhardt
• K-State Grain Science
– Drs. Jones, Stark, and Huss; Roger Cochrane
• K-State VDL
– Drs. Hesse, Bai, Haus, Anderson, and their team
• Iowa State University VDL
– Drs. Main, Zhang, Gauger, and their team
• National Pork Board, USDA