Survival of PEDV in Feed, Feed Ingredients, and Interventions:

Feed Mitigation Strategies

Dr. Cassie JonesAllen D. Leman Swine Conference

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

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.

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

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”

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

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

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)

Point-in-Time Mitigation• Thermal mitigation of PEDV by pelleting– Exp. 1

Low Dose PCR Ct Values (20 Ct) Time, secTemp, °F 45 90 180

155 43 40 45175 37 40 42195 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 30175 30 30 30195 30 31 30

High Dose Feed No processing = 24

No infectivity developed from any of the pelleted diets

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

Point-in-Time Mitigation• Thermal mitigation of PEDV by pelleting– Exp. 2 (3 replications)

PCR Ct Values Time, secTemp, °F 30

100 32.5115 34.7130 37.0145 36.5160 36.7

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 dpi7 dpi

CecumNo PEDV 0 0 0 0 0 0 0100°F 9/9 0 1/9 3/9 3/9 3/9 3/9115°F 9/9 0 3/9 3/9 3/9 3/9 3/9130°F 9/9 0 0 0 0 0 0145°F 8/9 0 0 0 0 0 0160°F 8/9 0 0 0 0 0 0

Infectivity developed in diets pelleted below 130°F

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

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.

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

Point-in-Time Mitigation• Dilution of PEDV

Number of Pigs Infected with PEDV by Bioassay Time Point

Location

AfterPEDVDiet

After Sequence

1

After Sequence

2

After Sequence

3

After Sequence

42 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

AfterPEDVDiet

After Sequence

1

After Sequence

2

After Sequence

3

After Sequence

4Mixer 9/9 7/9 0 0 0

Bucket Elevator 9/9 7/9 2/9 0 0

Point-in-Time Mitigation• Dilution of PEDV – Why is infectious RNA still present in the next batch?

Baselin

e

After Neg.

Diet

After PEDV Diet

After Flush

1 Diet

After Flush

2 Diet

After Flush

3 Diet

After Flush

4 Diet

After Syn

ergize

After Bleach

After 48 h Hea

t0.0

20.0

40.0

60.0

80.0

100.0

Positi

ve C

t for

PED

V, %

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

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

Residual Mitigation• Chemical treatments

1. Untreated control2. 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

PEDv contamination post-treatment in swine diets stored at room temperature

0 5 10 15 20 25 30 35 40 452628303234363840

Untreated control Medium chain fatty acid Essential oilOrganic acid Sodium bisulfate Sodium chlorateCommercial formaldehyde

Day

Qua

ntita

tive

CT V

alue

s

Ingredient × day, P < 0.0001Treatment × day, P < 0.0001Ingredient × treatment, P < 0.0001

PEDv contamination post-treatment in avian blood meal stored at room temperature

0 10 20 30 40242628303234363840

Untreated control Medium chain fatty acid Essential oil Organic acidSodium bisulfate Sodium chlorate Commercial formaldehyde

Day

Qua

ntita

tive

CT V

alue

s

Ingredient × day, P < 0.0001Treatment × day, P < 0.0001Ingredient × treatment, P < 0.0001

PEDv contamination post-treatment in porcine meat and bone meal stored at room temperature

0 10 20 30 40242628303234363840

Untreated control Medium chain fatty acid Essential oilOrganic acid Sodium bisulfate Sodium chlorateCommercial formaldehyde

Day

Qua

ntita

tive

CT V

alue

s

Ingredient × day, P < 0.0001Treatment × day, P < 0.0001Ingredient × treatment, P < 0.0001

PEDv contamination post-treatment in spray dried porcine plasma stored at room temperature

0 10 20 30 4026

28

30

32

34

36

38

40

Untreated control Medium chain fatty acid Essential oil Organic acidSodium bisulfate Sodium chlorate Commericial formaldehyde

Day

Qua

ntita

tive

CT V

alue

s

Ingredient × day, P < 0.0001Treatment × day, P < 0.0001Ingredient × treatment, P < 0.0001

Untreated controls stored at room temperature

0 10 20 30 40242628303234363840

Swine diet Blood meal Porcine meat and bone meal Spray dried animal plasma

Day

Qua

ntita

tive

CT V

alue

s

• 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

• 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

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