Dietary phytonutrients enhance disease resistance of pigs

Yanhong Liu,*,1 D. Bravo,2 and J. E. Pettigrew3

University of California, Davis, USA1, Pancosma SA, Geneva, Switzerland2, and University of Illinois, Urbana, USA3

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2nd International Symposium - Alternatives to Antibiotics, 2016

Outline

• Previous knowledge

• Hypothesis

• Test of hypothesis

• What does it mean?

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Weaning stress

• Maternal separation

• Environmental change

• Increased exposure to pathogens

• Social hierarchy stress

• Move to solid feed

• Transportation stress

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Gut morphology change of weanling pigs

• Reduced feed intake

• Negative effects on intestinal morphology

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Declined intestinal functions

• Reduced brush-border enzyme activity

• Reduced absorption ability

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• Diarrhea

• Poor growth performance

Immunity of weanling pigs• Passive immunity is declining• Active immunity is not fully developed

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• Highly sensitive to infectious disease

• Divert nutrients away from growth to immune response

• Poor growth performance

Antibiotic use on farms

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1

2

3

Van Boeckel et al., 2015 PNAS

Feed additives

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• Mannan oligosaccharides

• Immune egg products

• Direct-fed bacteria

• Yeast/yeast products

• Plant extracts

Plant extracts

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• Extracted from parts of plants or synthesized

• Concentrated, hydrophobic, volatile aroma

• Mixtures of secondary plant metabolites

• Liquid or powder

• Phenolic compounds

Plant extracts

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• Biological effects:

Antimicrobial Anti-inflammatoryAntioxidantOthers: Antiviral, Antifungal, Antiparasitic,

Antitoxigenic

Hypothesis

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1) Certain plant extracts modify immune function of pigs

2) This leads to increased disease resistance

Test of hypothesis

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• Exp. 1: In vitro cell culture

• Exp. 2: E. coli challenge study

• Exp. 3: PRRS challenge study

Experiment 1

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In vitro cell culture assays

Anti-inflammatory effects

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Liu et al., 2012

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* * *0

10

20

30

40

50

ng/m

L

02550100200

TNF-α *P < 0.05

LPS-stimulated porcine alveolar macrophages

Anti-inflammatory effects

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Liu et al., 2012

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10

12

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ng/m

L

02550100200

IL-1β *P < 0.05

LPS-stimulated porcine alveolar macrophages

Conclusions – Exp. 1

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• All of plant extracts used in this experiment may have potent anti-inflammatory effects

• Carvacrol, cinnamaldehyde, eugenol, and garlicon might be the more powerful candidates

• Capsicum oleoresin, garlicon, and turmeric oleoresin were selected to do E. coli and PRRSV challenge studies

In vivo E. coli challenge study

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Liu et al., 2013a

Experiment 2

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Liu et al., 2013a

Procedures

d-4

d0

d3

Weaning (21 d old)

Daily diarrheaFecal culture

F18 E. coli inoculation (d0 to d2)

Room

ChamberWhite blood cell countsCytokinesAcute phase proteins

Sows screening

ImmunohistochemistryIntestinal morphologyqPCR & Microarray (d 5)

* 4 diets: control, 10 ppm capsicum oleoresin, 10 ppm garlicon, 10 ppm turmeric oleoresin

*

d5

d8

d11

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05

1015202530354045

d0-11 PI d0-11 PI

Sham E. coli

ControlCapsicumGarliconTurmeric

%

Control vs. plant extractsP < 0.05

Liu et al., 2013a

Control vs. plant extractsP < 0.05

Pig days with diarrhea score ≥ 31, normal; 5, watery diarrhea

Frequency of diarrhea

Liu et al., 2013a, 2014

Possible mechanism for reduced diarrhea

* * *

050

100150200250300350400450

Sham E. coli

μm

* *

0

30

60

90

120

150

180

E. coli

ControlCapsicumGarliconTurmeric

Possibly improved gut barrier function!

Ileal villi height (d 5 PI) MUC2 in Ileal mucosa (d 5 PI)

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020406080100

Control Capsicum Garlicon Turmeric

Plant extracts reduced systemic inflammation caused by E. coli infection

Liu et al., 2013a

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* *

0

5

10

15

20

25

30

35

40

d5 PI d11 PI

×10

00/μ

L

White blood cell counts

* ** *

0

20

40

60

80

100

120

d5 PI d11 PI

pg/m

L

Serum TNF-α

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*** *

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0

500

1000

1500

2000

2500

Macrophage Neutrophil

Control CapsicumGarlicon Turmeric

Plant extracts reduced gut inflammation caused by E. coli infection

Liu et al., 2013a

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Ileal mucosa, d 5 PI

ShamMacrophage

E. coliMacrophage

Ileum (d 5 PI)

Plant extracts reduced gut inflammation caused by E. coli infection

Liu et al., 2014

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*** *

*

*

0

50

100

150

200

250

COX-2 TNFA

Control CapsicumGarlicon Turmeric

The Prostaglandin Pathway

Arachidonic acid

PGG2

PGH2

TXA2

PGF2αPGE2

PGD2PGI2

Inflammation!

E. coli challenge group

Cyclooxygenase-2 (COX-2)

TNF-α

Conclusions – Exp. 2

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• Feeding plant extracts reduced diarrhea and enhanced disease resistance of weanling pigs

• Possible mechanisms• Gut barrier function• Gut mucosa immunity • Systemic immunity

In vivo porcine reproductive and respiratory syndrome virus (PRRSV)

challenge study

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Liu et al., 2013b

Experiment 3

Rectal temperature

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Liu et al., 2013b

39.0

39.5

40.0

40.5

41.0

d 0 d 4 d 7 d 9 d 11 d 14

˚C

CONCAPGARTURCON+PRRSVCAP +PRRSVGAR+PRRSVTUR+PRRSV

d 7, 9, 11: PRRSV: P < 0.01

* CAP vs. CON: P < 0.05# GAR vs. CON: P < 0.05

* #

Feed efficiency, d 0-14

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Liu et al., 2013b

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0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Sham PRRSV

ADG

:AD

FI

ControlCapsicumGarlicTurmeric

PRRSV: P = 0.07

* *

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10

13

16

19

22

25

28

31

d 7 d 14

Ct v

alue Control

CapsicumGarlicTurmeric

Serum viral load-PRRSV

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Liu et al., 2013b

CON vs. PE: P < 0.05

d 7 & 14: PRRSV: P < 0.01

CON vs. PE: P = 0.05

Serum TNF-α - PRRSV

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Liu et al., 2013b

* *

0

50

100

150

200

250

d 7 d 14

pg/m

L ControlCapsicumGarlicTurmeric

CON vs. PE: P < 0.05

d 7 & 14: PRRSV: P < 0.01

*

0

10

20

30

40

50

60

d 7 d 14

µg/m

L ControlCapsicumGarlicTurmeric

Serum C-reactive protein- PRRSV

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Liu et al., 2013bd 7 & 14: PRRSV: P < 0.01

CON vs. PE: P < 0.05

Conclusions – Exp. 3

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• Feeding plant extracts delayed fever caused by PRRS infection

• Feeding plant extracts improved feed efficiency of pigs

• Possible mechanisms• Reduced viral load• Reduced systemic inflammation

Hypothesis

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1) Certain plant extracts modify immune function of pigs Accept

2) This leads to increased disease resistance Accept

Acknowledgements

• Dr. Pettigrew lab – University of Illinois

• Pancosma

UCDAVIS

2nd International Symposium - Alternatives to Antibiotics, 2016

UCDAVIS

2nd International Symposium - Alternatives to Antibiotics, 2016

Comparative Animal Nutrition & Physiology Laboratory

http://animalnutr-ansci.faculty.ucdavis.edu/