Influence of Wean Age and Disease Challenge on Progeny Life-time Performance

D. S. Rosero*, T. Donovan and R. D. Boyd

The HanorCompany, Franklin, KY USA

WEANING: myriad of stressors for the young pig!

abrupt maternal separationso

cial

hie

rarc

hytr

ansp

orta

tion

hand

ling

different food source

co-mingling different litters

physical environment pathogens

antig

ens

WEANING: Disruption of GI structure and function

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200

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800

1000

1200

1400

-1 0 1 2 3 4 5 6 7 8 9 10 11 12

Villo

us h

eigh

t, µm

Days after weaning

Unweaned

Weaned

Hampson, 1986; Res Vet Sci 40:32-40; Lindemann et al., 1986; J Anim Sci 62:1298-1307

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-8 -6 -4 -2 0 2 4 6 8 10 12 14 16

Enzy

me

activ

ity (X

1000

0)

Days after weaning

Unweaned Unweaned

Weaned Weaned

Amylase

Reduced digestive enzyme activityVilli atrophyLipase

(hypothetical)

PARADIGM: Early-life Stress and GI disease development

Early weaning

Plasticity

Stre

ss se

nsiti

vity

Dise

ase

Risk

and

Sev

erity

Pohl, Medland, and Moeser 2015; Am J Physiol-GI 309:G927-G941

Life-time

Barrier function is compromised

EARLY-WEANING STRESS: disruption of intestinal barrierUssing Chamber Technique

3H-Mannitol14C-Inulin Supernatant

↑ Flux = ↓ barrier function

a

b

b

c

c

0

0.1

0.2

0.3

0.4

0.5

0.6

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0.9

15 18 21 23 28

3H-M

anni

tol f

lux,

µm

ol-c

m2

h

Weaning Age

Smith et al., 2010; Am J Physiol GI 298: G352–G363

EARLY-WEANING STRESS: long-lasting impact on barrier functionUssing Chamber Technique

3H-Mannitol14C-Inulin Supernatant

↑ Flux = ↓ barrier function

Smith et al., 2010; Am J Physiol GI 298: G352–G363

*

*

* *

0

1

2

3

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6

0 20 40 60 80 100 120 140 160 180

3H-M

anni

tol f

lux,

µm

ol-c

m2

h (x

10-3

)

Days after weaning

Early weaning

Late weaning

EARLY-WEANING STRESS: Subsequent stressors

Impact of Wean Age on intestinal barrier function and immune response to E. coli challenge

McLamb et al., 2013; PloS ONE, 8:e59838

b

b

c

aa

bc

0

1

2

3

4

5

6

7

8

9

10

16 18 20

Muc

osal

-to-

Sero

sal f

lux,

µg

FD4/

min

Weaning Age

Control

ETEC Challenge

c c

bc

c

b

a

0

5

10

15

20

25

30

35

16 18 20

Neu

trop

hils/

HPF

Weaning Age

Intestinal Permeability Immune response

EARLY-WEANING: myriad of stressors with long-lasting impact

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10

20

30

40

50

60

0 10 20 30 40 50 60 70

BW, l

bs

Age, d

Late weaned

Early weaned

Weaning

Early weaning negatively impact:

• Intestinal structure • Brush border enzyme activity• Intestinal barrier function• Immune response

Impact is exacerbated by other stressors:

• Management – mixing and crowding• Infectious challenges

…. and many more!

Response is immediate, acute and long-lasting

Impact of weaning age on performance of pigs

500

550

600

650

700

750

12 15 18 21 15.5 18.5 21.5

ADG

(wea

ning

to d

153

-156

), g

Weaning Age

Linear, P < 0.001

Linear, P < 0.001

0

2

4

6

8

10

12

12 15 18 21 15.5 18.5 21.5

Wea

n-Fi

nish

Mor

talit

y, %

Weaning Age

Linear, P < 0.001

Linear, P = 0.03

Main et al., 2004; J Anim Sci 82:1499-1507

Growth rate Mortalityn = 1,920 & 3,000 pigs

Trial 1 Trial 2 Trial 1 Trial 2

n = 1,920 & 3,000 pigs

PURPOSE To investigate and quantify the impact of weaning age on pig performance within a

multisite production system

• Impact of weaning age during health challenge events

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1/1/2010 7/20/2010 2/5/2011 8/24/2011 3/11/2012 9/27/2012 4/15/2013 11/1/2013 5/20/2014 12/6/2014

Aver

age

Wea

ning

Age

per

wee

k

Wean Date

Active PRRS Active PEDV

Weaning Age of Groups of Pigs by Weaning Date

METHODS

Sow Farm: DN Sow Farm (2,800 sows) located in North Carolina

Pig groups: 143 wean-to-finish groups (1,932 ± 793 pigs per group) located in Iowa

Weaning dates: Jan 2010 to Dec 2014

Weaning age:

0

5

10

15

20

25

30

35

17 18 19 20 21 22 23 24 25 26

Gro

ups o

f pig

s, n

Weaning Age

METHODS (Cont.)

Calculations:

• Growth performance data (ADG, ADFI, FCR)

were standardized to a final weight of 136 kg

Production records:

• Sow farm: weekly wean age distribution, monthly performance

• Close-outs: placement and end dates, start and end weights, feed per head, mortality, off-grade pigs

Health Status records:

• PRRS, Jan to March of 2010

• PEDV, Jan and Feb of 2014

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20

40

60

80

100

120

140

0 50 100 150 200 250

Fina

l bod

y w

eigh

t, kg

Age, days

136 kg

METHODS (Cont.)

Statistics Description

• Models: linear and non-linear regressions

• Close-out group was the experimental unit.

• Normally distributed and fitted linear models: ADG, FCR and days to final weight

• Non-normally distributed and non-linear models: mortality and off-grade pigs

• Goodness of fit of models

o Linear: RMSE and R-square

o Non-linear: Pearson test and the corrected Akaike Information Criterion (AICc)

WTF Mortality: what variables explain variation?

Weaning age and health status explain a great proportion of variation

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0.35

Weaning Age Health Status WeanDate Facility Type

Corr

elat

ion

coef

ficie

nt, r

Variables

**

*

WTF Mortality: impact of weaning age

0

5

10

15

20

25

17 18 19 20 21 22 23 24 25

Mor

talit

y, %

Weaning age, days

𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀 % = 𝐸𝐸𝐸𝐸𝐸𝐸 3.73 + (−0.092 × 𝑊𝑊𝑊𝑊𝑀𝑀𝑊𝑊𝑀𝑀𝑊𝑊𝑊𝑊 𝐴𝐴𝑊𝑊𝑊𝑊)

P < 0.001

WTF Mortality: impact of weaning age and health

0

1

2

3

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6

7

8

9

10

18 19 20 21 22 23 24

Mor

talit

y, %

Weaning Age, d18 19 20 21 22 23 24

Weaning Age, d

𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀 % = 𝐸𝐸𝐸𝐸𝐸𝐸 4.10 + (−0.109 × 𝑊𝑊𝑊𝑊𝑀𝑀𝑊𝑊𝑀𝑀𝑊𝑊𝑊𝑊 𝐴𝐴𝑊𝑊𝑊𝑊) 𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀 % = 𝐸𝐸𝐸𝐸𝐸𝐸 3.05 + (−0.061 × 𝑊𝑊𝑊𝑊𝑀𝑀𝑊𝑊𝑀𝑀𝑊𝑊𝑊𝑊 𝐴𝐴𝑊𝑊𝑊𝑊)

P = 0.003 P = 0.04

Poor health Good health

Δ = 0.87

Δ = 0.51

Δ = 0.42

Δ = 0.31

Growth rate: impact of weaning age

𝐴𝐴𝐴𝐴𝐴𝐴 𝑊𝑊 = 535.3 + (7.8 × 𝑊𝑊𝑊𝑊𝑀𝑀𝑊𝑊𝑀𝑀𝑊𝑊𝑊𝑊 𝑀𝑀𝑊𝑊𝑊𝑊)

P < 0.001

500

550

600

650

700

750

800

17 18 19 20 21 22 23 24 25

ADG

, g

Weaning age, d

18 19 20 21 22 23 24Weaning Age, d

620

640

660

680

700

720

740

760

18 19 20 21 22 23 24

ADG

, g

Weaning Age, d

Growth rate: impact of weaning age and health

𝐴𝐴𝐴𝐴𝐴𝐴 𝑊𝑊 = 504.2 + (9.3 × 𝑊𝑊𝑊𝑊𝑀𝑀𝑊𝑊𝑀𝑀𝑊𝑊𝑊𝑊 𝑀𝑀𝑊𝑊𝑊𝑊) 𝐴𝐴𝐴𝐴𝐴𝐴 𝑊𝑊 = 545.8 + (7.4 × 𝑊𝑊𝑊𝑊𝑀𝑀𝑊𝑊𝑀𝑀𝑊𝑊𝑊𝑊 𝑀𝑀𝑊𝑊𝑊𝑊)

P = 0.003 P = 0.04

Poor health Good health

WTF Mortality and off-grades: non-linear models

Parameters

Variables , % a b AICc Goodness of Fit (Pearson) Prob>ChiSq

Off-grade pigs 1.80 -0.044 419 0.0035 0.2321Mortality 3.73 -0.092 626 0.0004 <0.0001

Poor HealthOff-grade pigs 2.31 -0.064 284 0.0985 0.1630Mortality 4.10 -0.109 290 <0.0001 0.0026

Good HealthOff-grade pigs 1.66 -0.045 171 0.0008 0.5102Mortality 3.05 -0.061 385 0.5370 0.0387

𝑀𝑀 = 𝐸𝐸𝐸𝐸𝐸𝐸 𝒂𝒂 + (𝒃𝒃 × 𝑊𝑊𝑊𝑊𝑀𝑀𝑊𝑊𝑀𝑀𝑊𝑊𝑊𝑊 𝐴𝐴𝑊𝑊𝑊𝑊)

Growth performance: linear models

𝑀𝑀 = 𝒂𝒂 + (𝒃𝒃 × 𝑊𝑊𝑊𝑊𝑀𝑀𝑊𝑊𝑀𝑀𝑊𝑊𝑊𝑊 𝐴𝐴𝑊𝑊𝑊𝑊)

Parameters

Variables a b RMSE R-square P-value

Days to 136 kg 249.8 -2.0 10.139 0.1020 0.0006ADG, g 535.3 7.8 0.083 0.1083 0.0004FCR 2.854 -0.015 0.116 0.0437 0.0276

Poor HealthDays to 136 kg 259.0 -2.5 9.312 0.1445 0.0109ADG, g 504.2 9.3 0.075 0.1528 0.0087FCR 2.788 -0.011 0.140 0.0137 0.4495

Good HealthDays to 136 kg 246.2 -1.9 10.677 0.069 0.0211ADG, g 545.8 7.4 0.089 0.0756 0.0162FCR 2.701 -0.008 0.103 0.0139 0.3104

Rate of Change as weaning age increases (18-24 d)

Variable All Poor Health Good Health

Days to 136 kg -2.0 -2.5 -1.9

ADG, g 7.8 9.3 7.4

FCR -0.014 -0.011 -0.008

Off-grade pigs, % -0.11 -0.17 -0.09

Mortality, % -0.56 -0.68 -0.36

CONCLUSIONS

Weaning age and health status of the sow farm greatly impacted the life-time

performance of pigs overtime (2010 - 2014)

The negative impact of early weaning was more profound under health

challenge conditions (poor health)

On this “healthy” sow farm (few health challenge events) every additional

weaning day (18 to 24 d) reduced the mortality by 0.56% and improved the

growth rate of pigs by 7.8 g/d

THANK YOU!