optimal litter size – increasing the number of quality pigs weaned

8/19/2019 Optimal Litter Size – Increasing the Number of Quality Pigs Weaned

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Miranda Smit

PhD candidate

University of Alberta

Saskatchewan Pork Industry Symposium 2012


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Content

Background information on litter size and litter quality

Effect of litter birth weight on individual growthperformance

Repeatability of litter birth weight in sows How to increase the number of quality piglets weaned?

Effect of omega-3 fatty acid supplementation to sowson growth performance of piglets from low birth weight litters

Management after weaning

Take home messages


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Introduction Starting selection on sow prolificity : ’70s

Extension to production herds: ‘90

9.0

9.5

10.0

10.5

11.0

11.5

12.0

12.5

13.0

13.5

14.0

92 93 94 95 96 97 98 99 0 1 2 3 4

Year

Total born

Born alive

Weaned

Boulot et al., 2008

Ethical impact:


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(Data are from personal communication, Leveneau, P.)

Sow parity Total pigs bornPigs borndead

Pigs born live Adjusted litter size48 h afterfarrowing

7 20 6 14 12

2 15 2 13 135 19 5 14 11

2 15 1 14 119 14 1 13 12

5 13 0 13 12

4 19 1 18 132 12 0 12 125 13 1 12 10

5 18 0 18 11

4 16 1 15 121 10 2 8 124 16 0 16 125 18 3 15 11

8 22 5 17 11

5 13 7 6 12

Production data recorded for individual hyperprolific, white-type,

sows from commercial units in Brittany, France.


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y = -0.038x + 1.9484

R2 = 0.2336

0

0.5

1

1.5

2

2.5

0 2 4 6 8 10 12 14 16 18 20

Litter Size (total # of piglets born)

A v e r a g e b i r t h w e i g h t p e r l i t t

e r ( k g )

Litter size vs. average birth weight

N=5290 (Smit 2007)

Low/High groups represent ~ 30% of population


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16.7

43.8

38.8

0

10

20

30

40

50

P2-3 P4-6 P7+ %

o f S

o w s W i t h

G r e a t e r

t h a n 2 5 C L

' s

bb

a

Low litter birth weight due to:1. High ovulation rates (Patterson et al., 2008)


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Low litter birth weight due to:

0.0%

2.0%

4.0%

6.0%

8.0%

10.0%

12.0%

14.0%

16.0%

18.0%

20.0%

4 5 6 8 9 10 11 12 13 14 15 16 17 18 19 20 21 23 28

O v e r a l l p e r c e n t ( % )

Embryo/Fetus No.

D30 D50

(Patterson et al., 2008)

Number of embryos / fetuses

O v e r a l l % o

f l i t t e

r s

2. Intra-Uterine Crowding (IUC) in early gestation


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0 5 10 15 20 25

10

15

20

25

30

35(a)

Average number of viableembryos

A v e r a g e p l a c e n t a l

w e i g h t ( g )

0 5 10 15 20

100

150

200

250

300

350

400(b)

Average number of viablefetuses

Day 30

(R 2 = -0.37; P < 0.001)

Day 90

(R 2 = -0.45; P = 0.001)


3. Limited placental development from D30 of gestation

onwards

(Town et al., 2004)


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1. High ovulation rates (>25 ovulations)2. Intrauterine Crowding (IUC) in early

gestation

3. Limited placental development from

D30 of gestation onwards4. Measurable effects on fetal

development by D50 of gestationonwards

• What are the consequences of low litter birth weight on post-natal performance?


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Duodenal mucosal height

(Alvarenga et al., 2012)

High bw Low bw

At birth

At 150-d old


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Postnatal development of myofiber number and myofiber thickness

Age, wk

0 10 20 30 40

Totalmyofib

ernumber,x1

06

0.0

0.5

1.0

1.5

2.0

Myofiber

diameter,

m

0

20

40

60

80

Myofiber number

Myofiber diameter

Representation of the relative time points postnatally at which the

number of myofibers (red, broken line) and myofiber size (blue,

unbroken line) cease to contribute to the increase in muscle mass.(Rhefeldt et al. 2000).


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Effects of intra-uterine crowding

Bérard et al., 2010

crowded crowded crowdedcontrol control control

Muscle fiber characteristics of the Psoas Major muscle


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Intra-uterine crowding (IUC)

Reduces myofiber numbers; regardless of birth weight

This constraint may reduce the lean growthpotential of the offspring of the entire litter!

Impact on production systems?

Possible reduced growth rates and efficiency of IUC pigsto market wt. NOT JUST SMALL PIGS

Increased variation in pig market weights

Slow growing pigs need to stay in barn longer to hitcarcass weight targets


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JBS United Inc. research farms, Indiana; 222 sows , Parity 2 to 7 Piglets weighed and tagged within 24h after birth

Litters of 9 to 16 total born characterized by birth weight

Litter size Low bw group (kg) High bw group (kg)

9 < 1.34 > 1.80 10 < 1.34 > 1.92 11 < 1.30 > 1.78

12 < 1.31 > 1.73

13 < 1.28 > 1.72 14 < 1.22 > 1.62

15 < 1.20 > 1.60

16 < 1.26 > 1.58

Low = 1 SD below litter size mean High = 1 SD above litter size mean

Growth performance of different litter

phenotypes


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Litter size vs average birth weight

y = -0.0255x + 1.74R² = 0.04 P=0.01

0.5

0.7

0.9

1.1

1.3

1.5

1.7

1.9

2.1

2.3

8 9 10 11 12 13 14 15 16 17

A v e r a g e

l i t t e r

b i r t

h w e i g h t ( k g )

Litter size (total born)

Low bw group Medium bw group High bw group


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Litter average birth wt. vs placental wt.

y = 0.1229x + 0.078R² = 0.22 P


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Brain-sparing effects

Brain:R² = 0.29 P


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Pre-weaning performance

11.3

1.3

12.5

0.9

16.4

6.7

0

2

4

6

8

10

12

14

16

18

0

2

4

6

8

10

12

14

Born alive Stillborn Pre-wean mortality

M o r t a

l i t y

( % )

P i g s

b o r n

( n )

Low bw

High bw


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Characterization of growth performance

All pigs weaned into conventional nursery

Pigs penned by litter birth weight classification

At least 9 pens per birth weight classification

26 pigs/pen (mixed sex) Common feeding program

Nutrients above determined herd requirements

Pig weights and feed intake by pen throughout growth

period Individual pig weights at weaning and at market

Carcass information by pen (Tyson Fresh Meats;Logansport, IN)


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Body Weight till 149 days

0.000.200.40

0.600.801.001.201.401.601.802.00

B W ,

k g

Birth, kg

5.4

5.6

5.86

6.2

6.4

6.6

6.8

B o d y W t ( k g )

Weaning - 21d

18

19

20

21

22

23

B

o d y W t ( k g )

nursery - 65d

88

90

9294

96

98

100

B o d y W t ( k g )

149d

0.56 Kg

difference

6.92 Kg

difference

0.81 Kg

difference

3.05 Kg

difference


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ADG and FCR Wean-Finish

0

0.2

0.4

0.6

0.8

1

1.2

1 2 3 4 5 6 7 8 9 10

A D G ( g

)

Time period

ADG

Low BW

Medium BW

High BW

0

0.51

1.5

2

2.5

3 3.5

1 2 3 4 5 6 7 8 9 10

F

C R ( g / g )

Time period

Feed Efficiency

Low BW

Medium BW

High BW


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Carcass quality

Low BW Medium BW High BW

Live weight, kg 115.86 116.23 116.18

Hot carcass weight, kg 88.13 88.64 87.78

Age at market (days) 174.6 170.9 165.7

Loin depth, mm 71.12 71.63 70.87

Fat depth, mm 16.76 15.49 14.73

Lean meat content, % 56.00 56.36 56.48

Grade Premium, $ 5.79 6.20 6.18

Sort loss, $ -0.93 -0.90 -0.80

Marketed at fixed end weight


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The repeatability concept

0.0

0.5

1.0

1.5

2.0

2.5

3.0

0 5 10 15 20 25

A v e r a g e b i r t h

w e i g h t o f l i t t e r

Total born

Knol, 2010

Repeat measures of the two extreme sows for

litter average birth weight are plotted.


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Farrowing 1

Farrowing 2 0

10

20

30

40

50

60

7080

Low (16%) Medium (65%) High (19%)

LowMedium

High

Classification and percentage of sows having a low, middle, or high

litter birth weight phenotype at farrowing 1

% o

f s o w s a f t e r s e c o n d f a r r o w i n g i n

b i r t h

w e i g h t p h e n o t y p e c l a s s i

f i c a t i o n s

Repeatability within sows


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Repeatability within sows

Number of

farrowings

N Correlation (R) Repeatability (R 2) P-value

1 farrowing 523 0.44003 0.19363


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• Select for “uterine capacity”:• Numbers born live, not total born• Mean litter birth-weight• Quality (survivability) of the pigs born

• Include phenotypic data from litters of higherparity sows to guide selection for optimal lifetime productivity

Sow selection traits


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Boar selection traits

High bw Low bw

Observe the germ cells (G), the nuclei of the Sertoli cells (S), Leydig cells(L), and presence of cell division (M: mitosis). Bar represents: 30 µm.


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• Segregate sows into farrowing rooms based onexpected birth weight phenotype.

Implications at sow level

• Use AI strategies (low litter size boars) to limitintra-uterine crowding in early gestation

• Use AI strategies (high litter survivability boars) to

mitigate effects of the low birth weight litterphenotype

• Target nutritional interventions at sows with apredicted low litter birth weight phenotype


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Effect of O3FA on piglet growth Feeding O3FA to gilts/sows during rebreeding, (parts of)

gestation and lactation improved piglet growth after birth.(Rooke et al., 2001, Rooke et al., 2000; Mateo, 2007)

1.44

4.055.63

17.53

1.49

4.25

5.90

18.28

0

5

10

15

20

D1 of lactation

D14 of lactation

D21 -Weaning

End of nursery

CON FP10

P


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• Collaborative trial – JBS United/Univ. Alberta

• Ranked sows at weaning based on average birth weight of past 3 litters, then pair-matched and fed

diets with or without n-3 PUFA (Gromega/Sow FatPak - High in DHA) during rebreeding, gestationand lactation

• Evaluate offspring performance to market andcarcass merit of low average birth weight litters

Set up of research trial


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Effect of n-3 PUFA on body weight

0

2

4

6

8

10

12

14

16

18

20

Weaning Week 1 Week 3 Week 5

W e i g h t ( k g )

Average Weight - Nursery Data

Control

Gromega

N = 48 pens / trt

Overall P-values:Trt: 0.12Time:


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Effect of n-3 PUFA on body weight

0

10

20

3040

50

60

70

Start 1 2 3

Period

B o

d y W e i g

h t ( k g

)

First half of grow-finish phase

50

60

70

80

90

100

110

120

130

3 4 5 6

Period

Second half of grow-finish phase

Control

Gromega

*

*

Aimed to market at fixed end weight

Overall P-values FE (G/F):Trt: 0.04 Time:


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Effect of n-3 PUFA on carcass traits

CON (n=44) GRO (n=47)

Live weight, kg 126.2 128.9

Hot carcass weight, kg 95.0 97.0

Age at market, days 152.3 151.4

Expected age at market withfixed weight of 127 kg

155.7 150.2

Loin depth, mm 70.3 70.3

Fat depth, mm 18.4 19.1

Lean meat content, % 55.4 55.2

Grade Premium, USD 6.36 6.39

Sort loss, USD -1.09 -1.36


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Nursery performance and budgets

Expensive nursery diets overfed to population that

doesn’t need it Large birth weight litters will start better and will have a

reduced need for prestarter and nursery phase 1 $0.40 – 0.80/pig reduced cost for heavy litters Approximately $0.10/pig savings on a herd basis (17% of

litters of high birth weight).

Slower growing pigs with reduced G.I. tract mass don’tget budget of early starters Reduced performance of 20% in early nursery Mortality, reduced growth rate, antibiotic injections Cost - ?? Could be $1-4/pig on this light population Approximately $0.50/pig on a herd basis in lost performance

G Fi i h f d


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Grow-Finish performances and

budgets

High birth weight litters: faster growth, so fasterswitch to different phase

Low birth weight litters: same feed efficiency, so

same amount of feed. BUT: slower growth, so switch todifferent phase at a later age.

Separate flow for low and high birth weight littersimproves possibility to feed to different needs of both

groups


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Selling strategies

Low and High bw pigs can be sold to differentmarkets;

Ham market

Japanese market

European market

Each market has different optimal weight, fat andlean percentage


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Conclusions for litter management

Low average litter birth weight results in slowergrowth and lower carcass quality of pigs

Identify litters in lactation and wean to separatelocations

Adjust nutrient requirements to reflect expectedlean growth potential

Market progeny of different birth-weight litters atdifferent market weights or different ages


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Pigs born in low birth weight litters grow slower and

need 9 more days to reach the same market weight ashigh birth weight litters

Litter average birth weight is repeatable within sows

N-3 PUFA supplementation to sows in gestation and

lactation improves body weight of their offspring anddecreases time to market by 5 days

N-3 PUFA supplementation to sows with predicted lowbirth weight litters will improve body weight of this

group, which will decrease the variation in body weight in the grow-finish phase between pigs born inhigh and low birth weight litters


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Acknowledgements

Financial supporters

optimal litter size – increasing the number of quality pigs weaned

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