Miranda Smit

PhD candidate

University of Alberta

Saskatchewan Pork Industry Symposium 2012

Content Background information on litter size and litter quality

Effect of litter birth weight on individual growth performance

Repeatability of litter birth weight in sows

How to increase the number of quality piglets weaned?

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

Management after weaning

Take home messages

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:

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

Sow parity Total pigs born Pigs born dead

Pigs born live Adjusted litter size 48 h after farrowing

7 20 6 14 12 2 15 2 13 13 5 19 5 14 11 2 15 1 14 11 9 14 1 13 12 5 13 0 13 12 4 19 1 18 13 2 12 0 12 12 5 13 1 12 10 5 18 0 18 11 4 16 1 15 12 1 10 2 8 12 4 16 0 16 12 5 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.

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)

Av

era

ge

bir

th w

eig

ht

pe

r litt

er

(kg

)Litter size vs. average birth weight

N=5290 (Smit 2007)

Low/High groups represent ~ 30% of population

16.7

43.838.8

0

10

20

30

40

50

P2-3 P4-6 P7+

% o

f S

ow

s W

ith

Gre

ate

r

tha

n 2

5 C

L's

bb

a

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

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

Ove

rall p

erc

en

t (%

)

Embryo/Fetus No.

D30 D50

(Patterson et al., 2008)

Number of embryos / fetuses

Ove

rall

% o

f li

tter

s

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

0 5 10 15 20 2510

15

20

25

30

35(a)

Average number of viableembryos

Av

era

ge

pla

ce

nta

lw

eig

ht

(g)

0 5 10 15 20100

150

200

250

300

350

400(b)

Average number of viablefetuses

Day 30

(R2 = -0.37; P < 0.001)

Day 90

(R2 = -0.45; P = 0.001)

Low litter birth weight due to: 3. Limited placental development from D30 of gestation

onwards

(Town et al., 2004)

Low litter birth weight due to:

1. High ovulation rates (>25 ovulations)

2. Intrauterine Crowding (IUC) in early gestation

3. Limited placental development from D30 of gestation onwards

4. Measurable effects on fetal development by D50 of gestation onwards

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

Duodenal mucosal height

(Alvarenga et al., 2012)

High bw Low bw

At birth

At 150-d old

Postnatal development ofmyofiber number and myofiber thickness

Age, wk

0 10 20 30 40

Tota

l myo

fiber

num

ber,

x 1

06

0.0

0.5

1.0

1.5

2.0

Myo

fibe

r d

iam

ete

r,

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).

Effects of intra-uterine crowding

Bérard et al., 2010

crowded crowded crowded control control control

Muscle fiber characteristics of the Psoas Major muscle

Intra-uterine crowding (IUC)

Reduces myofiber numbers; regardless of birth weight

This constraint may reduce the lean growth potential of the offspring of the entire litter!

Impact on production systems?

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

Increased variation in pig market weights

Slow growing pigs need to stay in barn longer to hit carcass weight targets

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

Litter size vs average birth weight

y = -0.0255x + 1.74 R² = 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

Ave

rag

e l

itte

r b

irth

we

igh

t (k

g)

Litter size (total born)

Low bw group Medium bw group High bw group

Litter average birth wt. vs placental wt.

y = 0.1229x + 0.078 R² = 0.22 P<0.001

0

0.1

0.2

0.3

0.4

0.5

0.8 1.3 1.8 2.3

Ave

rag

e p

lace

nta

l w

eig

ht

(kg

)

Litter average birth weight (kg)

Brain-sparing effects

Brain: R² = 0.29 P<0.001

Liver: R² = 0.75 P<0.001

Small intestine: R² = 0.77 P<0.001

Muscle: R² = 0.68 P<0.001

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

0

10

20

30

40

50

60

70

80

90

100

0.4 0.9 1.4 1.9 2.4

Mu

scle

we

igh

t (g

)

Tis

sue

we

igh

t (g

)

Individual birth weight (kg)

brain weight liver weight Intestine weight muscle weight

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

Mo

rta

lity

(%

)

Pig

s b

orn

(n

)

Low bw

High bw

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)

Body Weight till 149 days

0.000.200.400.600.801.001.201.401.601.802.00

BW

, kg

Birth, kg

5.4

5.6

5.8

6

6.2

6.4

6.6

6.8

Bo

dy

Wt

(kg)

Weaning - 21d

18

19

20

21

22

23

Bo

dy

Wt

(kg)

nursery - 65d

88

90

92

94

96

98

100

Bo

dy

Wt

(kg)

149d

0.56 Kg difference

6.92 Kg difference

0.81 Kg difference

3.05 Kg difference

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

AD

G (

g)

Time period

ADG

Low BW

Medium BW

High BW

0

0.5

1

1.5

2

2.5

3

3.5

1 2 3 4 5 6 7 8 9 10F

CR

(g

/g)

Time period

Feed Efficiency

Low BW

Medium BW

High BW

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

The repeatability concept

0.0

0.5

1.0

1.5

2.0

2.5

3.0

0 5 10 15 20 25

Ave

rage

bir

th w

eig

ht

of

litte

r

Total born

Knol, 2010

Repeat measures of the two extreme sows for

litter average birth weight are plotted.

Farrowing 1

Farrowing 2 0

10

20

30

40

50

60

70

80

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

Low

Medium

High

Classification and percentage of sows having a low, middle, or high litter birth weight phenotype at farrowing 1

% o

f so

ws

afte

r se

con

d f

arro

win

g in

b

irth

w

eigh

t p

hen

oty

pe

clas

sifi

cati

on

s

Repeatability within sows

Repeatability within sows

Number of farrowings

N Correlation (R) Repeatability (R2) P-value

1 farrowing 523 0.44003 0.19363 <0.0001

2 farrowings 301 0.48422 0.23447 <0.0001

3 farrowings 134 0.50442 0.25444 <0.0001

Farrowing 1 Farrowing 2 Farrowing 4 Farrowing 3

• 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 higher parity sows to guide selection for optimal lifetime productivity

Sow selection traits

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.

• Segregate sows into farrowing rooms based on expected birth weight phenotype.

Implications at sow level

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

• Use AI strategies (high litter survivability boars) to mitigate effects of the low birth weight litter phenotype

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

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

4.05 5.63

17.53

1.49

4.25 5.90

18.28

0

5

10

15

20

D1 oflactation

D14 oflactation

D21 -Weaning

End ofnursery

CON FP10

P<0.1

We

igh

t (k

g)

P<0.1

P<0.05

(Smit et al., 2012)

• 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 Fat Pak - High in DHA) during rebreeding, gestation and lactation

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

Set up of research trial

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

We

igh

t (k

g)

Average Weight - Nursery Data

Control

Gromega

N = 48 pens / trt

Overall P-values: Trt: 0.12 Time: <0.001 Trt * Time: 0.15

Effect of n-3 PUFA on body weight

0

10

20

30

40

50

60

70

Start 1 2 3

Period

Bo

dy

We

igh

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: <0.001 Trt * Time: 0.17

Overall P-values FE (G/F): Trt: 0.07 Time: <0.001 Trt * Time: 0.09

* Significantly different at P < 0.05

•No effect on ADG, ADFI and FE

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 with fixed 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

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’t

get 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

Grow-Finish performances and budgets

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

Low birth weight litters: same feed efficiency, so same amount of feed. BUT: slower growth, so switch to different phase at a later age.

Separate flow for low and high birth weight litters improves possibility to feed to different needs of both groups

Selling strategies Low and High bw pigs can be sold to different

markets;

Ham market

Japanese market

European market

Each market has different optimal weight, fat and lean percentage

Conclusions for litter management

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

Identify litters in lactation and wean to separate locations

Adjust nutrient requirements to reflect expected lean growth potential

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

Pigs born in low birth weight litters grow slower and need 9 more days to reach the same market weight as high 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 and decreases time to market by 5 days

N-3 PUFA supplementation to sows with predicted low birth 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 in high and low birth weight litters

Acknowledgements Financial supporters