Dr. Ken Stalder - Genetic and Management Methods to Improve Reproductive Efficiency in Sows

Genetic and Management Methods to
Improve Reproductive Efficiency in
Sows
Allen D. Leman Swine Conference:
Pre-Conference Program

University of Alberta-University of Minnesota
Reproduction Workshop:

12 - September - 2012
Ken Stalder, PhD
Professor & Extension Swine Specialist
Iowa State University, Ames

IOWA STATE UNIVERSITY
Department of Animal Science

Introduction
Pork producer profits are constrained
Increased feed costs
Increased labor costs
Increased regulatory issues
Areas where production efficiency can be
improved should be continually evaluated.
Remain competitive with other protein food
sources
Remain competitive with other producers world-
wide

Increased Cost of Production
Feed costs have impacted pork production
in many ways.
Grow – finish cost of production
Gilt development costs
If feed costs had remained low and price high – Positive
NPV attained within P1 or P2
Increased feed costs – Positive NPV attained ~ P3
 Really high feed costs – Positive NPV will not be attained until
feed costs decline or market price increases


Sow Longevity Value
Commercial producers and genetic
suppliers are recognizing the value of sow
longevity.
Value of retaining sows in the breeding herd for a
greater number of parities.
Many contributing factors leading to a sow
leaving the breeding herd earlier than farm
management desires.


Complexity of Sow Length of Productive
Life
 Involvement of
 Genetics
 Environmental
 Caretaker skills or stockmanship
 Gilt development
 Gilt conformation
 Fecundity
 Nutrition
– Gilt development
– Gestation
– Lactation
 Health
 Housing
– Pen vs. crated environment
– Flooring
 Behavior
 Seasonal effects
 Cull sow market price


Introduction
Many of these topics are not well
researched particularly when modern
housing systems and genetics are taken
into consideration.


Incidence of failure to breed, lameness and culling for old
age, in the sows according to litter parity Dagorn & Aumaitre, 1978

100
90
 Similar findings have been
Cumulated percentage of culled sows

reported in a more recent
80
70
60
50
40
popular press article in the
30
20
US
10
0
 Conclusion very similar to
those previously presented
1 2 3 4 5 6 7 8 9 10 >10
Number of litters per sow

Failure to breed Lameness Old Age Other  Challenging data
 Retrospective data
 Reported vs real reason
sows are removed


Characterization of U.S. Midwestern cull
sows
Examined > 3,100 cull sows at harvest
Obtained data from two harvest plants
Farm production data from ~ 1,000 animals
available
Objective
Characterize physical and reproductive
conditions of cull sows from U.S. Midwestern sow
harvest plants


U.S. cull sow study- data collection
 Traits measured
 Foot lesions (presence or absence)
 Front pad lesions
 Rear pad lesions
 Front cracked toes
 Rear cracked toes
 Front digital overgrowth
 Rear digital overgrowth
 Front missing dew claws
 Rear missing dew claws
 Front abscesses
 Rear abscesses


U.S. cull sow study- results
Pad lesions- rear 67.5%, front 32.9%


Cracked toes- front 22.6%, rear 18.1%


 Sows with front cracked toes compared to
sows without tended (P = 0.07) to have
fewer pigs born alive/day/herd life (0.0703
vs. 0.0725)
 equates to ~0.8 pigs/sow/year


Digital overgrowth- rear 21.1%, front 3.5%


 Sows with rear digital overgrowth in
comparison to sows without had
 fewer (P < 0.05) pigs born alive in last litter (0.54)
 tendency (P = 0.06) for decreased pigs born
alive/day/herd life (0.0702 vs. 0.0724)


 Traits measured
 reproductive tract evaluation
 ovary status

normal- 84.7%

acyclic- 9.0%

cystic- 6.3%
 pregnant- 5.9%


 Traits measured
 shoulder lesions
 none- 82.7%
 abrasions- 12.5%
 open wounds- 4.8%


 Sows with shoulder
lesions had 2.01 fewer
(P < 0.05) lifetime pigs
born alive compared
to sows without
shoulder lesions


 Traits measured
 Systematic lesions
 Pneumonia- 9.7%
1-10% lung involvement from pneumonia- 5.0%

10% lung involvement from pneumonia- 4.7%

 Pleural adhesions- 5.6%
 Peritonitis- 1.7%
 Other- < 1%


 A higher percentage of lung involvement
from pneumonia tended (P < 0.10) to be
associated with higher producing sows
(lifetime pigs born alive, pigs
born/day/herd life)


 Traits measured
 Teeth
 top teeth number
 bottom teeth number
 wear
minimum- 10.5%
moderate- 47.0%
severe- 42.5%


 Sows with severe teeth wear in
comparison to sows without had
 fewer (P = 0.06) pigs born alive in last litter (0.44)
 fewer (P < 0.01) pigs born alive/day/herd life
(0.0704 vs. 0.0734)


U.S. cull sow study- culling reasons
Parity

1,2 3,4 5,6 7,8 9+

Farm culling code n= 198 n= 145 n= 219 n= 201 n= 160

Body condition, % 11.6 (2)a 15.2 (3) 9.6 (5) 7.5 (3) 5.6 (3)

Old age, % 1.5 (6) 4.1 (6) 21.5 (2) 65.7 (1) 83.8 (1)

Lameness, % 10.6 (3) 17.9 (2) 11 (4) 5.5 (4) 0.6 (6)

Other, % 7.1 (4) 10.3 (4) 8.2 (6) 5.5 (4) 1.3 (5)

Poor litter performance, % 6.1 (5) 6.2 (5) 19.6 (3) 2.5 (6) 2.5 (4)

Reproduction, % 63.1 (1) 46.2 (1) 30.1 (1) 13.4 (2) 6.3 (2)
a
Rank of culling code within parity group.


U.S. cull sow study- reproductive failure
 No heat most frequent farm culling code
in parity 1 (41.1%)
 Did not conceive most common in parities
2 to 5 (39.2, 36.5, 25.4, and 27.4%,
respectively)
 Of the sows culled for reproductive
failure, 86.2% were classified as having
normal ovaries


U.S. cull sow study- summary
U.S. cull sows evaluated at harvest had foot,
reproductive, shoulder, and systemic lesions
Body condition was associated with multiple
abnormal conditions of sows
Several conditions were associated with reduced
sow performance parameters (lifetime pigs born
alive, pigs born alive in last litter, pigs born
alive/day/herd life)
The majority of low parity sows were culled for
reproductive failure, but ovaries were normal in
appearance


Genetic Effects on Sow Longevity
Study designed to estimate the
phenotypic and genetic associations of
gilt compositional and structural
soundness traits with reproductive and
longevity traits
Determine factors measured or evaluated
early in a sow’s life that are associated
with superior sow productive lifetime.
 Data collected through at least parity 5

The study involved 1447 females from two
commercially available genetic lines.
Gilts were on average 190 days of age and
124 kg body weight at the time of body
composition and structural soundness
evaluation.
National Pork Board Funded project


Traits evaluated
Compositional traits
Body weight,
Loin muscle area,
10th rib backfat, and
Last rib backfat.


 Reproductive traits evaluated
 Lifetime total number born,
 Lifetime number born alive,
 Number born alive per lifetime days, and
 Percentage productive days from total herd days.
 Lifetime, herd days and removal parity were considered as
longevity traits.


Means and heritability estimates for lifetime reproduction traits in study evaluating the
relationship between compositional, structural soundness, reproductive performance
and productive lifetime in commercial lines of sows.

REML
Mean ± s.e. Mean ± s.e. P-valuea h² ± s.e.
Lifetime reproduction Across genetic
Grandparent line Parent line lines
Lifetime total number
born 40.94 ± 1.74 46.01 ± 1.31 0.04 0.16 ± 0.06
Lifetime number born
alive 37.71 ± 1.62 41.17 ± 1.14 0.04 0.17 ± 0.06
LBA/Lb 0.040 ±
0.036 ± 0.001 0.001 0.005 0.16 ± 0.06
PD%c 58.22 ± 1.48 62.79 ± 0.95 0.01 0.14 ± 0.06


 ~ 70% of the females were removed prior to the sixth parity. At
the termination of data collection,
 14% of the females were still alive and in production at the
commercial sow herd.
 Reproductive failure was the most frequent culling reason during
the first three parities and it caused the loss of 16% of the
research females before the fourth parity.
 Culling for lameness or feet and leg problems primarily occurred
prior to the third parity causing the removal of 7.5% of the young
females.


Heritability Estimates
 Longevity traits 0.12 to 0.16
 Lifetime reproduction traits 0.13 to 0.17
 Compositional traits 0.50 - 0.70
 Body structure traits 0.11 - 0.34
 Leg structure traits 0.07 - 0.29
 Greatest heritability estimates were obtained for weak front and rear pastern postures 0.28 and
0.29, respectively.

 Overall leg action 0.12


Genetic Effects on Sow Longevity Genetic
Correlation Estimates
Most were low and non-significant (P > 0.05)
Larger loin muscle area was significantly
associated with greater lifetime, removal
parity and lifetime number born
Less upright rear legs were associated with
greater lifetime born alive per day of life and
percentage of productive days and
intermediate rear foot size with greater
lifetime and removal parities.


Sow Longevity and Genetic Progress
Relationship
 Replacement and culling decisions should not be
influence by the genetic progress occurring in the
maternal lines from their genetic supplier.
 Under the most optimistic genetic improvement
situations, a sow would not be replaced until the 6 th or 7th
parity.
 This represents the parities where the value of the
genetic progress that has occurred for maternal and
growth traits is equal to or greater than the gilt
development variable costs.


Sow Longevity and Genetic Progress
Relationship
 The parity at which gilt development variable costs and
the genetic progress value are equal defines the number
of parities that commercial breeding herds should cull
sows for old age.
 Under realistic genetic improvement values, the
cumulative value for the genetic improvement made
across the traits is equal to the gilt development costs
to at least the 10th parity or greater.
 Genetic issues should not enter into culling /
replacement decisions for breeding herd sows


Summary
Many factors contribute to the ability of a
sow to have a long and productive herd
life.
These factors include genetic and
environmental issues.
A renewed focus on sow nutrition
research is warranted.


Summary
Many traits genetically correlated with
sow productive lifetime and can be
improved through selection.
We cannot ignore the people factor on any
production process including pork
production.
Caretaker skills / stockmanship /
management ability, effects on the sow
productivity cannot be underestimated.

Dr. Ken Stalder - Genetic and Management Methods to Improve Reproductive Efficiency in Sows

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