Improving Efficiencies of Replacement Gilt Management - Jennifer Patterson, from the 2018 Allen D. Leman Swine Conference, September 15-18, 2018, St. Paul, Minnesota, USA. More presentations at http://www.swinecast.com/2018-leman-swine-conference-material

1. Leman Swine Conference
“Gilt Management as the Driver of Sow Lifetime Productivity”
September 17th, 2018
Improving efficiencies of
replacement gilt management
Jennifer Patterson & George Foxcroft

2. In the industry today……
 Sow performance has improved over last few years,
2-3 more pigs/sow/year (Pigchamp benchmarking)
 Most of the improvement has been in litter size and
farrowing rate (Pigchamp benchmarking)
• Genetic improvement
• Improved production practices
• Implementation of gilt management programs
 In recent years, focus has been on achieving
optimal performance through improving sow
lifetime performance.
(Spörke, 2007; http://www.pigchamp.com/benchmarking/benchmarking-summaries)

3. Sow Lifetime Productivity
“The total number of quality pigs weaned
during the productive lifetime of a female;
from the time she becomes breeding eligible
until she leaves the herd”
National Pork Board, 2010
replacement gilts produced
….. Of the multiplication sow
 Longevity  ProductivityPollmanand Hostetler, 2018

4. Limiting factors for sow lifetime productivity:
 Retention rate:
• The greatest source of variation is the early removal of
young sows from the herd. (Lucia et al., 2000, Engblom et al.,
2007, Culbertson, 2008, Hughes et al., 2010)
• 10% never farrow a litter, 15-20% sows only produce
one litter, 40-50% of sows culled before 3rd parity
 Reproductive failure:
• ~ 40-65% of culls can be attributed to reproductive
disorders or failure (Engblom 2008; Hughes 2008)
• 42% of females culled for reproductive reasons are gilts
 Non-productive days:
• 70% of non-productive days (NPD) are due to re-service
and culling intervals (Koketsu, 2005).

5. “New” limiting factors for sow lifetime productivity:
 Low individual gilt birth weight
(Magnabosco, Cunha, et al., 2015: Magnabosco, Benardi et al., 2015)
• Carries risks for poor early survival & post-natal growth
• Carries risks for limited repro tract development
 A repeatable “low litter birth weight” phenotype at
nucleus and multiplication level
• Carries all the risks above as a “litter” trait
• Limits the efficiency of genetic transfer in the herd
• Carries a trans-generational “environmental” risk for
low birth weight in terminal line litters
 Are high birth weight gilts an increasing problem for
SLP?

6. Pre-Select 1
Confirmation
 14+ teats  Health
 Structure  Growth
 Litter of origin
• Sow phenotype
• Lactation mmgt
Birth -Weaning
Final Select
~ 170 - 200 d
-125% of req’s enter
-Direct boar contact
80% estrus in 28 d
+5-10% Non-Selects
Pre-Select 2
~ 140 d
Confirmation
 14+ teats
 Health
 Structure
 0.6 kg/day
Breed Group Mmgt
100% breed targets met
100% Select Gilts
100% bred at target weight
100% bred at 2nd–3rd estrus
Feed mmgt before breeding
STAGES OF A GILT REPLACEMENT
PROGRAM
Genetics, health programs, nutrition, quality of floor and slats, air flow and
temperature, stocking density, PEOPLE and biosecurity ~ Dr. Gonzalo Castro (2018)
A gilt becomes a potential
replacement female at birth!

7. 1. “Litter of origin” is a key factor determining the
efficiency of replacement gilt production and Sow
Lifetime Productivity (SLP)
2. Effective gilt selection programs (puberty
stimulation and recorded heats) resolve many SLP
issues
• Select the most fertile gilts
• Maintain a consistent supply of service eligible gilts
• Appropriate management of body weight at breeding
An efficient replacement gilt management
program will recognize the following key
components:

8. High pre-weaning
morality.
Low retention of gilts through selection
program.
Low efficiency of
replacement gilt
production
Poor growth
performance of low
birth weight progeny.
Poor lifetime production.
Poor response to boar exposure.
Services per week not
met.
Poor synchrony of
first estrus among
gilts.
Gilts are too heavy, too old at puberty.
High non-productive days.
Delayed onset of
estrus.
Poor retention to 3rd parity.
High replacement rate.
Low first litter size.
Late return to estrus after 1st weaning
Poor performance in
1st lactation.
1. Low Individual
Birth Weight/Low
Litter Birth Weight
phenotype
2. Failure to
maintain a
consistent supply of
service eligible gilts
3. Failure to select
the most fertile
gilts
4. Inappropriate
management of
body state/feed
intake at breeding
Common reproductive issues that may arise….
….Can result from failure to address the
key components of GDU management.

9. 1. “Litter of origin” is a key factor
determining the efficiency of replacement
gilt production and Sow Lifetime
Productivity (SLP)

10. Birth weight phenotype as a limiting factor for SLP:
Within litter variation
Sow Sow
Birth weight phenotypevs
Entire litters
of low birth
weight pigs
Low birthweight
High birthweight
Av TB = 14
Av litter BW = 1.4 kg

11. Low repeatable
birthweight
High repeatable
birthweight
Parity
2 3 4 5 6 2 3 4 5 2 3 4 4 5 6 7
(kg)
Birthweight phenotype is repeatable:

12. The effect of “litter of origin”
on sow lifetime productivity
Litter of origin as key factor determining SLP
Animals:
• 1096 L3 sows at the multiplier
• Litter birthweight phenotype determined on 694
sows on at least 3 litters
• >47,000 piglets weighed
• >7550 L42 gilts with known litter of origin were
individually tagged
Minnesota and Iowa
Measurements:
• All culling and mortality recorded for every tagged
gilt from birth to removal
• All production records for 3 parities recorded

13. 3
6
9
12
15
18
21
24
0.7
0.9
1.1
1.3
1.5
1.7
1.9
2.1
1
30
59
88
117
146
175
204
233
262
291
320
349
378
407
436
465
494
523
552
581
610
639
668
Averagetotalborn
Litteraveragebirthweight(kg)
Sow
Average birth weight (at least 3 parities) Average TB
Birth weight classification:
LOW
<1.18 kg
LOW – MEDIUM
1.18-1.37 kg
MEDIUM – HIGH
1.37 – 1.6 kg
HIGH
>1.6 kg
(39.0%)(43.2%)(9.7%) (8.1%)

14. Sows that exhibit a repeatable “Low” birth weight”
phenotype at multiplication level:
 Produce many of the small pigs born
 Have low gilt retention rates
 Produce fewer “select” gilts
 Negatively impact post-natal growth potential of
progeny
 Pass these traits onto their progeny

15. Sows that exhibit a repeatable “Low” birth weight”
phenotype at multiplication level:
 Produce many of the small pigs born
 Have low gilt retention rates
 Produce fewer “select” gilts
 Negatively impact post-natal growth potential of
progeny
 Pass these traits onto their progeny
 Using effective gilt stimulation programs, there was
little impact of low birth weight phenotype
 on puberty attainment in “pre-selected” gilts.
 on retention rate or litter size to parity 4

16.  Determine sow phenotype early on maternal sows
(weigh litters or individual pigs).
 Culling sows with a repeatable low LBW phenotype at
the nucleus/multiplication level will increase:
 the efficiency of the genetic transfer program,
 the number of select gilts produced per sow bred.
 Impose a minimum birth weight for all replacement
gilts?
 Use strategies to increase weaning weight?
Strategies to improve efficiency of low birth weight
phenotype sows:

17. Sows that exhibit a repeatable “High” birth
weight” phenotype at multiplication level:
 Produce gilts with high post-
natal growth potential
 Retention rates to selection
are high but risk of
exceeding upper target
weight for breeding is also
high
 Produce replacement gilts that may have
compromised SLP due to early culling

18. Strategies to improve efficiency of high birth weight
phenotype sows:
 Find ways to limit the high growth potential of many
gilts during development.
 Minimize weight at breeding by implementing
efficient GDU programs that minimize “entry to
service” intervals.

19. 2. Effective gilt selection programs (puberty
stimulation and recorded heats) resolve
many SLP issues

20. 1. Failure to select the most fertile
gilts
2. Failure to maintain a consistent
supply of service eligible gilts
3. Inappropriate management of body
weight at breeding
Key risk factors in GDU management

21. Early
Mid
Late
Select
Gilts naturally cyclic after
30 days of boar exposure
are “Select” gilts.
Identifying “Select” gilts
Non-Select
Additional “opportunity” gilts
could enter the herd if needed
Vallet, 2015

22. “Select” gilts have improved SLP vs “Non-Select”
• Inseminated earlier & have fewer NPD
• Gilts expressing early puberty, have an increased
percentage of return to estrus within 10 d after
weaning (youngest vs oldest 1/3)
• Culled less due to reproductive problems
• Higher farrowing rate, more pigs born alive & longer
reproductive life
• Boar exposure method and time to pubertal
response have lasting effects on sow performance
and retention rate (Knox et al., 2018)
Sterning et al., 1998; Koketsu et al., 1999; Schukken et al., 1994; Patterson et al.,
2010; Saito et al.. 2011, Kaneko and Koketsu, 2012, Roongsitthichai et al., 2013

23. Implementation of gilt stimulation programs Record Keeping!!
Time
Point
Action: group by group
D1-13
 Direct (and fenceline) contact with
vasectomized boars
D14  Remix all non-cyclic gilts
D23
 “Opportunity” (known non-cyclic) gilts
without HNS receive PG600
D28
 All eligible gilts are identified
 Gilts without HNS are culled
BoarExposureArea
(BEAR)
Directcontactwith
highlibidoboars
Dedicatedand
trainedstaff
Key components of efficient GDU programs

24. 0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
-7 -5 -1 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35
Accumulativepercent(%)
Days to puberty after first boar exposure
77.6 % of
gilts in heat
after 28 days
of puberty
stimulation
& PG600 trt
National Pork Board, 2014 SLP Project
Days to puberty after first exposure to the boar
~ starting from a pen average of 170 d of age.
Only deliver gilts with
a recorded HNS to the
sow farm
Key components of efficient GDU programs

25. Appropriate management at service
• 2nd or 3rd estrus
• Weight: 135-150 kg
• Growth rate: > 600 g/d & < 790 g/d
• Feed intake 14 days prior to service
Key components of efficient GDU programs

26. Are your GDU protocols limiting
the efficiency of replacement gilt
management in your herd?
What can you do at the various stages of development to improve efficiency?

27.  Determine sow phenotype early on maternal sows (weigh
litters or individual pigs).
 Post-farrowing (Day 1) care:
• Reduce chilling/hypothermia
• Ensure adequate colostrum ingestion
 Strategic cross fostering of replacement females – reduce
size of lactation litter
 Minimum birth weight of all replacement gilts?
When do you starting managing your
replacement gilts?





28. What are your facilities like? What do you have for
boar power? Do you have trained and motivated staff?

29. Do we count the
cost of these 45
NPDs when
considering SLP?
What is the cost of
adding Non-Select
gilts to the herd?
What are your GDU protocols? Are they measurable?

30. Select
What are your gilt selection targets?
~95% of gilts will cycle in 100 days…. BUT….
Non-Select
Vallet, 2015
85% 90% 95% 100%

31. Is variation the norm we deal with?
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 57 60 63 66 69
Days to HNS
AccumulativePercentage
1 2 3
4 5 6
7 8 9
10 11 12
13
These groups –”before PRRS
These groups – “clinical PRRS”
These groups -"
2004 - Pipestone
Season?
Health?
Management?
Feed?
Mycotoxins?

32. What is your weight at service?
Estimated weight at service (kg)
Target service
weight

33.  If you don’t measure it, you can’t manage it.
 Records! Record the data and analyze the results.
What records do you keep?
Accumulative % attaining puberty by group
Weight at HNS (lb)



34.  If you don’t measure it, you can’t manage it.
 Records! Record the data and analyze the results.
• Are using available reports from your herd mgt software?
What records do you keep?


Arrival to first service interval
0-10 11-20 21-30 31-40 41-50
First services 472 425 122 42 13
Percent served 43 38.7 11.1 3.8 1.2
Observed Heats (Gilt first services)
Total
services
Repeat
rate
Farrow
Rate
Conception
Rate
Average
liveborn
0 145 8.2 - - -
1 510 3.6 - - -
2 2 0 - - -
Weight at first service
<270 270-300 300-350 >350
First services 0 0 0 0

35.  If you don’t measure it, you can’t manage it.
 Records! Record the data and analyze the results.
 Tailor the results to your farm.
 Benchmark to improve performance.
What records do you keep?

Accumulative % attaining puberty by group
Weight at HNS (lb)




36. Conclusions:
1. Implementing GDU programs that identify
“select” gilts with the greatest reproductive
potential is an essential part of improving SLP.
2. Rigorous pre-breeding management protocols
are needed to limit non-productive days and
control weight at breeding.

37. Thank-you to the National
Pork Board for their support.
• Holden Farms
– Nick Holden
– Matt Allerson
– Aaron Hanson
– Elaine Triemert
– Staff at study farms
• UofA /UI/NCSU students
• Juan-Carlos Pinilla
Acknowledgments: