Reproductive Decision Tree - Dr. Don Levis, Levis Worldwide Swine Consultancy, from the 2013 World Pork Expo, June 5 - 7, 2013, Des Moines, IA, USA. More presentations at http://www.swinecast.com/2013-world-pork-expo

1. Donald G. Levis, PhD
Levis Worldwide Swine Consultancy
Lincoln, Nebraska 68526
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2. Dr. Mark Estienne
Virginia Tech University
Dr. Wayne Singleton
Purdue University (retired)
Dr. Rodney Baker
Iowa State University
Dr. Tim Safranski
University of Missouri
Dr. William Flowers
North Carolina State Univ.
Dr. Rob Knox
University of Illinois
Dr. Ken Stalder
Iowa State University
Dr. Mark Knauer
North Carolina State Univ.
Committee chair: Dr. David Meisinger, USPCE
Lead Author: Dr. Don Levis, Levis Worldwide Swine Consultancy
Co-authors:
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3. The sponsors of this project are greatly
appreciated. Thanks!
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4. Reasons for development of the
troubleshooting guide:
• In the United States, the number of university “Extension”
people academically trained in reproductive physiology of
swine is small.
– Don Levis (University of Nebraska - retired, active
consultancy business)
– Wayne Singleton (Purdue University - retired)
– Mark Estienne (Virginia Tech)
– Rob Knox (University of Illinois)
• Universities have just about totally eliminated on-farm
visits and solving of reproductive problems.
• Get all the questions, answers, available publications, and
references related to reproductive problems of the swine
breeding herd in one location. 4

5. Objectives of the computer format and preparation
of the information
• Keep everything as simple as possible
Make the computer program highly user friendly
and as simple as possible (no fancy animation
stuff that takes up a lot of memory space)
Make the appearance of the information as
simple as possible
Answer the question in simple terms and provide
documentation for the answer
Search document for specific term
Have the information readily available to all pork
producers and allied industries.
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6. Select a main category for investigating a
problem with reproductive efficiency:
• Problems with replacement gilts
• Problems with sows
• Problems with semen quality
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Screen Level 1

7. Problems with replacement gilts
• Problem with puberty attainment and
expression of estrous
• Problem with gilt pool being too small
• Problem with low litter size
• Problem with low farrowing rate
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Screen Level 2

8. Problem with puberty attainment and expression
of estrous
• Workers need training in the proper procedures
for effectively detecting estrus in gilts [Blue Box
Button – has a publication on estrus detection]
• Gilts fail to exhibit first estrus or exhibit a first
estrus that is delayed. [33 questions]
• Gilts exhibit first estrus but stop cycling after one
or more estrous cycles. [25 questions]
• A high percentage of gilts (30 to 40% %) do not
exhibiting first estrus after treatment with P.G.
600 [19 questions]
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Screen Level 3

9. Problem with puberty attainment and expression
of estrous
• Gilts exhibit first estrus in response to P.G. 600 but stop
cycling after one or more estrous cycles. [25 questions]
• Gilts exhibit first estrus but then exhibit abnormal
estrous cycles. [25 questions]
• Gilts exhibit first estrus but then exhibit abnormal
estrous cycles after treatment with P.G.600.
[25questions]
• There is poor synchrony of first estrus among gilts. [22
questions]
• Gilts exhibit weak signs of first estrus; i.e, they stop
briefly for back-pressure-test and then run off. [15
questions]
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Screen Level 3 (continued)

10. There is poor synchrony of first estrus among
gilts.
• 1. Housing and Environment Questions
• Is there a large variation in the age and degree of sexual
maturation among potential replacement gilts?
• Are gilts at an appropriate age and body size to continue
expressing estrous cycles after first estrus?
• Were gilts exposed to boars prior to entering the breeding barn?
• Were gilts relocated and transported from rearing facilities to a
new location, such as the breeding barn?
• Were gilts mixed with contemporary gilts from other pens within
2 weeks before expected natural attainment of puberty?
• Were gilts exposed to ambient temperatures above 85 F?
• Were methods used to cool gilts when ambient temperature
was above 85 F? 10
Screen Level 3

11. There is poor synchrony of first estrus among gilts.
• 2. Boar Exposure Questions
• Are gilts at an appropriate age (165 to 180 days
old) and body size (240 to 260 pounds) to
respond to boar stimuli?
• Do all boars exhibit good libido when stimulating
gilts (i.e., chant, chomp, salivate, mount)?
• Do the gilts appear intimidated by the size
and(or) behavior of the boars used for
stimulation?
• Do gilts receive continuous (24 hours per day)
direct physical contact with a sterilized boar?
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Screen Level 3

12. • 2. Boar Exposure Questions (Continued)
• Do gilts receive direct physical contact only 5 days
per week with mature boar(s)?
• Do gilts receive direct physical contact 7 days per
week with the mature boar(s)?
• Do gilts receive direct physical contact 2 times per
day with mature boar(s)?
• Do gilts receive direct physical contact for at least 5
to 10 minutes per day with mature boar(s)?
• Do gilts receive continuous (24 hours per day) fence-
line exposure to mature boars?
• Do gilts receive fence-line exposure only 5 days per
week to mature boar(s)?
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13. • 2. Boar Exposure Questions (Continued)
• Do gilts receive a few minutes of fence-line
exposure 7 days per week with mature boar(s)?
• Do gilts receive fence-line exposure 2 times per
day to mature boars?
• Do gilts receive fence-line exposure for at least 5
to 10 minutes per day to mature boars?
• Are all boars used for gilts stimulation sexually
mature and at least 11 months of age?
• Are the gilts exposed to several different mature
boars when stimulating gilts to cycle?
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14. Are the gilts exposed to several different
mature boars when stimulating gilts to cycle?
It is likely that efficacy of the boar effect in stimulating gilts
to begin estrous cycle is enhanced if gilts are exposed to
several different mature boars rather than a single boar.
It is likely that there are differences among boars of similar
genetics and age in their ability to stimulate the onset of
puberty in gilts (Zimmerman et al., 1997). Indeed, there may
be differences in quantity or type of pheromones
emitted, level and frequency of their vocalizations, willingness
to sustain physical interactions with gilts, and/or libido.
Thus, it is recommended that gilts be exposed to several
different mature boars when attempting to stimulate estrous
cycles. Modern systems such as the boar exposure area
(BEAR) make use of multiple “teaser” boars housed in stalls
separating two pens used for stimulating gilts and detecting
estrus (Levis, 2010).
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15. 15
Levis, D. G. 2010. Gilt management in the BEAR system. Factsheet. Pork Information
Gateway. U.S. Pork Center of Excellence. National Pork Board. Des Moines, IA. PIG 08-
05-01.

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17. 17
Select a main category having a problem
with reproductive efficiency:
• Problems with replacement gilts
• Problems with sows
• Problems with semen quality
Screen Level 1

18. Problems with sows
• Sow longevity is too low due to high
replacement rate, culling rate, and lameness.
• Sows have a low farrowing rate.
• Sows have a low number of piglets born per
litter.
• Weaning-to-service interval is too long.
• Preweaning mortality is too high.
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Screen Level 2

19. Preweaning mortality is too high.
• Piglet mortality is high during farrowing and
first 24 hours after birth. [102 questions]
• Piglet mortality is high during days 2 to 3 after
birth. [50 questions]
• Piglet mortality is high after day 3 of birth to
weaning. [35 questions]
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Screen Level 3

20. Piglet mortality is high during farrowing and
first 24 hours after birth.
• 1. Sow care prior to farrowing [6 questions]
• 2. Day 1 pig care [19 questions]
• 3. Stillborn piglets [18 questios]
• 4. Crushing/lying on piglets [28 questions]
• 5. Litter size, birth weight and birth order [5
questions]
• 6. Mammary glands and piglet behavior [9
questions]
• 7. Savaging of piglets [11 questions]
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21. Example questions from Day 1 Pig Care
Are first born piglets marked and removed after stomach is
full (within 2 hours of birth)?
Piglets born later in the litter are at a competitive
disadvantage to those born early in the process. Colostrum is
produced by mammary glands accumulating antibodies and
immunoglobulins which are then dispensed with the milk
(Devillers et al., 2007; Foisnet et al., 2010; Markowska-Daniel
et al., 2010). As such, the quality of the colostrum decreases
as milk is nursed (Figure 1). Piglets born earlier in the birth
process who have achieved a full-stomach of colostrum can be
removed for 1.5 hours to assist later born piglets in getting a
large quantity of high quality colostrum (Figure 2 and 3). This
time should be recorded and piglets returned to the litter not
more than two hours later. Sows typically let milk down about
once an hour. It is undesirable to have piglets miss more than
one subsequent nursing event.
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22. 22
0
10
20
30
40
50
60
70
80
0 3 6 9 12 15 18 21 24
Hours after onset of farrowing
IgG,mg/mL
Measurement not taken
Figure 1. Colostrum concentration of IgG after onset of farrowing
(Foisnet et al., 2010)

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Figure 3. Accumulated full-stomach piglets.Figure 2. Full-stomach piglets

24. 2424
Select a main category having a problem
with reproductive efficiency:
• Problems with replacement gilts
• Problems with sows
• Problems with semen quality
Screen Level 1

25. Select the topic area concerning semen quality
and the possibility of lowering farrowing rate
• An analysis of records to indicate whether
semen quality could be lowering farrowing
rate [Blue Box]
• Receiving, storing, and handling commercial
or off-site boar stud semen at the sow farm
[37 questions]
• Collecting, processing, storing, and handling of
semen on the sow farm [51 questions]
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26. Example questions about semen quality
Was motility estimated on a 0 to 100% basis?
Sperm motility is generally estimated to the nearest
5% on a 0 to 100% basis. Because motility has an
effect on number of doses that can be made, it is an
advantage to estimate motility to the nearest 5%
for raw semen. Remember motility is influenced by
temperature and must be evaluated immediately
after the slide is properly prepared at 37 C (98.6 F).
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Link to motility videos: No. 1, No. 3, No. 4, and No. 6
Link to Singleton’s 2009 Sow Bridge Powerpoint presentation: On-farm semen
evaluation

27. Motility of sperm cells (video)
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28. Are there indications of bacterial contamination?
Semen agglutination is one visual indication of bacterial
contamination. Decreased storage life of semen, reduced female
fertility, vaginal discharges in mated females and in extreme cases
even female death may be associated with bacterial contamination.
Bacterial cultures should be negative at 24 hours incubation and no
significant growth after 48 hours is preferred. Semen is not sterile and
although bacterial inhibitors (antimicrobials) are added mishandling,
poor storage conditions, and prolonged storage can result in bacterial
proliferation.
[References button]
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29. Extremely bad case of bacteria in boar semen
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