Impact of the Boar on Herd Fertility - Dr. Michael Dyck, University of Alberta, from the 2012 Allen D. Leman Swine Conference, September 15-18, St. Paul, Minnesota, USA.

1. Impact of the boar on herd fertility
Michael Dyck
George Foxcroft, Jenny Patterson and Amanda Minton
Leman - Reproduction Workshop
Sept 15, 2012

2. Not all boars are created
equal……
A single sperm is half a
pig …………it probably
requires < 1 thousand
sperm at the site of
fertilization to produce
a litter….

3. Assessing Boar Fertility
Reproductive Performance
– Despite “rigorous” semen evaluation, certain boars
do not have the same reproductive performance
– Routine semen evaluation standards (> 70% motility
& < 30% abnormal sperm) detect male reproductive
disorders…..
…… but do not predict relative fertility among
“acceptable”, healthy sires
(Flowers et al. 1997; Alm et al. 2006; Ruiz-Sanchez et al. 2006)

4. Litter Size Data for 31 Boars
(minimum of 50 matings/boar)
Tony Chandrauk - Personal Communication

5. Not all boars are created equal!
What is stopping us from achieving major gains in
1. An inability to determine relative fertility of boars
with high genetic merit when used with low numbers
of sperm per AI dose.
2. Use of pooled semen from boars with different, but
largely unknown, “relative” fertility.
3. Limited application of advanced AI technologies with
semen from superior boars

6. Limitations of using Pooled Semen
Certain boars have lower fertility if numbers of sperm
per AI dose are reduced (say < 2 billion)
Therefore, “diluting” sperm numbers of more fertile
boars within a pool with sperm from boars that
produce few offspring at lower sperm doses is an
ineffective strategy when trying to maximize the
impact of AI

7. Limitations of using pooled semen
Use of pooled semen breaks the link
between known genetic value of
individual boars and the paternity of
progeny produced.

8. Genetic Gains from AI?
• Short-term Gains
(Pork Storks, Australia)
– Use fewer superior
boars siring slaughter
pigs
Nucleus • Long-term Gains
Multiplier
– Reduced “genetic-lag” in
Sow Herd
nucleus-multiplier-
Slaughter
commercial pyramid
(John R. Cosgrove, Banff Pork Seminar, 1996)

9. How improve a litter’s value?
A high indexing terminal boar
passes these traits on to his progeny.
1. Better feed conversion
2. Fewer days to market
3. Decreased mortality
Increase $$ per pig produced
(Williams, SBMW 2011)

10. On-going Studies:
Large scale field studies:
•Boar fertility evaluated with “low” semen doses
⁻ 2 billion sperm/AI dose
⁻ Minimum of 50 AI matings
•All boars genotyped for Single Nucleotide Polymorphisms
⁻ Porcine SNP60 BeadChip (Illumina Inc., USA) to assess 62,163
SNPs per animal
•Proteomic analysis of seminal plasma
⁻ Seminal plasma protein profiles for boars with “High” & “Low”
fertility assessed by 2D electrophoresis

11. Steps for Improved AI programs
1. Identify boars with acceptable fertility
• Characterize boar fertility using Single-Sire matings
2. Eliminate boars with for limited reproductive
capacity at lower sperm doses (2 billion)
3. Use boars with proven fertility at lower sperm
doses (1 - 1.5 billion) for PC-AI
4. Retain boars with the highest EBVs for
producing commercial progeny

12. Collaborative Trial
• Holden Farms & University of Alberta
• Objective: Decrease semen concentration per AI dose
to improve the use of genetically superior boars
Phases of the trial:
1. Prove boars at entry with single-sire matings (SSM)
at 2B viable cells using multiple doses
2. Move whole system to 2B viable cells
3. Move to 1B viable cells using PCAI

13. Moving towards more efficient and
2 Billion improved AI ......
Characterize boar .......Evaluating the true potential of
fertility using
single-sire AI. a boar
• 50 Single sire matings per boar at a
concentration of 2 Billion sperm
• Production characteristics measured:
- Pregnancy & farrowing rate
- Litter size (total and alive)
Single sire
Multiple breedings,
standard AI

14. D30 Pregnancy & Farrowing Rate
32%

15. Relationship between d30 PR and FR

16. Unproven boars Proven fertile boars
2 Billion 2 Billion
Characterize boar
fertility using
Removals due to
10-15%
single-sire AI.
low production &
33% overall value.
Single sire Single sire
Multiple breedings, Multiple breedings,
standard AI standard AI

17. Unproven boars Proven fertile boars
2 Billion 2 Billion 1 Billion
Characterize boar Removals due to Removals
fertility using low production & primarily due to
single-sire AI. overall value. overall value.
33% 33%
Single sire Single sire Single sire
Multiple breedings, Multiple breedings, PCAI and/or Fixed
standard AI standard AI Time Insemination

18. Factors contributing to the value of the boar
EBV Farrowing
Rate
Pigs
NPD
Produced
Litter
Size
NPD
Others?
(survivability)

19. Contribution Index (CI)
Value of pigs produced (estimated per 100 sows)
= Farrow rate * Born Alive * Index * Value (7¢/index point)

20. Ranking by Contribution Index (estimated per 100 sows)

22. Pregnancy Rate

23. Pregnancy Rate %

24. Removals due to fertility
Pregnancy Rate

25. Index

26. PWB
# boars Index CI
(base = 0)
All Boars (entered stud) 66 121.4 1312.0 -
Structural/behavorial 8 123.1 1323.3 +0.1
Substandard Sperm Production 7 120.0 1172.4 -1.5
Low fertility (PR <90%) 8 119.5 1066.5 -2.4
Boars Remaining 43 121.9 1394.8 +0.9
Phase 2 – further decrease
33 125.3 1447.5 +1.1
concentration
PWB = pigs weaned / boar
CI = Contribution Index

27. Economics for Holden Farms: (40,000 Sows)
AI method Standard Standard PC-AI (Sows) Standard (Gilts)
AI dose (billion) 3 ¯ 2 ¯ 1 2
# Inseminations 2.4 = 2.4 ¯ 2.4 2.4
# boars needed 231 ¯ 155 ¯ 61 31
Average index 115 + 118 + 123 123
# Sows/Gilts 40,000 = 40,000 = 32,000 8,000
P/S/Y 25 + 25 = 25 25
W-to-F losses 7% = 7% = 7% 7%
Total pigs 1,000,000 = 1,000,000 - 800,000 200,000
Sold/year 930,000 = 930,000 - 744,000 186,000
Value per pig $0.07 = $0.07 = $0.07 $0.07
$416,640 $104,160
$7,486,500 $7,681,800 $8,007,300
Annual Opps: $195,300 $520,800
(Diff 2 & 3B) (Diff PC-AI sows & 3B and gilts 2 & 3B)
(Williams, 2011)

28. 2 Billion
1 Billion
P/S/Y = 25.8 26.5 26.8
BOARS

29. Key Message
Strategically use genetically
superior boars
Semen concentration
Number boars needed
Genetic index
$0.80 to $1.31 per pig
(Williams, 2011)

30. Future Directions: On-going
Studies
Boar Fertility
Parameters
Genotypic SNP Seminal Plasma
Profile Proteomic Profile
Genomic & Proteomic Markers
of Boar Fertility

31. THANK YOU!!