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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.
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Impact of the boar on herd fertility
Leman - Reproduction WorkshopSept 15, 2012
Michael DyckGeorge Foxcroft, Jenny Patterson and Amanda Minton
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….
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)
Assessing Boar Fertility
Litter Size Data for 31 Boars
(minimum of 50 matings/boar)
Tony Chandrauk - Personal Communication
What is stopping us from achieving major gains in production efficiency by better utilizing our best boars?
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
Not all boars are created equal!
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
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.
Genetic Gains from AI?
• Short-term Gains
– Use fewer superior boars siring slaughter pigs
(John R. Cosgrove, Banff Pork Seminar, 1996)
(Pork Storks, Australia)
• Long-term Gains
– Reduced “genetic-lag” in nucleus-multiplier-
commercial pyramid
Nucleus
Multiplier
Sow Herd
Slaughter
How improve a litter’s value?
(Williams, SBMW 2011)
A high indexing terminal boar passes these traits on to his progeny.
3. Decreased mortality
1. Better feed conversion
2. Fewer days to market
Increase $$ per pig produced
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
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 doses2. Move whole system to 2B viable cells3. Move to 1B viable cells using PCAI
Characterize boar fertility using single-sire AI.
Characterize boar fertility using single-sire AI.
2 Billion2 Billion
Multiple breedings, standard AI
Multiple breedings, standard AI
• 50 Single sire matings per boar at a concentration of 2 Billion sperm
• Production characteristics measured:
- Pregnancy & farrowing rate- Litter size (total and alive)
Moving towards more efficient and improved AI ......
.......Evaluating the true potential of a boar
Single sireSingle sire
D30 Pregnancy & Farrowing Rate
32%
Relationship between d30 PR and FR
Characterize boar fertility using single-sire AI.
Characterize boar fertility using single-sire AI.
2 Billion2 Billion
Removals due to low production &
overall value.
Removals due to low production &
overall value.
2 Billion2 Billion
33%
Multiple breedings, standard AI
Multiple breedings, standard AI
Multiple breedings, standard AI
Multiple breedings, standard AI
Proven fertile boars
Single sireSingle sire
10-15%Characterize boar
fertility using single-sire AI.
Characterize boar fertility using single-sire AI.
2 Billion2 Billion
Multiple breedings, standard AI
Multiple breedings, standard AI
Single sireSingle sire
Unproven boars
Characterize boar fertility using single-sire AI.
Characterize boar fertility using single-sire AI.
2 Billion2 Billion
Removals due to low production &
overall value.
Removals due to low production &
overall value.
2 Billion2 Billion
33%
Removals primarily due to
overall value.
Removals primarily due to
overall value.
1 Billion1 Billion
33%
Multiple breedings, standard AI
Multiple breedings, standard AI
Multiple breedings, standard AI
Multiple breedings, standard AI
PCAI and/or Fixed Time InseminationPCAI and/or Fixed Time Insemination
Proven fertile boars
Single sireSingle sire Single sireSingle sireSingle sireSingle sire
Unproven boars
Factors contributing to the value of the boar
NPD
Pigs Produced
Farrowing Rate
Litter Size
EBV
NPD
Others? (survivability)
Contribution Index (CI)Value of pigs produced (estimated per 100 sows)
= Farrow rate * Born Alive * Index * Value (7¢/index point)
Ranking by Contribution Index (estimated per 100 sows)
Pregnancy Rate
Pregnancy Rate %
Pregnancy Rate
Removals due to fertility
Index
# boars Index CI PWB(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 concentration 33 125.3 1447.5 +1.1
PWB = pigs weaned / boarCI = Contribution Index
(Williams, 2011)
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 31Average index 115 + 118 + 123 123
# Sows/Gilts 40,000 = 40,000 = 32,000 8,000P/S/Y 25 + 25 = 25 25W-to-F losses 7% = 7% = 7% 7%
Total pigs 1,000,000 = 1,000,000 - 800,000 200,000Sold/year 930,000 = 930,000 - 744,000 186,000Value 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)
P/S/Y = 25.8 26.826.5
2 Billion2 Billion
1 Billion1 Billion
BOARS
(Williams, 2011)
Key Message
Strategically use genetically superior boars
Semen concentration
Number boars needed
Genetic index
$0.80 to $1.31 per pig
Future Directions: On-going Studies
Boar Fertility Parameters
Genotypic SNPProfile
Seminal Plasma Proteomic Profile
Genomic & Proteomic Markers of Boar Fertility
THANK YOU!!