dr. michael dyck - impact of the boar on herd fertility

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!!