Dr. George Foxcroft - Risk Factors For Sow Culling

RISK FACTORS FOR SOW CULLING.

George Foxcroft University of Alberta, Edmonton, Alberta

Sow Lifetime Productivity Breakout Session2015 Leman Conference

Sow performance continues to improve in terms of more pigs weaned/sow/year

Early trends were for increased total born to be negatively associated with total weaned and birth weight

Focus of recent selection programs and the Sow Lifetime Productivity (SLP) initiative now moving to production of “quality weaned pigs”

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

Limiting Factors for SLP: The early removal of young sows from the herd.

(Lucia et al., 2000, Engblom et al., 2007, Hughes et al., 2010)

• 40-50% of sows culled before 3rd parity• 15-20% sows only produce one litter• 10% never farrow a litter 65% of these culls can be attributed to

reproductive disorders or failure• 42% of females culled for reproductive reasons are

gilts At least 3 litters required before there is

positive cash flow to a producer (Lucia et al. 2000; Stalder et al., 2003)

(Spörke, 2007)

RISK FACTORS FOR SOW CULLING.

George Foxcroft University of Alberta, Edmonton, Alberta

Sow Lifetime Productivity Breakout Session2015 Leman Conference

PROACTIVE MANAGEMENT FOR IMPROVED SOW LIFETIME

PRODUCTIVITY

The Blueprint Team National Hog Farmer, April 2015

Sow Lifetime Productivity Breakout Session2015 Leman Conference

Blueprint Series: Sow potential productivity captured for life - George Foxcroft, Univ. Alberta

Birth weight, neonatal management and sow longevity potential - Billy Flowers, NC State

Growth and nutrition effects on gilt development – Jeff Vallet, USDA, Clay Center, NE

Does floor space allowance during rearing impact future reproduction? - Mark Estienne and Stuart Callahan, Virginia Tech

Management of the gilt for breeding and in first gestation for longevity - Rob Knox, Univ. Illinois

Building structure for late-parity sows - Joe Stock and Ken Stalder, Iowa State

First lactation management - Nathalie Trottier, Michigan State

The purpose of the Blueprint series was to look at different aspects of gilt and sow management from three perspectives

Firstly, how do producers identify gilts in early development that have the greatest potential for retention in the breeding herd and for achieving excellent SLP? Secondly, what key management practices promote retention and increase the number of quality weaned pigs?Finally, at different levels of the production cycle, what are the key risk factors for decreased SLP and what key performance benchmarks can be identified to offset these risks? 

Key reasons for sow removal from the herd

“Research funded by the Pork Checkoff and other studies clearly show that early parity sows leave the breeding herd for either reproductive failure (encompassing numerous reproductive issues such as failure to cycle, failure to conceive, failure to farrow, and other reproductive issues), or feet and leg soundness and locomotion issues. Most sows are culled after parity 3 for other reasons. Therefore, to get more sows reaching the later parities we need to focus on the issues that cause their removal in parities 1 through 3, viz. reproductive failure and feet and leg soundness”. 

Joe Stock and Ken Stalder, Iowa State University

Consistent supply of quality gilts

Focus on early breeding period

Involuntary vs voluntary culling

Key considerations for improved SLP:

1. Consistent supply of quality gilts

Selection of known cyclic gilts (recorded heat-no-serve event) optimized with purpose-designed gilt development unit (GDU)

External signs of internal problems?

The vulva should be relatively large with nothing appearing infantile or under developed as that may indicate an underdeveloped internal reproductive system.

Producers should also be able to recognize the “masculinized” vulva that is occasionally seen in gilts that have an abnormal ovo-testis development of the gonads. 

Joe Stock and Ken Stalder, Iowa State University

Joe Stock and Ken Stalder, Iowa State University

SRDP, 2011

HoldingPen

Boar Exposure Area (BEAR)

Record keeping is critical!

Selecting gilts with greatest fertility• Data suggest the response to boar stimulation can be used

to identify the 75 – 80% of gilts that are likely to be most fertile over their productive lifetime.• Higher percentage of gilts bred of those delivered to the sow farm• Higher percentage farrowed to first service

• Treatment with PG600 is an effective tool to meet GDU and breed targets, once served, no detrimental effects to Parity 4

• Data suggests that gilts that do not response to boar stimulation or PG600 treatment in 28 days should not be considered eligible for breeding• Fewer will be served, and never farrow a litter• However, those that are bred, will have similar response to “Select

gilts” over 4 parities

Distribution of age at puberty

Vallet 2015

Early

Mid

Late

Select Non-Select

Distribution of age at puberty for NAT and PG600-induced gilts.

Early- Responders

Mid- Responders

Late- Responders

NaturalPG600

Reproductive, weight and growth rate characteristics of NAT and PG600 heats. Characteristic

NAT

(n = 2,654)

PG600

(n = 821)P-Value

Age at stimulation (d) 163.6 ± 0.8 163.4 ± 0.8 0.5365

Age at puberty (d) 178.4 ± 0.9 189.8 ± 0.9 <.0001

Days from stimulation to puberty 14.9 ± 0.3 26.4 ± 0.4 <.0001

Weight at puberty (kg) 120.5 ± 0.6 126.3 ± 0.6 <.0001

Growth rate at puberty (kg/d) 0.677 ± 0.004 0.667 ± 0.004 <.0001

Age at service (d) 222.6 ± 1.3 223.2 ± 1.4 0.1337

Estimated estrus at first service (d) 3.1 ± 0.05 2.6 ± 0.05 <.0001

Overall retention rates across successive parities within the breeding herd  Classification

  NAT PG600

Nos. delivered to sow farm 2,374 741

Nos. (%) served of delivered 2318 (97.6) a 709 (95.7) b

Rates as % gilts

deliveredRates as % gilts bred

  NAT PG600 NAT PG600

P1 Pregnancy rate (first serve) 96.3a 93.8 b 98.6 98.0

P1 Farrowing rate (first serve) 94.7 a 92.0 b 97.0 96.2

P1 Farrowing rate (multiple

serves)96.3 a 94.1 b 98.6 98.3

Farrowing rate at P2 87.6 85.0 89.7 88.9

Farrowing rate at P3 79.2 76.7 81.1 80.1

Farrowing rate at P4 70.6 a 65.3 b 72.3 c 68.3 d

Total born by parity and total pigs born over 4 parities NAT and PG600-induced heats in the GDU

2. Focus on early breeding period

Thoughts on the impact of birth weight and pre-weaning growth rate“There is still much to be learned about the optimal environment to which replacement gilts should be exposed from birth to weaning. However, it does appear that understanding relationships between birth weight, colostrum intake and pre-weaning growth will prove to be useful in creating management systems that consistently produce sows with enhanced lifetime productivity. A consideration of birth weight in conjunction with litter of origin might prove to be the starting point upon which future decisions are made”.

Billy Flowers, North Carolina State University

Targets for Body State at Breeding

• 2nd or 3rd estrus• Weight: 135-150 kg

• Growth rate: > 600 g/d & < 790 g/d

68.8 68.5

61

56

58

60

62

64

66

68

70

130-150 151-170 171-200

Ret

entio

n by

3 p

ariti

es (

%)

Breeding weight (kg)

Source: Amaral Filha, unpublished data (2008)

AI @211 d143 kg

AI @219 d160 kg

AI @225 d177 kg

0

2

4

6

8

10

12

14

16

130-150 151-170 171-200

Cul

ling

Rea

son

(%)

Breeding weight (kg)

Locomotion Reproductive Other

a

b

c

Effect of Breeding Weight on Retention Rate to 3rd Parity

Relationship between average lifetime growth rate at puberty and age at puberty

In today’s current genotypes, growth rate not limiting (only 8% of all gilts were at risk of slow growth rates (<0.60 kg/d).

National Pork Board, 2014 SLP Project

Challenges – are the fastest growing gilts too heavy at breeding?

National Pork Board, SLP Project

Associations between growth performance, puberty induction and lifetime productivity in gilts

Growth rate group < 0.600 0.600-0.750 > 0.750

n 285 2,729 266

Puberty

Age (d) 186.4 ± 0.9a 181.0 ± 0.8b 174.8 ± 1.0c

Growth rate (kg/d) 0.571 ± 0.003a 0.675 ± 0.002b 0.775 ± 0.003c

Weight (kg) 106.9 ± 0.7a 122.1 ± 0.5b 135.4 ± 0.7c

Service

Age (d) 228.1 ± 1.4a 222.5 ± 1.3b 219.0 ± 1.4c

Retention rate of delivered

Served (%) 96.7 ± 1.1 97.3 ± 0.3 96.5 ± 1.1

Farrow to 1st service (%) 93.4 ± 1.6 94.2 ± 0.5 92.6 ± 1.6

Farrow parity 2 (%) 88.1 ± 2.1 87.1 ± 0.7 84.9 ± 2.2

Farrow parity 3 (%) 76.5 ± 2.7 79.0 ± 0.8 77.2 ± 2.6

Farrow parity 4 (%) 70.0 ± 2.9 69.7 ± 0.9 67.6 ± 2.9

Total born

Parity 1 13.7 ± 0.2 13.6 ± 0.1 13.7 ± 0.2

Parity 2 12.9 ± 0.2 13.2 ± 0.1 13.3 ± 0.2

Parity 3 13.9 ± 0.2 13.9 ± 0.1 13.6 ± 0.3

Parity 4 14.2 ± 0.2 14.2 ± 0.1 14.1 ± 0.3

Growth rate to 160 d vs age at natural first estrus

National Pork Board – SLP project – Vallet et al.

As suggested for several years, feeding our gilts to appetite is an increasing problem because of their high growth rates.

Can nutritional strategies be used to address this problem?

Early lactation management to maximize lifetime milk production

Lactation management affects lifetime mammary gland function

Nathalie L. Trottier, Michigan State

The impact of leaving a gland unsuckled for 24 hours from day 1 to day 2 of lactation on piglet average daily gain, and the continued effect thereafter up to day 28 of lactation.

Nathalie L. Trottier, Michigan State

3. Involuntary vs voluntary culling

Key reasons for sow removal from the herd

Research funded by the Pork Checkoff and other studies clearly show that early parity sows leave the breeding herd for either reproductive failure (encompassing numerous reproductive issues such as failure to cycle, failure to conceive, failure to farrow, and other reproductive issues), or feet and leg soundness and locomotion issues. Most sows are culled after parity 3 for other reasons. Therefore, to get more sows reaching the later parities we need to focus on the issues that cause their removal in parities 1 through 3, viz. reproductive failure and feet and leg soundness. 

Joe Stock and Ken Stalder, Iowa State University

Joe Stock and Ken Stalder, Iowa State University

Joe Stock and Ken Stalder, Iowa State University

Q: How many gilts and sows are culled for poor reproductive performance (no estrus, not pregnant, etc.) when in fact lameness was the primary issue?

Effective culling strategies for poor reproductive performance.

Q: If excellent retention rates to second parity are possible, should first parity sows not returning to estrus be culled? What is the actual productivity of these sows if they are finally bred?

Q: What are the most reliable criteria for culling because of low litter size born?

AFNS

14.5-14-

13.5-13-

12.5-11.5-

11-10.5-

10-9.5-

9-8.5-

8-7.5-

7-1 2 3 4 5 6 7 8

Aver

age

born

aliv

e

Parity

(Peralta y Bustamnie, 1998, redrawn from Martin Rillo, 2001)

AFNS

12 -

11.5 -

11 -

10.5 -

10 –

9.5 –

9 –

8.5 –

8 -

1 2 3 4 5 6 7 8

Aver

age

born

aliv

e

Parity

(Edwards, 1997; redrawn from Martin Rillo, 2001)

Ranking based on second litter size

Acknowledgments:

Holden Farms Inc. Murphy Farms LLCNational Pork Board