David K. BishopDavid K. Bishop

dbishop@sampsoncc.edudbishop@sampsoncc.edu

Sampson Community CollegeSampson Community College

Small Litter Size: Describing Small Litter Size: Describing the Problem From The Farm’s the Problem From The Farm’s

PerspectivePerspective

Season: Physiological Season: Physiological ChangesChanges

In most animals, exposure to In most animals, exposure to conditions that cause the body conditions that cause the body temperature to increase causestemperature to increase causes

- a decrease in gonadotropins; and- a decrease in gonadotropins; and

- a decrease in feed intake.- a decrease in feed intake.

Lifetime Performance: Lifetime Performance: Genetics + Genetics +

EnvironmentEnvironment

8

10

12

14

1 2 3 4 5 6 7

Parity

Liv

ebor

n

29,000 gilts

Condition ScoresCondition Scores

Regular Patterns of introductionRegular Patterns of introduction

Some program for “Knotheads”Some program for “Knotheads”

Maximum performanceMaximum performance Fertility- Typical measures Fertility- Typical measures

Farrowing Rate Farrowing Rate

Born-AliveBorn-Alive

Fecundity- Maximum Pigs per mating Fecundity- Maximum Pigs per mating

Avoid the negative impacts of “outliers”Avoid the negative impacts of “outliers”

Dealing with Weaned Sows: “as Dealing with Weaned Sows: “as Delivered” Delivered”

•Gilts / Sows that are/go Anestrus

•Weaned sows that Fail to return within 7 days

•Chronic Embryo Losses after Preg Check

•Timing Issues due to intensity of expression

•Improper use of hormonal therapy

Reproductive Failures Reproductive Failures Associated with Animal Associated with Animal

WelfareWelfare

Effect of ambient temperature on lactation feed intake and body weight loss

0

2

4

6

8

10

12

14

64.4 71.6 77 80.6 84.2

Ambient temperature, F

Avg

. d

aily

fee

d

inta

ke,

lbs

0

10

20

30

40

50

60

70

80

90

Bo

dy

wei

gh

t lo

ss,

lbs

ADFI (Far to wean) Body wt. Loss, lbs

J. Anim. Sci. 77:2124-2134, 1999.

11.910.8

9.9

6.8

12.5

Effect of Lactation Lenth on Weaner (1st Service) Farrowing RAte -All Farms

0%

20%

40%

60%

80%

100%

120%

0 5 10 15 20 25 30 35 40

Lactation Days

Maximize Lactation Length on Sows for subsequent Litter Size as long as she has enough Body Condition

to Initiate Cycles when Weaned

50556065707580859095

100

P0 P1 P2 P3

Far

row

ing

Rat

e (%

)

Control Late a Vs. b P < .05 c Vs. d P < .01

a b c d

The Effect of Late Insemination on The Effect of Late Insemination on Farrowing RateFarrowing Rate

10.911.6

9.410.5

6

8

10

12

14

16

Total Born Born Alive

Pig

lets

Bor

n

Control Late

a Vs. b (P < .05)

a b a b

The Effect of Late Insemination on The Effect of Late Insemination on Litter SizeLitter Size

The benefits of multiple AI are lost when the last The benefits of multiple AI are lost when the last AI is performed during too late.AI is performed during too late.

Sows with Lower fertility have:Sows with Lower fertility have: Susceptible to infections (at or before mating)Susceptible to infections (at or before mating) Decreasing uterine contractility (poor semen movement Decreasing uterine contractility (poor semen movement

from the AI bag)from the AI bag) Physiological post-breeding inflammatory response (16-Physiological post-breeding inflammatory response (16-

84 hours after mating)84 hours after mating) Higher incidence of Late returns to Estrus (< 3:1 Ratio)Higher incidence of Late returns to Estrus (< 3:1 Ratio)

The Effect of a Late Subsequent AI The Effect of a Late Subsequent AI on Reproductive Performanceon Reproductive Performance

Figure 4. Predicted Impact of Parity on the Wean to First Service Interval

y = 0.0253x2 - 0.3741x + 8.5813

p < 0.0008; R2 = 0.00224

7.00

7.20

7.40

7.60

7.80

8.00

8.20

8.40

0 2 4 6 8 10 12 14

Parity

Wea

n t

o F

irst

Ser

vice

In

terv

al (

Day

s)

AI in Swine: Proposed Role of Post-breeding AI in Swine: Proposed Role of Post-breeding Inflammation for Late AIInflammation for Late AI

CervixCervix

InflammatoryInflammatory

ProductsProducts

Late AILate AI

PMNsPMNs

C` & HSF

C` & HSF

******

******

- SP- SP

+ SP+ SP

Uterine ContractionsUterine Contractions

VesselsVesselsEndometriumEndometrium

Predictability of < 7 Born Predictability of < 7 Born AliveAlive

Large Scale operation for one yearLarge Scale operation for one year

Litters < 7 varied from 5 % to 22%Litters < 7 varied from 5 % to 22%

Placed average of 11 pigs per sowPlaced average of 11 pigs per sow

If sow lost 2 pigs (7-14 days) --If sow lost 2 pigs (7-14 days) --34% had < 7 born alive in next litter34% had < 7 born alive in next litter

If the reason was scours---If the reason was scours---68% had < 7 in subsequent litter68% had < 7 in subsequent litter

Farrowing Rate: Born-AliveFarrowing Rate: Born-Alive

0

2

4

6

8

10

12

14

16

18

20

75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95

Mandate

Deviations

Response

Effective Management Style

Typical Born-alive per RoomTypical Born-alive per Room

16 11 8 10 12 11 23 11 10 9 14 12 15991112

10 15 9 11 12 10 9 11 11 12 14 10 1518131624

0 4 0 0 5 6 10 14 11 11 12 13 122423

13 7 12 10 9 8 11 13 11 10 13 11 10118912

85% of Group = 11.91: 100% of Group = 10.54