David K. BishopDavid K. Bishop
[email protected]@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