Prevalence and Risk Factors for Postpartum Anovulation in Dairy

Cows

Robert Walsh

November 30, 2006

Outline

• Resumption of Ovarian Activity– Identification of at Risk cows

– Cow-level risk factors

– Herd-level risk factors

• Questions

Outline

• Resumption of Ovarian Activity

0 5 10 15 20 25 30 35 Calving Ovulation

DIM

16

14

12

10

8

6

4

2

0

Fol

licle

dia

met

er (

mm

)Resumption of Ovarian Activity

All follicles present at birth

Follicle development divided into 3 stagesStage Size Duration

Recruitment < 0.13mm birth - Slow phase 0.16 – 3 mm 10 – 40 daysFast phase > 4 mm 8 - 10 days

(Lussier et al. 1987)

0 5 10 15 20 25 30 35 Calving Ovulation

DIM

16

14

12

10

8

6

4

2

0

Fol

licle

dia

met

er (

mm

)Resumption of Ovarian Activity

Atresia or ovulation IGF-1, IGFBP, E2, ….

Deviation Luteinizing Hormone (LH)

Emergence Follicle Stimulating Hormone (FSH)

0 5 10 15 20 25 30 35 Calving Ovulation

DIM

16

14

12

10

8

6

4

2

0

Fol

licle

dia

met

er (

mm

)Resumption of Ovarian Activity

33.8 days (1106 Lactations; Petersson et al. 2005)

27.4 days (>1200 Records; Royal et al. 2004)

28.7 ± 14.6 days (2503 Lactations, Lamming and Darwash 1998)

29 days Control line vs. 43 days Select (Lucy et al. 2001)

43 days First Estrus (1398 Lactations, Thatcher and Wilcox, 1973)

Resumption of Ovarian Activity

Reference Location DIM DOV1 ALL

Lopez et al. 2004 Wisconsin 70 28.5%

Cerri et al. 2004 California 65 25.7%

Moreira et al. 2001 Florida 63 23%

Opsomer et al. 2000 Belgium 50 21.2%49%

Lamming and Darwash 1998 England 10.9% 38%

Shrestha et al. 2004 Japan 24.1% 57%

Archbald et al. 1990 Florida 30 30%

McDougal and Compton 2005 NZ 20.9%

Thatcher and Wilcox 1973 Florida 60 25.9% (Estrus)

5 10 15 20 25 Days In Milk

16

14

12

10

8

6

4

2

0

Fol

licle

dia

met

er (

mm

)

(Wiltbank et al. 2002)

Anovulation

Follicular Growth to Deviation

Consecutive waves of follicle growth initiated by FSH

Insufficient LH to support deviation

Communication failure between ovary and hypothalamus

5 10 15 20 25 Days In Milk

16

14

12

10

8

6

4

2

0

Fol

licle

dia

met

er (

mm

)

(Wiltbank et al. 2002)

Anovulation

Follicles Larger than Ovulatory Size

LH release supports deviation

Elevated E2 concentration

Failure of ovulation

The presence of large follicles does not precludeNormal ovarian activity and function

Outline

• Resumption of Ovarian Activity

– Identification of at Risk cows

Objectives

• Determine prevalence of anovulation

• Assess consequences of anovulation

• Identify cow-level risk factors– herd-level risk factors

Observational Protocol

Milk Ketotest™

BCS

HH visit BCS, Lameness

Milk P4

Collect Reproduction and Culling Data

0 4 11 38 52 60

Record peripartumdisease

Data presented from 1341 cows

AnestrusBoth samples

<1ng/ml

Calving

Descriptive Data

Tiestall Freestall Herds Cows Herds Cows

Herd Size < 100 cows 9 404 3 178> 100 cows 1 65 5 694

 Milk Frequency

2 Times/day 9 404 4 2183 Times/day 1 65 4 654

 TAI First Service > 90 % 5 236 1 61

0 to 50% 5 233 7 775Rumensin

CRC 2 82 2 427 Premix 6 292 3 308Both 2 95 3 137

Study Population

• Enrolled 20 herds (lost 2)– Total calving 2645

– Culled prior to 52 DIM 277

– Total eligible 2368

– Two Milk Samples1 1575

– Met Inclusion criteria 1341 (56.7%)

• Herd specific inclusion ranged 33 – 90%

• Disease under-reported in cows not sampled

• No significant difference in parity distribution, first milk projection, days dry between included and excluded cows

• Excluded cows more likely culled (P < 0.001)

1 Excluded if milk sample protocol violated or use of hormones

Cow Level Prevalence of Anovulation

19.5% (95% CI 17.4 – 21.7%)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 180.0

0.1

0.2

0.3

0.4

0.5

Herd Number

An

estr

us (

%)

VWP 45-60 d

Calving

No Estrus Activity

Ovarian Activity ??

Impact of Anovulation

• 1 in 5 cows • Herd Repro Management

• Heat Detection • Timed Insemination protocols

Time to First Insemination

Herd ReproProgram Factor AI HR P 95% CI

Heat Anovular 80b 0.7 <0.0001 0.6 to 0.8Detection1 Cycling 72a Referent

Timed Anovular 78ab 0.67 0.19 0.1 to 1.2AI2 Cycling 76b Referent 

Multiparous 0.84 0.04 0.7 to 0.9Retained Placenta 0.75 <0.001 0.6 to 0.8

1 Insemination at Observed Estrus in >50% of herd (12 herds 79% of cows)2 Timed Insemination in > 90% of herd (6 herds, 21% of cows)

Probability of Pregnancy after First Insemination

Herd ReproProgram Factor FSCR OR P 95% CI

Heat Anovular 20.3b 0.6 0.007 0.4 to 0.6Detection1 Cycling 30.5a Referent

Timed Anovular 29.7ab 0.67 0.19 0.1 to 1.2AI2 Cycling 35.9a Referent 

Multiparous 0.73 0.02 0.6 to 0.9

1 Insemination at Observed Estrus in >50% of herd (12 herds 79% of cows)2 Timed Insemination in > 90% of herd (6 herds, 21% of cows)

Time to Pregnancy

0.00

0.25

0.50

0.75

1.00

Surv

ivor

Fu

nction

(Pro

port

ion n

ot

Pre

gna

nt)

0 50 100 150 200 250 300 350 400

Days in Milk

CyclingAnestrus

Kaplan-Meier survival estimates, by anest156

126

Time Adjusted HR 81 0.56123 0.74165 0.89

Adjusted HR = HR*TVCln(t)

Diagnosis of Anovulation

• Rectal Palpation1 (2 palpations 14-days apart)

• Sensitivity 65.4%• Specificity 68.6%• Positive Predictive value 31.9%

1 gold standard circulating progesterone

Diagnosis of Anovulation using Pedometry (HDR ~ 60%)

0

10

20

30

40

50

60

70

1 21 41 61 81 101

Mil

k (K

g/d

ay)

0

100

200

300

400

500

600

Ste

ps/

ho

ur

0

10

20

30

40

50

60

1 21 41 61 81 101

Mil

k (k

g/d

ay)

0

100

200

300

400

500

600

700

800

900

Ste

ps/

ho

ur

•Sensitivity 83.0%•Specificity 68.0%•Positive Predictive value 34.0%

Diagnosis of Anovulation Assumption 100 cows, True Prevalence of 20%

Test Detail Sensitivity Specificity Apparent Prevalence

(%)

Anovular and treated

(n)

Anovular and not treated

(n) Once 60 DIM1

0.41 0.75 28 8 12 Palpation

Twice 14d apart1

0.65 0.68 38 13 7

Once2

0.88 0.83 31 17 3

Ultrasound

+ no visible estrus3

0.86 0.88 27 17 3

Pedometry HDR ~ 60%4

0.83 0.68 42 17 3

1 Walsh et al. (Unpublished)2 Sprecher et al. 1989; Theriogenology3 McDougal and Rhodes, 1999; NZVJ (Apparently Anestrus cows)4 Core et al. (Unpublished)

Outline

• Resumption of Ovarian Activity

– Identification of at Risk cows

– Cow-level risk factors

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 180.0

0.1

0.2

0.3

0.4

0.5

Herd Number

An

estr

us (

%)

Univariable Risk Factor Analysis Factor Class n OR 95% CI

Twins 49 2.3** 1.27 to 4.22 Calving

Dystocia 113 1.8** 1.17 to 2.79 Retatined placenta 119 2.0*** 1.31 to 2.97 Displaced abomasum 42 2.3** 1.24 to 4.39 Disease Lame (back arch) 87 1.8* 1.36 to 2.90

BCS 2.75 (60 7 DIM) 529 1.5** 1.12 to 2.12 Week 1 100 271 1.7** 1.21 to 2.39 Week 2 100 265 1.5* 1.05 to 2.07

Milk BHBA

Week 2 200 132 1.6* 1.03 to 2.57 < 9500 522 0.98* 0.96 to 0.99 First

305ME 9500 819 1.0 0.98 to 1.01 Spring 255 Summer 277 Fall 417

Season

Winter 392

Controlling for fresh season (* P < 0.05; ** P < 0.01; *** P < 0.001)

Final Risk Factor Model Factor Class n OR 95% CI

Twins 49 2.15* 1.15 to 4.01 Calving

Dystocia 113 1.70* 1.07 to 2.72 Retained placenta 119 1.35 0.84 to 2.20 Displaced abomasum 42 2.4* 1.17 to 4.90 Disease Lame (back arch) 87 1.5 0.93 to 2.61

BCS 2.75 (60 7 DIM) 529 Week 1 100 271 1.49* 1.04 to 2.15 Week 2 100 265

Milk BHBA

Week 2 200 132 < 9500 522 0.98* 0.96 to 0.99 First

305ME 9500 819 1.0 0.99 to 1.02 Spring 255 1.12a 0.45 to 1.75 Summer 277 0.87ab 0.56 to 1.35 Fall 417 0.54*b 0.41 to 0.99

Season

Winter 392 Referent

(* P < 0.05; ** P < 0.01; *** P < 0.001)

Prevalence of anovulation by Parity

Data Table-3

1 2 30.0

0.1

0.2

0.3

Parity is an inconsistent risk factor for anovulation

Lameness• 238 Animals, 11% DOV

• Lameness (Median day of diagnosis = 15 DIM)

– 42% Moderately Lame– 17% Lame

• Relative to animals never classified as lame controlling for calving season, lactation, ketotsis*and Milk Production (305ME)*– Moderate Lameness 2.14 odds of DOV (95%CI = 0.7 , 6.14)

– Lame 3.5 increased odds of DOV (95% CI = 1.0 , 12.7)

Calving Lameness Score (1-5)

Milk P4

Garbarino et al. 2004

Lameness and Reproductive Performance

• 65 Cases, 130 Controls• Controlling for parity, calving season, and milk yeild

(305ME)– Non-lame cows 4.22 times more likely to conceive at first

service (95% CI 1.59 , 11.2)– Lame cows 2.63 times more likely to have an occurrence of

an ovarian cyst

• Using Survival analysis – Lame cows HR 0.43

(95% CI 0.28 , 0.66)

Melendez et al. 2003

Body condition Loss

• Lopez-Gatius et al. Theriogenology 2003

• 4529 cows from 11 studies

• Relative to BCS 2.5-3.5

• <2.5 at parturition + 6 DOPN

• >3.5 at parturition – 6 DOPN

• Relative to BCS change <0.5 units between parturition and first AI

• Loss >1 +10.6 DOPN

• Not significant in all studies

• Ruegg et al. 1995

• Domecq et al. 1999

Milk ProductionStudy Milk Measure Delayed OvulationOpsomer et al. 2000 100d & 305d FCM ns

Shrestha et al. 2004 305d FCM ns

Santos et al. 2004 Proj 305 ME 0.21(0.05 to 0.98) high vs. Med

Time to PregnancyGröhn and Rajala-Schultz

2000 60d Milk HR 0.92 (highest vs. lowest)

Outline

• Resumption of Ovarian Activity

– Identification of at Risk cows

– Cow-level risk factors

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 180.0

0.1

0.2

0.3

0.4

0.5

Herd Number

An

estr

us (

%)

Cow Level Prevalence of Subclinical Ketosis Week 1

26.2% (95% CI 23.5 to 28.9 %)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 180.00

0.25

0.50

0.75

1.00

Herd Number

Su

bc

lin

ica

l K

eto

sis

(%)

Energy Balance and DOV• 54 Multiparous HF cows calculated energy

balance

Item ER LR NRNumber 25 (46%) 14 (26%) 15

(28%)

4% FCM (kg/d) 33.4 31.7 28.5

DMI (kg/d) 18.8 17.7 15.2

Day to Ovulation 21.9 43.1

Days Open 133 88 200

Calving7 14 21 28 35 42 49 56 63

Progesterone Profile ER LR NR

Staples et al. 1990

Estimating Energy Status• Significant correlation

between ketone body concentration and CLA (Reist et al. 2000)

• Milk Acetone week 3-6 not associated with FSCR (Plym-Forshell, 1991)

• Increased DOPN, Increased culling risk (Cook et al. 2000)

• 1400 mol/ml HBA cutpoint used for disease status

Impact of subclinical ketosis on the probability of pregnancy at first service and time to pregnancy

Objectives• Is SCK early in lactation associated with the

probability of pregnancy at first insemination?• Which week postpartum has the most impact?• Does the duration of SCK impact probability of

pregnancy at first insemination or time to pregnancy?

Impact of subclinical ketosis on the probability of

pregnancy at first service and time to pregnancy

Serum SampleStore samples and analyze for

HBA

BCS

Observe for estrus and breed

PD

-3 0 1 2 3 6 9

Calving

BCS

25 Herds (25-160 cows)

1010 cows

Exclusion criteria

806 records for analysis

Rumensin CRC study 1995-1996 (Duffield et al. 1999)

Distribution of serum BHBA

0

50

100

150

200

250

300

350

500 800 1000 1100 1300 1500 1700 1900 1901

BHBA Concentration (Week 1 vs. Week2)

Nu

mb

er o

f C

ow

s

16% week 1 (132/806 cows)

19% Week 2 (152/806 cows)

Mean Serum BHBA Sorted by Pregnancy

Diagnosis to First Insemination

-3 -2 -1 0 1 2 3 4 5 6 7 8 9600

650

700

750

800

850

900OpenPregnant

Week Relative to Calving

LS

Mea

n Se

rum

BH

BA

Investigation of Cutpoints

Week BHBA

cutpoint n

% Pregnant

below cutpoint

n

% Pregnant

above cutpoint

OR P-

value

1000 508 37.9 288 29.2 0.73 0.04 1200 606 36.6 190 28.9 0.78 0.16 1 1400 670 36.1 126 27.7 0.75 0.21

1200 601 37.5 206 28.9 0.87 0.42 1400 651 37.0 151 22.5 0.60 0.01 2 1600 685 37.9 117 18.8 0.48 0.002

Impact of Subclinical Ketosis in the Second Week Postpartum on the Probability of

Pregnancy at First Insemination

0.1

.2.3

.4

Pro

ba

bili

ty o

f P

reg

na

ncy

0 2000 4000 6000 8000

Week 2 serum BHBA concentration (mmol/L)

Effect of Prolonged Elevation of Serum BHBA on the Probability of Pregnancy at First Insemination

15

20

25

30

35

40

45

0 1 >1

Number of Weeks Above BHBA Cutpoint

Pro

bab

ility

of P

regn

anc

y (%

)

OR = 0.83P = 0.2 OR = 0.47

P = 0.003

Impact of duration of subclinical ketosis on time to pregnancy

0.00

0.25

0.50

0.75

1.00

Sur

viva

l Fun

ctio

n (

Pro

port

ion

Not

Pre

gnan

t)

0 100 200 300 400

Days in Milk

Not Ketotic

Ketotic week 1 or week 2

Ketotic both week 1 and 2

Time Adjusted HR 81 0.62 0.63123 0.75 0.84165 0.85 1.02

Adjusted HR = HR*TVCln(t)

Median time to Pregnancy

108124130

Cow-level Summary

• Diagnosis is problematic

• Calving history / periparturient disease

• Subclinical ketosis

Dry Period Length

• >77days vs. <63 days 2.9 times more likely to experience DOV(Opsomer et al. 2000)

• DD associated with increase risk of longer DOPN (Moss et al.

2002)

(Gümen et al. 2005)

Milking Frequency

• 3X vs 2X majority of studies show no difference (Weiss et al. 2004; Barnes et al. 1990; Amos et al. 1985*)

• 3X vs 2X associated with 6d increase DOPN (Smith et al. 2002)

• 3X vs. 6X for 3 weeks increased DOPN (Bar-Peled et al. 1995)

Herd-Season Anovulation Prevalence

• 34 herd-seasons from 18 herds (Fall vs. Other)

• Linear regression of herd-level prevalence

• Relative to Tie-Stall barns the prevalence of anestrus

• ↓ 7.2% in 3-Row Freestalls (P = 0.1)

• ↓ 11.0 % in 2-Row Freestalls (P = 0.007)

• ↑ 2.1% for every 10% ↑in herd-season prevalence of SCK

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 180.0

0.1

0.2

0.3

0.4

0.5

Herd Number

An

estr

us (

%)

Herd-Season Anovulation Prevalence

• Things to Consider– Stocking density– Number of ration or group changes– Dry period length

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 180.0

0.1

0.2

0.3

0.4

0.5

Herd Number

An

estr

us (

%)

Questions ?

  

Acknowledgement

 

AdvisorsDrs. Leblanc, Leslie, Duffield, Kelton and Walton

VeterinariansAlmonte, Bay of Quinte Veterinary Services, Embrun, Ferguson, Grenville-Dundas, Kirkton, Linwood, Listowel, Navan, New Hamburg,

Tavistock

AABP ResearchAssistantship