Jeffrey S. Stevenson, Ph.D.

Department of Animal Sciences

and Industry

Getting Cows PregnantGetting Cows Pregnant

Ontario Association ofOntario Association ofBovine PractitionersBovine Practitioners

Reproductive SymposiumReproductive Symposium

Estrus-Detection Estrus-Detection ProgramsPrograms

No hormonal No hormonal interventionintervention

Insemination

Rebreeding or

pregnancy diagnosis

End of VWP

Heat detection

only

First Service OptionsFirst Service Options

Pregnancy RatesPregnancy Rates

0

10

20

30

40

50

%

Weighted average Unweighted average

Detected estrus Ovsynch

1,190 cows 9 studies each

1,155 cows

Adapted from Rabiee et al. (2005)

NS difference

PGFPGF22 Programs Programs

Detection of EstrusDetection of Estrus

Insemination

Rebreeding or

pregnancy diagnosis

End of VWP

Heat detection

PGF

First Service OptionsFirst Service Options

Heat detection

PGF

Heat detection

PGF

Insemination

Insemination

0 wk

2 wk

4 wk

Insemination

Rebreeding or

pregnancy diagnosis

Ovsynch

GnRHTAIPGF

M M W Th

GnRH

End of VWP

Heat detection

PGF

First Service OptionsFirst Service Options

Cows not detected in heat by ??? days in milk

Pregnancy RatesPregnancy Rates

0

10

20

30

40

50

%

Weighted average Unweighted average

PGF + detected estrus Ovsynch

2,234 cows 16 studies each

2,209cows

Adapted from Rabiee et al. (2005)

NS difference

GnRHGnRHPGFPGF22

ProgramsPrograms ++ Detection of EstrusDetection of Estrus

Select Synch

PGF

M M

GnRH

First Service OptionsFirst Service Options

Rebreeding or

pregnancy diagnosis

InseminationHeat detection

Ovsynch

GnRHTAIPGF

M M W Th

GnRHCows not detected in heat by ??? days in milk

End of VWP

Pregnancy RatesPregnancy Rates

0

10

20

30

40

50

%

Weighted average Unweighted average

Select Synch + detected estrus Ovsynch

764 cows 5 studies each

770 cows

Adapted from Rabiee et al. (2005)

NS difference

Timed AI Programs:Timed AI Programs:OvsynchOvsynch

End of VWP

GnRHTAIPGF

M M W Th

Ovsynch

GnRH

First Service OptionsFirst Service Options

48 hr

32

4145

4137

0

10

20

30

40

50

0 8 16 24 32

Hours between the Second GnRH Injection and TAI

Conception rate

Calving rate

Poly. (Calving rate)

Poly. (Conceptionrate)

%

Pursley et al. (1998)

Day of Estrous Cycle at OnsetDay of Estrous Cycle at Onsetof the Ovsynch Protocolof the Ovsynch Protocol

28

41 4034 36

0

10

20

30

40

50

1-4 5-8 9-12 13-16 17-21

Days of Cycle

Con

cept

ion

rate

s, %

Vasconcelos et al. (1999)

Timed AI Programs:Timed AI Programs:Presynchronized Presynchronized Cycles + OvsynchCycles + Ovsynch

Injection Schedule forInjection Schedule forPresynch + Ovsynch ProgramPresynch + Ovsynch Program

Week 1

M

T W Th F S S

2

M T W Th F S S

3

M T W Th F S S

4

M T W Th F S S

5

M T W Th F S S

6

M T W Th F S S

PGFPGF

PGFPGF

PGFPGF

GnRHGnRH

TAITAIGnRHGnRH

12 days

Estrus

Estrus

Rebreeding or pregnancy diagnosis

End of VWP

GnRH

AIPGF

M M W Th

12-14 days

GnRH

OvsynchPresynch

PGF

14 days

First First ServiceService Options Options

PGF

Week 1

M

T W Th F S S

2

M T W Th F S S

3

M T W Th F S S

4

M T W Th F S S

5

M T W Th F S S

6

M T W Th F S S

PGFPGF

PGFPGF

PGFPGF GnRHGnRH TAITAI

GnRHGnRH

29 3643 48

0

10

20

30

40

50

60

Florida Kansas

Ovsynch Presynch+Ovsynch

n = 262 n = 264

n = 272 n = 278

Presynch + Ovsynch ProgramPresynch + Ovsynch Program

Moreira et al. (2001)

El-Zarkouny et al. (2004)

12 days

Pregnancy RatesPregnancy Rates

0

10

20

30

40

50

%

Weighted average Unweighted average

Presynchronized Cycles + Ovsynch Ovsynch

971 cows 7 studies each

982 cows

2 = 21.084; P < 0.001

W W M M

End of VWP

PGF

7 d

GnRH

OvsynchPresynch

PGF PGF

14 days

GnRH+TAI

TAIGnRH

GnRH+TAI

W Th

Cosynch 48

Cosynch 72

Ovsynch

Portaluppi and Stevenson (2006)

24 hr48 hr

72 hr4

8 h

r

12 days

Kansas Presynch-Ovsynch StudyKansas Presynch-Ovsynch Study

22.8%

23.5%

(n = 665)

31.4%

F F T T

End of VWP

PGF

11 days

GnRH

OvsynchPresynch

PGF PGF

14 days

GnRH+TAI

TAIGnRH

GnRH+TAI

Th F

Cosynch 48

Cosynch 72

Ovsynch 56

Brusveen et al. (2006)

16 hr

48

hr

72 hr

56 hr7 d

Wisconsin Presynch-Ovsynch StudyWisconsin Presynch-Ovsynch Study

44.8%

36.2%

24.6%

(n = 343)

Timed AI Programs:Timed AI Programs: + Progesterone + Progesterone

Pregnancy RatesPregnancy Rates

0

10

20

30

40

50

%

Weighted average Unweighted average

Ovsynch

Ovsynch + CIDR

730 cows 3 studies each

718 cows

NS difference

CIDR

Ovsynch + CIDROvsynch + CIDR

PGF

GnRH

GnRH

PGF

TAI

Ovsynch

Ovsynch+C GnRH

TAIGnRH

50% 40%

38% 33%

Conception rates

Day 28 Day 56

–7 0 +48 +64Days Hours

Stevenson et al. (2006)

n = 634 cows

Effect of Location and Cyclicity on Effect of Location and Cyclicity on Pregnancy Rates at Day 28Pregnancy Rates at Day 28

0

20

40

60

80

100

%

IL KS MI MO OH WI

Ovsynch OVS+CIDR Cycling

Treatment × herd interactionStevenson et al. (2006)

Conception Rates at 56 d after TAI Conception Rates at 56 d after TAI based on Cycling Status and Serum based on Cycling Status and Serum

P4 at PGFP4 at PGF

Pretreatment cycling status

Serum P4

before PGF2

Luteal status

before PGF2 OVSOVS + CIDR

NoncyclingHighLow

Active induced CL4

No induced CL4

39 (58)17 (38)

34 (47)33 (41)

CyclingHighLow

Active CL Early luteolysis

39 (178)19 (47)

43 (179)38 (46)

Treatment

Stevenson et al. (2006)

Pregnancy RatesPregnancy Rates

0

10

20

30

40

50

%

Weighted average Unweighted average

Presynch + Ovsynch

Presynch + Ovsynch + CIDR

1,599cows 4 studies each

1,609cows

NS difference

““Cherry Picking”Cherry Picking”

012345678

TAI Notpreg.

Preg.

Pro

gest

eron

e, n

g/m

L

Presynch + Ovsynch

Presynch + Ovsynch + CIDR

Melendez et al. (In press)

22.7

31.2

0

10

20

30

40

50

%

Presynch + Ovsynch

Presynch + Ovsynch + CIDR

589 cows

586 cows

d 14d 0

Costs per PregnancyCosts per Pregnancy

Item

Breeding Program

Detected estrus Ovsynch

Presynch + OVS

Annual cost, $

Unadj. cost/pregnancy, $

No. of reproductive culls

Average days open

Cost/day open beyond 85 d

Adjusted cost/pregnancy, $

11,801

55.40

37

162

3.16

298.35

17,221

73.66

16

122

1.16

115.39

18,507

78.59

15

116

1.02

110.49

Adapted from Nebel et al. (2003)

Thank you!

Department of Animal Sciences

and Industry

Ontario Association of Ontario Association of Bovine Practitioners Bovine Practitioners Reproductive SymposiumReproductive Symposium