How to Get Cows Pregnant for How to Get Cows Pregnant for the Purebred and Commercial the Purebred and Commercial Sectors of the Beef Industry – Sectors of the Beef Industry –

Using GnRH and CIDRsUsing GnRH and CIDRs

Cliff LambCliff Lamb

University of MinnesotaUniversity of Minnesota

Beef Improvement FederationBeef Improvement Federation

July 2005July 2005

Natural Service

vs.

Estrous Synchronization and AI

Protocol 30 hd 100hd 300hd

Natural Service 58 35 35

MGA-PGF 62 41 37

MGA Select 66 45 41

MGA Select – TAI 70 51 48

Select Synch 68 46 41

CO-Synch 70 51 47

PGF-CIDR 73 51 47

CO-Synch+CIDR 80 61 55

Select Synch+CIDR 76 55 51

Cost ($) per Pregnancy of Various Estrous Synchronization Protocols

Herd size

(Johnson and Jones, 2004)

Advantages of Natural Advantages of Natural Service and Artificial Service and Artificial

InseminationInsemination

Genetic Improvement

Proven sires

Shorten breeding season

Shorten calving season

Uniform calf crop

Induce cyclicity

Cost

Hassle factorLaborTime

Good bulls at reasonable price

Natural Service Artificial Insemination

0

20

40

60

80

100

1 2 3 4 5 6 7 8 9

Body condition score at calving

Days

to fi

rst

est

rus

HighAdequateLow

(Short et al., 1988)

Effect of Postcalving Feed on Postpartum Estrus

Postcalving feed

Effect of Body Condition on Cyclicity

49

59

71

80

25

42

0

20

40

60

80

100

<3.5 4.0 4.5 5.0 5.5 >6

%

Body condition score

(Stevenson et al., 2004)

Effect of Parity and Body Condition on Ovulation Rates

42

48

25

34

43

53

10

17

0

10

20

30

40

50

60

<4 4.5 5.0 >5.5

%

Body condition score

(Stevenson et al., 2004)

Effect of Days Postpartum on Cyclicity

44 45

55

62

70

62

9

25

0

20

40

60

80

<30 31-40 41-50 51-60 61-70 71-80 81-90 >90

%

Body condition score

(Stevenson et al., 2004)

Estrous Synchronization Protocols

Two shot PGF

7-11 Synch Select Synch

Ov-synch

CO-synch

MGA/PGF

MGA Select

CIDR/PGF

CO-synch+CIDR Heat Synch

Hybrid Synch

Hybrid Synch+CIDR

One shot PGF

PresynchResynch

BEEF COW PROTOCOLS

Select Synch

HEAT DETECTION

FIXED-TIME AI (TAI)

MGA® Select

7 13

PGGnRH

0 4

Heat detect & AI

Select Synch + CIDR®

7 13

CIDR®

0

GnRH

0

GnRH PG

Heat detect & AI

MGAPG

0 14

GnRH

26

GnRH

26 33 39

Heat detect & AI

GnRH

0 4 7

PG

Heat detect & AI

10

GnRH

AI

7

PGGnRH

0

GnRH

0

Heat detect & AI

10

GnRH

AICIDR®

Select Synch & TAI

Select Synch + CIDR® & TAI

7

PGGnRH

0

GnRH

0 10

GnRH

AICIDR®

CO-Synch + CIDR®

MGA® Select

MGAPG

0 14

GnRH

26

GnRH

26 33 36

GnRH

AI

HighMediumMGA® Select

(TAI at 72 hr after PG with GnRH at TAI)

• The times listed for “Fixed-time AI” should be considered as the approximate average time of insemination. This should be based on the number of cows to inseminate, labor, and facilities.

Medium/HighLowSelect SynchLABORCOSTHEAT DETECTION

COMPARISON OF PROTOCOLS FOR BEEF COWS

Medium/HighMediumMGA® SelectMediumHighSelect Synch + CIDR®

Medium/HighLowSelect Synch (TAI non-responders 72-84 hr after PG)

HEAT DETECT & TAI

Medium/HighMediumMGA® Select (TAI non-responders 72-84 hr after PG)

MediumHighSelect Synch + CIDR®

(TAI non-responders 72-84 hr after PG)

MediumHighCO-Synch + CIDR®

(TAI at 66 hr after PG with GnRH at TAI)

FIXED-TIME AI (TAI)

HighMediumMGA® Select

(TAI at 72 hr after PG with GnRH at TAI)

• The times listed for “Fixed-time AI” should be considered as the approximate average time of insemination. This should be based on the number of cows to inseminate, labor, and facilities.

Medium/HighLowSelect SynchLABORCOSTHEAT DETECTION

COMPARISON OF PROTOCOLS FOR BEEF COWS

Medium/HighMediumMGA® SelectMediumHighSelect Synch + CIDR®

Medium/HighLowSelect Synch (TAI non-responders 72-84 hr after PG)

HEAT DETECT & TAI

Medium/HighMediumMGA® Select (TAI non-responders 72-84 hr after PG)

MediumHighSelect Synch + CIDR®

(TAI non-responders 72-84 hr after PG)

MediumHighCO-Synch + CIDR®

(TAI at 66 hr after PG with GnRH at TAI)

FIXED-TIME AI (TAI)

Heat detect and AI day 4 to 10 and TAI all non-responders 72 – 84 hr after PG with GnRH at TAI.

Heat detect and AI day 7 to 10 and TAI all non-responders 72 - 84 hr after PG with GnRH at TAI.

Perform TAI at 66 hr after PG with GnRH at TAI.

Perform TAI at 72 hr after PG with GnRH at TAI.

GnRH

PG

Cystorelin®, Factrel®, Fertagyl®, OvaCyst®

Estrumate®, In-Synch®, Lutalyse®, ProstaMate®D.J. Schafer and D.J. Patterson Division of Animal Sciences - University of Missouri – Columbia These protocols are recommended by the North Central Region Bovine Reproduction Task Force.

HEAT DETECT & TIME AI (TAI)

… 12 d … … 7 d …

MGA® Select & TAI

MGAPG

0 14

GnRH

26

GnRH

26 33

Heat detect & AI

GnRH

36

AI

GnRH

36

AI

Heat detect and AI day 33 to 36 and TAI all non-responders 72 - 84 hr after PG with GnRH at TAI.

… 12 d … … 7 d … .. 72 - 84 hr ..

.. 72 - 84 hr ..

.. 72 - 84 hr ..

… 12 d … … 7 d … .. 72 hr ..

.. 66 hr ..

treatment day

treatment day

treatment day

treatment day

treatment daytreatment day

treatment day

treatment day

BEEF HEIFER PROTOCOLS

1 Shot PG

HEAT DETECTION HEAT DETECT & TIME AI (TAI)

FIXED-TIME AI (TAI)

CIDR®-PG

MGA®-PG

PG

Heat detect & AI

00 77 1313

CIDR®

PG

Heat detect & AI

MGA

0 14

PG

33 3939

Heat detect & AI

MGA®-PG & TAI

MGA

0 14

PG

33

Heat detect & AI

GnRH

36

AI

Select Synch + CIDR® & TAI

GnRH

0

GnRH

0 7

PG

7

PG

9

GnRH

AI

9

GnRH

AICIDR®

CO-Synch + CIDR®

MGA®-PG

MGA

0 14

PG

33

PG

33 36

GnRH

AI

36

GnRH

AI

GnRH

00 7

PG

Heat detect & AI

10

GnRH

AI

10

GnRH

AICIDR®

MediumMediumMGA®-PG

(TAI at 72 hr after PG with GnRH at TAI)

• The times listed for “Fixed-time AI” should be considered as the approximate average time of insemination. This should be based on the number of heifers to inseminate, labor, and facilities.

HighLow1 Shot PGLABORCOSTHEAT DETECTION

COMPARISON OF PROTOCOLS FOR BEEF HEIFERS

Low/MediumLowMGA®-PGMediumMediumCIDR®-PG

HEAT DETECT & TAI

MediumMediumMGA®-PG (TAI non-responders 72-84 hr after PG)

MediumHighSelect Synch + CIDR®

(TAI non-responders 72-84 hr after PG)

MediumHighCO-Synch + CIDR®

(TAI at 54 hr after PG with GnRH at TAI)

FIXED-TIME AI (TAI)

MediumMediumMGA®-PG

(TAI at 72 hr after PG with GnRH at TAI)

• The times listed for “Fixed-time AI” should be considered as the approximate average time of insemination. This should be based on the number of heifers to inseminate, labor, and facilities.

HighLow1 Shot PGLABORCOSTHEAT DETECTION

COMPARISON OF PROTOCOLS FOR BEEF HEIFERS

Low/MediumLowMGA®-PGMediumMediumCIDR®-PG

HEAT DETECT & TAI

MediumMediumMGA®-PG (TAI non-responders 72-84 hr after PG)

MediumHighSelect Synch + CIDR®

(TAI non-responders 72-84 hr after PG)

MediumHighCO-Synch + CIDR®

(TAI at 54 hr after PG with GnRH at TAI)

FIXED-TIME AI (TAI)

Heat detect and AI day 7 to 10 and TAI all non-responders 72 - 84 hr after PG with GnRH at TAI.

Heat detect and AI day 33 to 36 and TAI all non-responders 72 - 84 hrs after PG with GnRH at TAI.

Perform TAI at 54 hr after PG with GnRH at TAI.

Perform TAI at 72 hr after PG with GnRH at TAI.

-5 6

GnRH

PG

Cystorelin®, Factrel®, Fertagyl®, OvaCyst®

Estrumate®, In-Synch®, Lutalyse®, ProstaMate®D.J. Schafer and D.J. Patterson Division of Animal Sciences - University of Missouri – Columbia These protocols are recommended by the North Central Region Bovine Reproduction Task Force.

0

… 19 d …

… 19 d … .. 72 hr ..

.. 54 hr ..

.. 72 - 84 hr ..

.. 72 - 84 hr ..

… 19 d …

treatment day

treatment day

treatment day

treatment day

treatment day

treatment day

treatment day

CIDR and GnRH Based Protocols

Concentrations of Progesterone in Concentrations of Progesterone in Ovariectomised Cows Produced by CIDR Ovariectomised Cows Produced by CIDR

Containing 1.9g and 1.38g Progesterone Over a Containing 1.9g and 1.38g Progesterone Over a 20 Day Treatment20 Day Treatment

( = CIDR1900 Cattle insert, = CIDR1380 Cattle insert, N = 10, error bars = SEM)

0

1

2

3

4

5

6

0 2 4 6 8 10 12 14 16 18 20 22Time (days)

Pla

sma

prog

este

rone

co

ncen

trat

ion

(ng/

mL

)

CIDR Protocols in HeifersCIDR Protocols in Heifers

PGFTAI &GnRH

Detect estrus & AI

PGFGnRHTAI &GnRH

CIDRCIDR-PG & TAI

PGFTAI &GnRH

Detect estrus & AI

GnRH

PGFTAI &GnRH

-18 to -16 -7 0 60 84

B B

Days relative to PGFHours relative to PGF

CIDR

CIDR

CIDR

Select Synch+CIDR & TAI

CO-Synch+CIDR

CIDR-PG+TAI

Effect of Location on Pregnancy Rates

61

38

74

5358 57 55

39

485353 54

0

20

40

60

80

IL-1 IL-2 KS-1 KS-2 MN-1 MN-2 MT-1 MT-2 MT-3 ND OH-1 OH-2

Locations

%

First Service Pregnancy Rates

53.149.1

54.557.3

0

20

40

60

80

CIDR-PG & TAI Select Synch+CIDR&TAI

CO-Synch+CIDR CIDR-PG+TAI

%

Treatments

n = 282/517

n = 289/504

n = 258/525

n = 282/531

Pregnancy Rates after Estrus Detection Alone vs TAI

49.1

9.910.5

53.144.6 46.8

0

10

20

30

40

50

60

70

CIDR-PG & TAI Select Synch+CIDR&TAI

CO-Synch+CIDR CIDR-PG+TAI

%

Treatment

54.557.3

53.149.1

P = 0.221

PGFTAI &GnRH

Detect estrus & AI

CIDR

PGFTAI &GnRH

Detect estrus & AI

GnRH

-7 0 60 84

Days relative to PGFHours relative to PGF

CIDR

CIDR-PG & TAI

Select Synch+CIDR & TAI

Distribution of estrus as a percentage of all heifers treated

0 1

10

23 23

12

4

0

27

0 0

9

28

22

11

3

0

27

0

10

20

30

40

50

0-12 12-24 24-36 36-48 48-60 60-72 72-84 >84 No estrus

%

CIDR-PG and TAI

Select Synch + CIDR and TAI

Hours after PGF

58%

61%

Hours from PGF to Estrus

50.0 49.8

40.0

45.0

50.0

55.0

60.0

CIDR-PG and TAI Select Synch +CIDR and TAI

Hours

fro

m P

GF

Treatments

CIDR Protocols in CowsCIDR Protocols in Cows

PGFTAI &GnRH

PGF

GnRH

GnRHTAI &GnRH

-7 0 48

Days relative to PGF Hours relative to PGF

CO-Synch

CO-Synch+CIDRCIDR

CO-synch vs. CO-synch+CIDR

(Lamb et al., 2001)

First Service Pregnancy Rates

48

59

20

30

40

50

60

70

CO-Synch COSynch+CIDR

%

Treatments

30

41

59

31

50

85

0

20

40

60

80

100

<4.5 5 >5.5

Pre

gnancy

rate

s, %

CO-SynchCO-Synch+CIDR

Effect of BCS on Pregnancy Rates

(Lamb et al., 2001)

Body condition score

PGFTAI &GnRH

Detect estrus & AI

PGFTAI &GnRH

PGF

PGFTAI &GnRH

Detect estrus & AI

PGFTAI &GnRH

Detect estrus & AI

GnRH

GnRH

GnRH

GnRH

TAI &GnRH

-18 to -16 -7 0 60 84

B BDays relative to PGF Hours relative to PGF

CIDR-PG & TAI

CO-Synch

CO-Synch+CIDR

Select Synch & TAI

Select Synch+CIDR & TAI

CIDR

CIDR

CIDR

Effect of Location on Pregnancy Rates

64

46

5348

3942

57 5852

55

47

5453

67

0

20

40

60

80

IL-1 IL-2 IN KS-1 KS-2 MN-1 MN-2 MN-3 MT OH-1 OH-2 OH-3 OH-4 TN

%

Locations

First Service Pregnancy Rates

54 53

5853

43

20

30

40

50

60

70

CIDR-PG & TAI CO-Synch COSynch+CIDR Select Synch &TAI

SelectSync+CIDR & TAI

%

Treatments

n = 266/506

n = 238/548

n = 269/507

n = 289/498

P < 0.05

n = 290/539

x

b

xx

x

Pregnancy Rates after Estrus Detection Alone vs TAI

41

14 1210

485439 43

0

10

20

30

40

50

60

70

CIDR-PG & TAI CO-Synch COSynch+CIDR Select Synch &TAI

SelectSync+CIDR and

TAI

%

TreatmentP < 0.05

a ba,bcb

53

43

54 5358

Effect of Days Postpartum on Pregnancy Rates

5255

52

46

54

20

30

40

50

60

70

<50 51-60 61-70 71-80 >80

%

Days postpartum

PGFTAI &GnRH

Detect estrus & AI

PGFTAI &GnRH

Detect estrus & AI

PGFTAI &GnRH

Detect estrus & AI

GnRH

GnRH

-7 0 60 84

Days relative to PGF Hours relative to PGF

CIDR

CIDR

Characteristics of Estrus

CIDR-PG & TAI

Select Synch & TAI

Select Synch+CIDR & TAI

Distribution of estrus

01

4

1920

12

6

2

36

12

3

12

21

14

4

2

40

0 1

4

16

25

16

6

2

31

0

10

20

30

40

0-12 12-24 24-36 36-48 48-60 60-72 72-84 >84 No estrus

%

PGF/CIDRSelect Synch & TAISelect Synch+CIDR & TAI

Hours after PGF

52%47%57%

Hours from PGF to Estrus and AI

51.5

53.452.8

64.562.663.1

30

40

50

60

70

PGF-CIDR & TAI Select Synch & TAI Select Synch+CIDR & TAI

Treatments

Tim

e,

h

PGF to estrus PGF to AI

n = 325 n = 309 n = 345

Calving Distribution after Synchronization of Estrous

0

1

2

3

4

5

6

7

<267 281 296 311 326 341 >355

Days after PG (Day 0)

% c

alv

ing

Treatment Gestation length AI calves Clean-up bulls

PGF-CIDR &TAI 281.2 0.54 0.51

CO-Synch 281.8 0.49 0.50

CO-Synch+CIDR 282.2 0.50 0.57

Select Synch & TAI 281.7 0.57 0.47

Select Synch+CIDR & TAI 281.9 0.53 0.54

Overall 281.7 0.53 0.52

Overall births 994 841 635

Calving Characteristics

Gender ratio

Recommendations (for optimum PR) - Recommendations (for optimum PR) - Estrus DetectionEstrus Detection

PGFTAI &GnRH

Detect estrus & AI

GnRH

-7 0 72- 84

Days relative to PGF Hours relative to PGF

Select Synch+CIDR & TAI

CIDR

Cows and HeifersCows and Heifers

Recommendations (for optimum PR) - Recommendations (for optimum PR) - Timed AITimed AI

-7 0 60 - 66

Days relative to PGF Hours relative to PGF

CO-Synch+CIDR

HeifersHeifers

-7 0 54 - 60

PGFGnRHTAI &GnRH

CIDR

PGFGnRHTAI &GnRH

CIDR

CowsCows

BEEF COW PROTOCOLS

Select Synch

HEAT DETECTION

FIXED-TIME AI (TAI)

MGA® Select

7 13

PGGnRH

0 4

Heat detect & AI

Select Synch + CIDR®

7 13

CIDR®

0

GnRH

0

GnRH PG

Heat detect & AI

MGAPG

0 14

GnRH

26

GnRH

26 33 39

Heat detect & AI

GnRH

0 4 7

PG

Heat detect & AI

10

GnRH

AI

7

PGGnRH

0

GnRH

0

Heat detect & AI

10

GnRH

AICIDR®

Select Synch & TAI

Select Synch + CIDR® & TAI

7

PGGnRH

0

GnRH

0 10

GnRH

AICIDR®

CO-Synch + CIDR®

MGA® Select

MGAPG

0 14

GnRH

26

GnRH

26 33 36

GnRH

AI

HighMediumMGA® Select

(TAI at 72 hr after PG with GnRH at TAI)

• The times listed for “Fixed-time AI” should be considered as the approximate average time of insemination. This should be based on the number of cows to inseminate, labor, and facilities.

Medium/HighLowSelect SynchLABORCOSTHEAT DETECTION

COMPARISON OF PROTOCOLS FOR BEEF COWS

Medium/HighMediumMGA® SelectMediumHighSelect Synch + CIDR®

Medium/HighLowSelect Synch (TAI non-responders 72-84 hr after PG)

HEAT DETECT & TAI

Medium/HighMediumMGA® Select (TAI non-responders 72-84 hr after PG)

MediumHighSelect Synch + CIDR®

(TAI non-responders 72-84 hr after PG)

MediumHighCO-Synch + CIDR®

(TAI at 66 hr after PG with GnRH at TAI)

FIXED-TIME AI (TAI)

HighMediumMGA® Select

(TAI at 72 hr after PG with GnRH at TAI)

• The times listed for “Fixed-time AI” should be considered as the approximate average time of insemination. This should be based on the number of cows to inseminate, labor, and facilities.

Medium/HighLowSelect SynchLABORCOSTHEAT DETECTION

COMPARISON OF PROTOCOLS FOR BEEF COWS

Medium/HighMediumMGA® SelectMediumHighSelect Synch + CIDR®

Medium/HighLowSelect Synch (TAI non-responders 72-84 hr after PG)

HEAT DETECT & TAI

Medium/HighMediumMGA® Select (TAI non-responders 72-84 hr after PG)

MediumHighSelect Synch + CIDR®

(TAI non-responders 72-84 hr after PG)

MediumHighCO-Synch + CIDR®

(TAI at 66 hr after PG with GnRH at TAI)

FIXED-TIME AI (TAI)

Heat detect and AI day 4 to 10 and TAI all non-responders 72 – 84 hr after PG with GnRH at TAI.

Heat detect and AI day 7 to 10 and TAI all non-responders 72 - 84 hr after PG with GnRH at TAI.

Perform TAI at 66 hr after PG with GnRH at TAI.

Perform TAI at 72 hr after PG with GnRH at TAI.

GnRH

PG

Cystorelin®, Factrel®, Fertagyl®, OvaCyst®

Estrumate®, In-Synch®, Lutalyse®, ProstaMate®D.J. Schafer and D.J. Patterson Division of Animal Sciences - University of Missouri – Columbia These protocols are recommended by the North Central Region Bovine Reproduction Task Force.

HEAT DETECT & TIME AI (TAI)

… 12 d … … 7 d …

MGA® Select & TAI

MGAPG

0 14

GnRH

26

GnRH

26 33

Heat detect & AI

GnRH

36

AI

GnRH

36

AI

Heat detect and AI day 33 to 36 and TAI all non-responders 72 - 84 hr after PG with GnRH at TAI.

… 12 d … … 7 d … .. 72 - 84 hr ..

.. 72 - 84 hr ..

.. 72 - 84 hr ..

… 12 d … … 7 d … .. 72 hr ..

.. 66 hr ..

treatment day

treatment day

treatment day

treatment day

treatment daytreatment day

treatment day

treatment day

BEEF HEIFER PROTOCOLS

1 Shot PG

HEAT DETECTION HEAT DETECT & TIME AI (TAI)

FIXED-TIME AI (TAI)

CIDR®-PG

MGA®-PG

PG

Heat detect & AI

00 77 1313

CIDR®

PG

Heat detect & AI

MGA

0 14

PG

33 3939

Heat detect & AI

MGA®-PG & TAI

MGA

0 14

PG

33

Heat detect & AI

GnRH

36

AI

Select Synch + CIDR® & TAI

GnRH

0

GnRH

0 7

PG

7

PG

9

GnRH

AI

9

GnRH

AICIDR®

CO-Synch + CIDR®

MGA®-PG

MGA

0 14

PG

33

PG

33 36

GnRH

AI

36

GnRH

AI

GnRH

00 7

PG

Heat detect & AI

10

GnRH

AI

10

GnRH

AICIDR®

MediumMediumMGA®-PG

(TAI at 72 hr after PG with GnRH at TAI)

• The times listed for “Fixed-time AI” should be considered as the approximate average time of insemination. This should be based on the number of heifers to inseminate, labor, and facilities.

HighLow1 Shot PGLABORCOSTHEAT DETECTION

COMPARISON OF PROTOCOLS FOR BEEF HEIFERS

Low/MediumLowMGA®-PGMediumMediumCIDR®-PG

HEAT DETECT & TAI

MediumMediumMGA®-PG (TAI non-responders 72-84 hr after PG)

MediumHighSelect Synch + CIDR®

(TAI non-responders 72-84 hr after PG)

MediumHighCO-Synch + CIDR®

(TAI at 54 hr after PG with GnRH at TAI)

FIXED-TIME AI (TAI)

MediumMediumMGA®-PG

(TAI at 72 hr after PG with GnRH at TAI)

• The times listed for “Fixed-time AI” should be considered as the approximate average time of insemination. This should be based on the number of heifers to inseminate, labor, and facilities.

HighLow1 Shot PGLABORCOSTHEAT DETECTION

COMPARISON OF PROTOCOLS FOR BEEF HEIFERS

Low/MediumLowMGA®-PGMediumMediumCIDR®-PG

HEAT DETECT & TAI

MediumMediumMGA®-PG (TAI non-responders 72-84 hr after PG)

MediumHighSelect Synch + CIDR®

(TAI non-responders 72-84 hr after PG)

MediumHighCO-Synch + CIDR®

(TAI at 54 hr after PG with GnRH at TAI)

FIXED-TIME AI (TAI)

Heat detect and AI day 7 to 10 and TAI all non-responders 72 - 84 hr after PG with GnRH at TAI.

Heat detect and AI day 33 to 36 and TAI all non-responders 72 - 84 hrs after PG with GnRH at TAI.

Perform TAI at 54 hr after PG with GnRH at TAI.

Perform TAI at 72 hr after PG with GnRH at TAI.

-5 6

GnRH

PG

Cystorelin®, Factrel®, Fertagyl®, OvaCyst®

Estrumate®, In-Synch®, Lutalyse®, ProstaMate®D.J. Schafer and D.J. Patterson Division of Animal Sciences - University of Missouri – Columbia These protocols are recommended by the North Central Region Bovine Reproduction Task Force.

0

… 19 d …

… 19 d … .. 72 hr ..

.. 54 hr ..

.. 72 - 84 hr ..

.. 72 - 84 hr ..

… 19 d …

treatment day

treatment day

treatment day

treatment day

treatment day

treatment day

treatment day

Additional Considerations for Additional Considerations for CattlemenCattlemen

Estrous Synchronization for bull breeding herds

Resynchronization of estrus for non-pregnant cows

Consider fixed-time AI

Work with experts to define reproductive management procedures