1. NEW OPPORTUNITIES TO SYNCHRONIZE ESTRUS AND FACILITATE FIXED-TIME AI
DJ Patterson, MF Smith, and DJ Schafer
Division of Animal Sciences
University of Missouri-Columbia
July 6, 2005

2. reproductive technology in the U.S. beef cattle industry……
The current status of
reproductive technology in the U.S.
beef cattle industry……

3. Reproductive Technologies Available or on the Horizon
Estrus synchronization and AI
Ultrasonography
Sexed semen
Embryo transfer
In vitro production of embryos
Transgenics (pharming)
Cloning
Male fertility

4. The U.S. Beef Herd
69% of cow-calf enterprises are secondary income sources
50% of producers report an established breeding season of specific duration
34% of beef herds are routinely pregnancy checked
10% of beef cattle enterprises utilize AI

5. What’s happening in adoption of technology in the beef industry on a global basis?

6. Total Domestic Sales of Beef Semen
In the U.S. …...
Total Domestic Sales of Beef Semen
1980
1982
1984
1986
1988
1990
1994
1996
1998
2000
1992
Hough,, 2002

7. Comparison of AI Use In Beef Cattle (U.S. vs. Brazil)

8. Import and Domestic Beef Semen Sales (units sold)
1993
1,117,798
2003
1,025,116
1993
1,874,996
2003
4,896,204
-8% change
+161% change
From NAAB, 2003; ASBIA, 2003

9. Unless efforts are taken to implement change in the U. S
Unless efforts are taken to implement change in the U.S. beef cattle industry, the products of our research and technology may be exported to more competitive international markets (Patterson et al., 2000).

10. Why are we here?

11. Artificial insemination and estrus synchronization are generally regarded as the most important and applicable of all available biotechnologies to the beef cattle industry (Seidel, 1995).

12. From NAHMS Survey, 1998

13. Improvements in methods to synchronize estrus create the opportunity to significantly expand the use of AI in the U.S. cowherd ………………….

14. A unique point in time for the U.S. beef industry………
Availability of tools and understanding of methods to control the estrous cycle in cattle
A changing market structure that recognizes and rewards quality

15. A unique point in time………
If we don’t impact use of AI among beef producers in the U.S. in the near future, will we ever?

16. The challenge of transferring technology (estrus synchronization and AI) to the private sector exceeds the task of research and development of still newer technologies……….

17. Collectively
Adopt common terminology regarding the various estrus synchronization protocols
Identify and agree upon short lists of protocols
heifers and cows
heat detect and AI vs fixed-time AI
Work to overcome the attitude of “What will this cost me?” ….to… “ I’m willing to make an investment in my herd”

18. Effective Estrus Synchronization Programs for Beef Cattle
Facilitate AI & ET
Reduce time required to detect estrus
Cycling females conceive earlier in the breeding period
Induce cyclicity in peripubertal heifers and anestrous postpartum cows

19. Objective: Development of highly effective & economical estrus synchronization programs
Peripubertal heifers
Postpartum cows
Anestrus and estrous cycling
Excellent pregnancy rates

20. Products Currently Available
Prostglandin
Lutalyse, Estrumate, ProstaMate, In Synch, EstroPlan
GnRH
Cystorelin, Factrel, Fertagyl, OvaCyst
Progestins
MGA
CIDR

21. What We Know About MGA . . .

22. Progesterone MGA (melengestrol acetate) Pregn-4-ene-3, 20-dione
CH3
MGA
(melengestrol acetate)
6-methyl-17-alpha-acetoxy-16-methylene-pregn-4, 6-diene-3, 20-dione C O
CH3
CH2

23. What We Know About MGA . . .
Induces puberty in beef heifers (Imwalle et al., 1998)
Prevents expression of behavioral estrus (Zimbelman and Smith, 1966; Imwalle et al., 2002)
Blocks the preovulatory surge of LH (Imwalle et al., 2002)
Blocks ovulation (Zimbelman and Smith, 1966; Imwalle et al., 2002)

24. HEIFERS

25. Reproductive Tract Scores (RTS)4 5
Length 30
> 32
Height 16 20
Width 12 15
Ovarian Measurement (mm)
Description Infantile Prepubertal Peripubertal
Cycling
Uterine horns Immature < 20 mm diameter No tone mm diameter No tone mm diameter Slight tone 30 mm diameter good tone
> 30 mm diameter
Ovarian Structures
No palpable follicles
8 mm follicles
8-10 mm follicles
> 10 mm follicles
CL possible
CL present
Adapted from Anderson et al., 1991

26. Reproductive Tract Scores (RTS) Summary
Pelvic Height (cm)
13.9a
14.1a
14.5b
14.7c
Pelvic Width (cm)
10.9a
11.2a
11.4b
11.7c
Pelvic Area (cm2)
152a
158a
166b
172c
Estrous Response (%)
54a
66b
76c
83d
86d
Weight (lb)
594a
620b
697c
733d
755d
RTS 1 2 3 4 5 n 61
278
1103
494
728
a, b, c, d Numbers with different superscripts within a column differ (P < 0.05)
Adapted from Patterson and Bullock, 1995

27. Comparison of reproductive performance in herds using natural service or synchronization and AI on replacement heifers by RTS
Exposed
21-d PR2
42-d PR3
TPR4
RTS1
NS5
(n)
SAI6 NS
(%)
SAI 1 8 55
38a
42a
63c
55c
63e
60e 2
108
661
31a
52b
54c
68d
75e
82e 3
336
3320
41a
58b
65c
74d
87f 4
322
3629
48a
62b
72c
77d
91e 5
242
2835
50a
64b
74c
80d
88e
TOT
1016
10500
44a
61b
68c
73d
85e
87e
a,b Means within rows for 21-d PR with different superscripts differ (P < .05)
c,d Means within rows for 42-d PR with different superscripts differ (P < .05)
e,f Means Within rows for TPR with different superscripts differ (P < .05)
From Randle and Patterson, 2005

28. Synchronized Estrus estrus PG MGA (14 days) 1 14 16 20 31 33 36
Treatment days
Brown et al., 1988

29. MGA-PG 14-19 d Improved estrous response Similar fertility
More heifers in heat
Similar fertility
No change in conception or pregnancy rate
Improved synchrony
More heifers in heat in a shorter time
(Deutscher et al., 2000; Lamb et al., 2000)

30. PG MGA (14 days) MGA (14 days) PG GnRH MGA-PG 1 14 33 MGA Select
Treatment days
MGA (14 days) 1 14 26 33 PG
GnRH
Wood et al., 2001

31. PG Follicle diameter (mm) Day of treatment ESTRUS Wood et al., 2001 55 10 15 20 25 30 35 16 17 18 19 21 22 23 24 26 27 28 29 31 32 33 34 36 37 38 39 40
Day of treatment
Follicle diameter (mm)
ESTRUS PG
Wood et al., 2001

32. PG GnRH Follicle diameter (mm) Day of treatment Wood et al., 2001 5 105 10 15 20 25 30 35 16 17 18 19 21 22 23 24 26 27 28 29 31 32 33 34 36 37 38 39 40
Day of treatment
Follicle diameter (mm)
ESTRUS PG
GnRH
Wood et al., 2001

33. When to Add GnRH to an MGA-PG Protocol for Heifers
Consideration of
Age
Weight
Reproductive tract score (RTS)
Pubertal status
Wood et al., 2000; Kojima et al., 2001

34. How do MGA- and CIDR-based protocols compare in heifers?

35. Experimental Protocols
MGA Select
GnRH PG
MGA (14 days)
days days .. ..
14-d CIDR
GnRH PG
CIDR (14 days)
days days .. ..
Treatment day
Kojima et al., 2004

36. Experimental Procedures
352 yearling crossbred beef heifers at three locations Location 1 n = 154 (Southeast Missouri) Location 2 n = 113 (North Dakota) Location 3 n = 85 (North central Missouri)
Heifers were assigned to one of two treatments (MGA or CIDR) by age and weight
Kojima et al., 2004

37. Summary for Timing of AI % of Heifers Inseminated80
CIDR (n = 177)
MGA (n = 175)
69% 70 60
53% 50
% of Heifers Inseminated 40 30
21% PG 20
15%
16%
10%
10% 10 5% 0% 1% 1 2 3 4 5+
Days after PG
No treatment x location effect (P > 0.10); therefore, data were pooled
Distribution of AI dates were different between MGA- and CIDR-treated heifers (P < 0.02)
Kojima et al., 2004

38. Estrous Response, AI Pregnancy, and Final Pregnancy Rates
154/177 (87 %)
112/177 (63 %)a
164/177 (93 %)
CIDR
147/175 (84 %)
83/175 (47 %)b
159/175 (91 %)
MGA
301/352 (86 %)
195/352 (55 %)
323/352 (92 %)
Total
a, b P = 0.01
Diff.
+ 3 %
+ 16 %
+ 2 %
Kojima et al., 2004

39. Summary In yearling beef heifers:
CIDR-GnRH-PG improved synchrony of estrus compared with MGA Select
CIDR-GnRH-PG improved AI pregnancy rate over MGA Select
Kojima et al., 2004

40. COWS

41. How do MGA-based protocols perform in synchronizing estrus in mixed populations of postpartum beef cows? (estrous cycling and anestrus)

42. Precise control of the bovine estrous cycle requires the synchronization of both luteal and follicular functions.

43. Protocols MGA Select GnRH PG PG 7-11 Synch GnRH PG Treatment day
MGA (14 days) PG
7-11 Synch
GnRH PG
MGA
Treatment day
Kojima et al., 2000; Wood et al., 2001

44. These protocols were hypothesized to……
Improve estrous response and pregnancy rates during the synchronized period
Effectively synchronize estrus in estrous cycling cows
Induce cyclicity in anestrous cows
Prevent short cycles among anestrous cows induced to ovulate

45. These protocols were hypothesized to……
Reduce the period of time required to detect estrus
Facilitate fixed-time AI

46. How do MGA Select and 7-11 Synch compare on the basis of synchronized estrus and pregnancy rates in postpartum beef cows with AI performed on the basis of detected estrus?

47. MGA Select vs. 7-11 Synch AI performed after detected estrus
No difference in estrous response
Improvement in synchrony of estrus among 7-11 Synch treated cows (P < 0.01)
No difference in synchronized conception or pregnancy rates
No difference in final pregnancy rate
Stegner et al., 2004

48. Stegner et al., 2004 45 MGA Select 40 7-11 Synch 35 30 25
Cows in estrus, no 20 15 10 5 12 24 36 48 60 72 84 96
108
120
132
144 NR
Time after PG, h
Stegner et al., 2004

49. Pregnancy Rates of Cows Inseminated after Detected Estrus
No. (%)
MGA Select
Patterson et al., /
Patterson et al., /
Stegner et al., /
Combined total 195/
7-11 Synch
Kojima et al., /
Stegner et al., /
Combined total 101/

50. How do MGA Select and 7-11 Synch compare on the basis of pregnancy rates in postpartum beef cows inseminated at predetermined fixed times?

51. MGA Select Time of AI after PG Pregnancy rate 48 hr 46% 72 hr 61%
Stevenson et al., 2003
48 hr
46%
Perry et al., 2002
72 hr
61%
Stegner et al., 2003
72 hr
80 hr
64%
50%

52. 7-11 Synch Time of AI after PG Pregnancy rate 48 hr 72% 48 hr 60 hr
Hixon et al., 2001
48 hr
72%
Kojima et al., 2003
48 hr
60 hr
52%
59%
Unpublished data., 2002
60 hr
61%
Kojima et al., 2002
60 hr
63%
Kojima et al., 2003
60 hr
63%

53. Bader et al. (2004) compared pregnancy rates resulting from fixed-time AI among suckled beef cows assigned to the MGA Select or 7-11 Synch protocols.

54. Protocols AI MGA Select GnRH GnRH PG AI PG 7-11 Synch GnRH GnRH PG
MGA (14 days)
… … … 72 hr AI PG
7-11 Synch
GnRH
GnRH PG
MGA
… … 60 hr
Treatment day
Bader et al., 2004

55. Days postpartum, body condition score, and estrous-cycling status prior to initiation of synchronization treatments
Location
Days
postpartum
Body
condition score
Estrous cycling
No. % 1
50 ± 1.0a
5.8 ± 0.1a
64/208
31a 2
39 ± 1.3b
31/122
25a,b 3
36 ± 1.5b
5.4 ± 0.1b
18/92
20b
Combined
42 d
5.7
113/422 27
a,b(P < 0.05)
Bader et al., 2004

56. Fixed-time AI and final pregnancy rates
Location
Treatment
Fixed-time AI
Final
No. % 1
7-11 Synch
64/104 62
95/104 91
MGA Select
68/104 65
101/104 97 2
34/60 57
57/59
43/62 69
60/62 3
30/45 67
43/45 96
31/47 66
42/47 89
Combined
128/209 61
195/208 94
142/213
203/213 95
Bader et al., 2004

57. Fixed-time AI pregnancy rate based on pretreatment estrous cyclicity status
MGA Select
7-11 Synch
Cycling
Anestrus
Location
No. Preg %
No Preg 1
20/30 67
48/74 65
24/34 71
40/70 57 2
12/16 75
31/46
9/15 60
25/45 56 3
6/8
25/39 64
8/10 80
22/35 63
Combined
38/54 70
104/159
41/59 69
87/150 58
Bader et al., 2004

58. Pros and Cons Advantages Disadvantages
MGA Select - effective in mixed treatment length populations MGA intake synchrony of estrus fertility after treatment Synch effective in mixed multiple populations animal handlings exceptional synchrony drug costs of estrus MGA intake fertility after treatment treatment duration

59. Pregnancy rates after AI based on detected estrus or at predetermined fixed times
No. (%)
7-11 Synch
Detected estrus 101/
Fixed-time AI 446/
MGA Select
Detected estrus 195/
Fixed-time AI 281/

60. Implications
This sequential approach to estrous cycle control (progestin-GnRH-PG) effectively synchronizes estrus with resulting high fertility among mixed populations of estrous cycling and anestrous postpartum beef cows.

62. How do MGA- and CIDR-based protocols compare on the basis of pregnancy rates in postpartum beef cows inseminated at predetermined fixed times?

63. MGA Select vs. CO-Synch + CIDR Schafer, 2005
GnRH PG
GnRH
MGA (14 d) AI
………
GnRH PG
GnRH
CIDR (7 d) AI
……….
Treatment day

64. Timing of Insemination
Time of AI Pregnancy
Protocol after PG rate
MGA Select
Stevenson et al., h %
Perry et al., h %
Bader, h %
Stegner et al., h %
80 h %
CO-Synch + CIDR
Lamb et al., h %
48 h %
Bremer et al., h %
66 h %
Larson et al., h %

65. MGA Select vs. CO-Synch + CIDR Schafer, 2005AI
GnRH PG
GnRH
MGA (14 d)
…… 72h AI
GnRH PG
GnRH
CIDR (7 d)
…... 66h
Treatment day

66. Experimental Procedures Schafer, 2005
Animals: Crossbred, suckled, beef cows (n = 650) at four locations were assigned to treatment within age groups by calving date and BCS

67. Experimental Procedures Schafer, 2005
Four different AI sires were used
Location 1 = 3
Location 2 = 1
Location 3 = 1
Location 4 = 1
One of the sires that was used at location 1 was the same sire used at Locations 3 & 4

68. Experimental Procedures Schafer, 2005
Cows were exposed to fertile bulls 14 d after AI
Pregnancy rate to fixed-time AI was determined with ultrasound 40 – 45 d after insemination

69. Number of cows at each location, DPP, BCS, and estrous-cycling status prior to initiation of synchronization treatments (Schafer, 2005)
Location
Days
postpartum
Body
condition score
Estrous cycling
No % 1 46
5.7
112/210 53 2 33
6.0
63/158 40 3 44
5.3
31/88 35 4 43
156/194 80
Combined
42 d
5.5
362/650 56

70. Fixed-time AI pregnancy rates between treatments and among locations (Schafer, 2005)
No. % 1
MGA Select
70/106 66
CO-Synch+CIDR
67/104 64 2
53/80
56/78 72 3
26/45 58
29/43 67 4
52/96 54
62/98 61

71. Pregnancy rates to fixed-time AI Schafer, 2005
Treatment No %
MGA Select /
CO-Synch+CIDR /

72. Fixed-time AI pregnancy rate based on pretreatment estrous cyclicity status (Schafer, 2005)
MGA® Select
CO-Synch+CIDR
Cycling
Anestrus
Location
No. Preg %
No Preg 1
38/62 61
32/44 73
30/50 60
37/54 69 2
20/29
33/51 65
25/34 74
31/44 70 3
11/16
15/29 52
8/15 53
21/28 75 4
41/78
11/18
50/78 64
12/20
Combined
110/185 59
91/142
113/177
101/146

73. Conclusions Schafer, 2005
The results from this experiment demonstrate that comparable pregnancy rates to fixed-time AI can be achieved using the MGA Select or CO-Synch+CIDR protocols to synchronize estrus in postpartum beef cows.

74. Do we know what to expect at calving from cows that conceive on the same day to the same sire?

75. Days relative to 285 d gestation due date; Bader et al., 20045 10 15 20 25
-13
-12
-11
-10 -9 -8 -7 -6 -5 -4 -3 -2 -1 1 2 3 4 6 7 8 5 10 15 20 25
-10 -9 -8 -7 -6 -5 -4 -3 -2 -1 1 2 3 4
A; Angus; +6.2 BW
, 20 d
B; Angus; +3.3 BW
, 17 d 5 10 15 20 25
-11
-10 -9 -8 -7 -6 -5 -4 -3 -2 -1 1 2 3 4 5 10 15 20 25
-10 -9 -8 -7 -6 -5 -4 -3 -2 -1 1 2 3 4 6 7 8 9
C; Red Angus; –1.5 BW, 2 CED
, 15 d
D; Simmental; -0.6 BW, CE
, 19 d 25
B; Angus; +3.3 BW
, 17 d 20
% of AI calves born 15 10 5
-11
-10 -9 -8 -7 -6 -5 -4 -3 -2 -1 1 2 3 4 5 6
Days relative to 285 d gestation due date; Bader et al., 2004

76. Location 1; Sire A (Angus) BW EPD -0
Location 1; Sire A (Angus) BW EPD -0.3; CED = +11 Range Mean = 281
Location 1; Sire B (Angus) BW EPD +3.5; CED = +6 Range Mean = 281
Location 1; Sire C (Angus) BW EPD -1.1; CED = +11 Range Mean = 281
Location 2; Sire D (Red Angus) BW EPD +2.3; CED = -2 Range Mean = 283
Location 3; Sire B (Angus) BW EPD +3.5; CED = +6 Range Mean = 283
Location 4; Sire B (Angus) BW EPD +3.5; CED = +6 Range Mean = 284

77. Calving Distribution of AI sired calves (Schafer et al., 2005)

78. Consider the impact of estrus synchronization on calving distribution………

79. Hughes, 2005
Opportunities for increasing profits lie in managing females from the later calving intervals forward toward the first and second calving intervals.
High production herds see 61% of the calves born by day 21, 85% by day 42 and 94% by day 63.

80. Stegner et al., 2004 100 MGA Select 90 7-11 Synch 80 70
Cows calving, % 60 50 40 30 20 10
First 15 d
First 30 d
Calving period
Stegner et al., 2004

81. Calving distribution for locations 1, 2, & 3 (Schafer, 2005)
Cumulative Calf % by:
day 15 = 64%
day 21 = 70%
day 30 = 77%
day 42 = 91%

82. MU Forage Systems Research Center cumulative calf crops

83. Cumulative calf crops (MU Thompson Farm) for the first 46 days over 10 calving seasons

84. Conclusions and Implications

85. Treatment Estrous response Pregnancy rate AI based on
Estrous response and fertility in postpartum beef cows after treatment with various estrus synchronization protocols.
Treatment Estrous response Pregnancy rate
AI based on
detected estrus No % No %
2 shot PG
Select Synch*
MGA-PG
MGA Select
7-11 Synch
241/
353/
305/
275/
142/
147/
237/
220/
195/
101/
Fixed-time AI
MGA Select
7-11 Synch
CO-Synch + CIDR
482/
446/
214/
* DeJarnette and Wallace

86. Treatment Estrous response Pregnancy rate
Estrous response and fertility in postpartum beef cows after treatment with various estrus synchronization protocols.
Treatment Estrous response Pregnancy rate
AI based on detected estrus No % No %
2 shot PG
Select Synch*
MGA-PG
MGA Select
7-11 Synch
241/
353/
305/
275/
142/
147/
237/
220/
195/
101/
Fixed-time AI
MGA Select
7-11 Synch
CO-Synch + CIDR
482/
446/
214/
* DeJarnette and Wallace

87. Total 786 1217 CO-Synch + CIDR Results (FTAI @ 66 hr after PG)
Herd (Year)
No. Pregnant
Total No.
Percentage
1 (F03) 41 51 80
2 (S04) 67
104 64
3 (S04) 56 78 72
4 (S04) 29 43
5 (S04) 52 96 63
6 (S04) 60 90
7 (F04) 31 48 65
8 (F04) 87
143 61
9 (F04)
100
10 (F04) 44 69
11 (F04) 68
111
12 (F04) 47
13 (S05
224
Total
786
1217

88. Research is underway to develop new protocols for heifers that will facilitate fixed-time AI ….
The technology now exists to successfully inseminate postpartum beef cows at predetermined fixed times with resulting high pregnancy rates

89. Improvements in methods to synchronize estrus create the opportunity to significantly expand the use of AI in the U.S. cowherd

90. Acknowledgements Faculty, Students, & Staff
Jon Bader Dr. George Perry
Roger Eakins Daniel Schafer
Dr. Mark Ellersieck Jon Schreffler
Freddie Kojima Dr. Mike Smith
Dr. Matthew Lucy Jacob Stegner
David McAtee Stacey Wood (Follis)

91. Acknowledgements Research Support Cooperators
Select Sires, Inc. 4-M Ranch
KABA/Select Sires, Inc. John Ranch
ABS Global Jim Wallis Farms
Merial Jim Clement, DVM
Pfizer Animal Health SEMO University
USDA-NRI MFA, Inc.
MU Farms & Centers

92. Acknowledgements Beef Reproduction Leadership Team AI industry
Pharmaceutical industry
Veterinary practitioners
North Central Region Bovine Reproduction Task Force