1. Reproductive Management for Beef Females
Cliff Lamb
Assistant Director and Professor

2. Semen Sales in USA and Brazil from 1995 to 2011
(NAAB and ASBIA, 2011)

3. Estrous Synchronization and AI in Beef Cattle

4. Definitions Synchronization Rate:
% of females detected in estrus compared to total number synchronized.
Conception Rate:
% of females pregnant compared to number of females inseminated.
Pregnancy Rate:
% of females pregnant compared to total number synchronized.

5. Effect of synchronization rate on pregnancy rates

6. Effect of synchronization rate on pregnancy rates

7. TAI in Bos taurus cows

8. Cidirol

9. TAI in Bos taurus heifers

10. Cidirol

11. Can we resynchronize estrus in non-pregnant cows?

12. Protocol for Resynchronization after TAI - Cows
7-d Co-Synch + CIDR protocol
CIDR
Heat detect and AI
Days relative to TAI

13. Protocol for Resynchronization after TAI - Heifers
7-d Co-Synch + CIDR protocol
CIDR
Heat detect and AI
Days relative to TAI

14. Protocol for Resynchronization after TAI
(Larson et al., 2009)

15. Does estrous synchronization affect subsequent fertility?

16. Answers to field results from commercial producers
438 suckled cows were estrous synchronized using the 7-day CO-Synch + CIDR Protocol.
TAI &
GnRH
GnRH
PGF
CIDR

17. Pregnancy Rates
n=275
90% Overall pregnancy rate ??
n=85
n=37
n=34

18. Estrus response of cows following the 7-day CO-Synch+CIDR protocol
97.5% return to estrus rate!!
Average Interval to estrus = 20.9 days

19. Economics of implementing TAI program

20. Impact of Fixed-Time AI on Calving and Weaning
Control
Natural mating
TAI + GnRH
GnRH
PGF
TAI
Natural mating
CIDR
(Rodgers et al., 2011)

21. Impact of Fixed-Time AI on Calving and Weaning
(Rodgers et al., 2011)

22. Impact of Fixed-Time AI on Calving Distribution
44% vs. 25%

23. Impact Calving Distribution on Calf Value

24. Impact of Fixed-Time AI on Calving and Weaning
Treatment
Item
Control
TAI
No. of cows
615
582
Weaning rate, % 78 84
Weaning weight, lb
176 ± 4a
193 ± 4b
ab Means within row differ (P < 0.01)
17 kg
(Rodgers et al., 2011)

25. (Rodgers et al., 2011)

26. Change in value based on herd sire costs
Bull Value
Item
$2,500
$3,500
$4,500
Increased returns (increased value of AI calves)
$58.33
Decreased costs decreased costs of clean-up bulls)
$29.55
$39.29
$49.04
Decreased returns (Attributed to fewer clean-up bulls included in decreased costs calculation)
$0.00
Increased costs (additional labor, semen, AI supplies, etc.)
$46.10
Gain per cow exposed to AI
$41.78
$51.52
$61.27

31. Can I use sexed semen in beef cattle operations?

32. Semen sorting overview
MoFlo® Hands-On Training Course
Nozzle
Forward Fluorescence
Photodiode DNA Content
Laser beam
Drop Delay
Side Fluorescence Orientation
Objective
Pulse of Charge Applied
Last Attached Drop
Charged
Deflection
Plates
Sorting Overview
The sorting takes place following the analysis in the Illumination Chamber. When a cell of interest is detected by the lasers and optics, a pulse of charge is sent through the stream when this cell of interest reaches the last attached drop. The droplet then breaks off with a charge that can be either positive or negative, depending on the sort direction. The droplets fall through the electric field created by the charge plates, and get deflected accordingly. The cells are then collected in the sample tubes.
The sorting function involves many facets of the MoFlo that require very precise timing and calibration. The stability of the fluidics and droplet formation are critical with a jet-in-air sorter. Your MoFlo has been engineered to provide an extremely stable droplet break-off and charge on the droplets of interest. This translates directly to your sort purity.
An accurate drop delay assessment is also critical to high sort purity. The drop delay defines the time duration for a particle to travel from the interrogation point at the laser to the “last attached drop”.
With a stable fluidics and an accurate drop delay, cell sorting can reach very high purities of greater than 99%. Also, recoveries are optimized with stable fluidics and an accurate drop delay.
These concepts described above are covered in detail throughout this module. + - +
Waste Catcher + - + -
Sort Receptacle 32

33. Gender ratio after 20% of cows are inseminated to sexed semen
(Hall et al., 2010)

34. Embryo Production of Superovulated Angus Cows
32.4%
49.5% ** **
Category
** Treatments differ (P < 0.05)

35. Recommendations for Embryo Transfer
Utilize only in donors cows with known prolific production (average >10 transferable embryos per collection).
Inseminate at 0, 12, and 24hr after estrus.
Do not expect similar fertilization rates to conventional semen.

36. Heifer Development

37. Relationship between time of calving and lifetime production
(Lesmeister et al., 1973)

38. Influence of calving period on reproductive longevity
(Cushman et al., 2012)

39. Influence of calving period on weaning weights
(Cushman et al., 2012)

40. Factors affecting attainment of puberty
Body weight
Age
Genetics
Nutrition
Reproductive management
Rate of gain
Plane of nutrition
Body composition
Animal handling

41. Factors affecting attainment of puberty
Body weight
Age
Genetics
Nutrition
Reproductive management
Rate of gain
Plane of nutrition
Body composition
Animal handling

42. Factors affecting attainment of puberty
Body weight
Age
Genetics
Nutrition
Reproductive management
Rate of gain
Plane of nutrition
Body composition
Animal handling

43. Effect of timing of gain on attainment of puberty and reproductive performance
Lynch et al., 1997 JAS 75:
The objective of this study is to determine the influence of supplemental feeding of conserved perennial peanut forage on growth performance and age at puberty in growing beef cattle heifers.

44. Effect of Timing of Gain on Reproductive Performance
ADG, kg/d d0-112
EVENGAIN
LATEGAIN – 0.11
ADG, kg/d d
EVENGAIN – 0.45
LATEGAIN – 0.91
ADG, lbs/d d0-168
LATEGAIN – 0.45
EVENGAIN
LATEGAIN
(Lynch et al., 1997)

45. Effect of Timing of Gain on Reproductive Performance
Year 1
ADG, kg/d d0-112
EVENGAIN
LATEGAIN – 0.26
ADG, kg/d d
EVENGAIN – 0.80
LATEGAIN – 0.95
ADG, lbs/d d0-168
EVENGAIN – 0.57
LATEGAIN – 0.49
EVENGAIN
LATEGAIN
(Lynch et al., 1997)

46. Effect of Timing of Gain on Reproductive Performance
Year 2
ADG, kg/d d0-112
EVENGAIN
LATEGAIN – 0.05
ADG, kg/d d
EVENGAIN – 0.74
LATEGAIN – 1.30
ADG, lbs/d d0-168
EVENGAIN – 0.53
LATEGAIN – 0.50
EVENGAIN
LATEGAIN
(Lynch et al., 1997)

47. Effect of Timing of Gain on Reproductive Performance
Item EVENGAIN LATEGAIN
Age at puberty, d
Year
Year a b
Weight at puberty, kg
Year
Year
ab Means within row differ (P < 0.01)
(Lynch et al., 1997)

48. Effect of Timing of Gain on Reproductive Performance
Item EVENGAIN LATEGAIN
First service PR, %
Year
Year
Overall PR, %
Year
Year
(Lynch et al., 1997)

49. Cassady et al., 2009, JAS 87:2255-2261 and JAS 2262-2273
Estrous cyclicity responses of heifers of distinct body conditions to energy restriction and repletion.
Cassady et al., 2009, JAS 87: and JAS
The objective of this study is to determine the influence of supplemental feeding of conserved perennial peanut forage on growth performance and age at puberty in growing beef cattle heifers.

50. BCS 3
BCS 5
BCS 7

51. Resumption of estrous cycles Termination of estrous cycles
Design
Restriction
Re-feeding
(FAT) ??
BCS 7
BCS 5
Resumption of estrous cycles
(MODERATE)
Termination of estrous cycles
Cassady et al., (2009)

52. Change in BW, BCS and days to anestrus during feed restriction
Treatments
 Item
MODERATE
FAT
Initial BW, kg
425a
515b
Initial BCS
5.0a
7.1b
BW at anestrus, kg
354
380
BCS at anestrus
3.1
3.3
Days to anestrus
66.5a
155.9b
NEW
Cassady et al., (2009)

53. Change in BW, BCS and days to 1st estrous cycle after initiation of feed repletion
Treatments
 Item
MODERATE
FAT
BW at anestrus, kg
354
380
BCS at anestrus
3.1
3.3
BW at 1st estrous cycle, kg
455a
513b
BCS at 1st estrous cycle
5.2a
6.0b
Days to 1st estrous cycle
67.7
78.9
NEW
Cassady et al., (2009)

54. Conclusions Restriction Re-feeding BCS 7 BCS 6 BCS 5 BCS 5 BCS 3
Cassady et al., (2009)

55. The impact of animal handling on fertility

57. Acclimation of Heifers
P < 0.01 ** ** **
Cooke et al. (2009)

58. Acclimation of Heifers
Pregnancy during the breeding season
P < 0.01 ** ** **
Cooke et al. (2009)

60. Acclimation of Heifers** **
Treatment x Month P = 0.02
** P < 0.01 **
Cappellozza et al. (2011) – Abstract #545

61. Thank You!
Contact Information:
Cliff Lamb
University of Florida
3925 HWY 71
Marianna, FL 32446
Tel: