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Reproductive Management for Beef Females
Cliff Lamb
Assistant Director and Professor
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 20110
2
4
6
8
10
12
14
USA Brazil
Year
Un
its
of
sem
en,
x106
Semen Sales in USA and Brazil from 1995 to 2011
(NAAB and ASBIA, 2011)
Estrous Synchronization and AI in Beef Cattle
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.
Effect of synchronization rate on pregnancy rates
Effect of synchronization rate on pregnancy rates
TAI in Bos taurus cows
Cidirol
TAI in Bos taurus heifers
Cidirol
Can we resynchronize estrus in non-pregnant cows?
CIDRHeat detect
and AI
TAI
Protocol for Resynchronization after TAI - Cows
0 13 20 23
7-d Co-Synch + CIDR protocol
Days relative to TAI
CIDRHeat detect
and AI
TAI
Protocol for Resynchronization after TAI - Heifers
0 12 19 22
7-d Co-Synch + CIDR protocol
Days relative to TAI
15 16 17 18 19 20 21 22 23 24 25 26 27 NR0
10
20
30
40
50
60
1 1 2 2
6
15
2119
8
3 31 0
36
0 0 0 0 0 0
5
55
25
8
2 1 0
29
No CIDR
CIDR
Days after TAI
No
. o
f co
ws
Protocol for Resynchronization after TAI
(Larson et al., 2009)
Does estrous synchronization affect subsequent fertility?
Answers to field results from commercial producers
438 suckled cows were estrous synchronized using the 7-day CO-Synch + CIDR Protocol.
PGFGnRHTAI &GnRH
CIDR
TAI First 21 d 21-42 d 42-63 d0
10
20
30
40
50
60 57
8
18
7
Calving group
Per
cen
t
n=275
n=85
n=37 n=34
90% Overall pregnancy rate
??
Pregnancy Rates
17 18 19 20 21 22 23 24 250.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
2.55.0
7.5
20.0
37.5
10.07.5
5.02.5
Days after GnRH
Per
cen
t
97.5% return to estrus rate!!
Estrus response of cows following the 7-day CO-Synch+CIDR protocol
Average Interval to estrus = 20.9 days
Economics of implementing TAI program
(Rodgers et al., 2011)
Control
CIDR Natural matingGnRH PGF
TAI + GnRH
TAI
Natural mating
Impact of Fixed-Time AI on Calving and Weaning
0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 57 60 63 66 69 72 75 78 81 84 87 90 93 96 990
10
20
30
40
50
60
70
80
90
100
TAI Control
Days of calving season
Cu
mu
lati
ve
pe
rce
nta
ge
of
co
ws
ca
lvin
g
Impact of Fixed-Time AI on Calving and Weaning
(Rodgers et al., 2011)
Impact of Fixed-Time AI on Calving Distribution
1-10 11-20 21-30 31-40 41-50 51-60 61-70 >700
10
20
30
40
2123
16 18
53 3
2
7
18
29
25
8
2 3 2
Days of the calving season
%
44% vs. 25%
Impact Calving Distribution on Calf Value
0 to 25 26 to 50 51 to 75 >75300
350
400
450
500
550
600
$518$509
$457
$420
Days of the calving season
$
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)
Impact of Fixed-Time AI on Calving and Weaning
(Rodgers et al., 2011)
17 kg
1 2 3 4 5 6 7 8 Overall-$20
$0
$20
$40
$60
$80
$100
$120
$140
$160
$55
$19
$72
$139
-$6
$36$30
$47 $49
Location
Net
gai
n o
r lo
ss
(Rodgers et al., 2011)
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 $58.33 $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 $0.00 $0.00
Increased costs (additional labor, semen, AI supplies, etc.)
$46.10 $46.10 $46.10
Gain per cow exposed to AI $41.78 $51.52 $61.27
Can I use sexed semen in beef cattle operations?
Semen sorting overview
Nozzle
Forward Fluorescence Photodiode DNA Content Laser beam
Sort Receptacle
Waste Catcher
Charged
Deflection
Plates
Last Attached Drop
Pulse of Charge Applied
+
+
+
+
-
-
-
Drop Delay
Side Fluorescence Orientation
Objective
Year 1 Year 2 Year3 Overall0
10
20
30
40
50
60
70
80
90
78
68
62
69
4750
56
51
Sexed semen Control
Per
cen
t ag
e fe
mal
e ca
lves
Gender ratio after 20% of cows are inseminated to sexed semen
(Hall et al., 2010)
Embryo Production of Superovulated Angus Cows
Total Transferable Unfertilized Degenerate0
2
4
6
8
10
12
1411.7
6.5
3.12.0
12.0
4.5
6.3
1.0
ConventionalSexed
No.
of
em
bry
os/o
va
Category
****
** Treatments differ (P < 0.05)
32.4%49.5%
Heifer Development
(Cushman et al., 2012)
Influence of calving period on reproductive longevity
(Cushman et al., 2012)
Influence of calving period on weaning weights
Body weight Age Genetics Nutrition Reproductive management Rate of gain Plane of nutrition Body composition Animal handling
Factors affecting attainment of puberty
Body weight Age Genetics Nutrition Reproductive management Rate of gain Plane of nutrition Body composition Animal handling
Factors affecting attainment of puberty
Body weight Age Genetics Nutrition Reproductive management Rate of gain Plane of nutrition Body composition Animal handling
Factors affecting attainment of puberty
Effect of timing of gain on attainment of puberty and reproductive performance
Lynch et al., 1997 JAS 75:1715-1722
d 0 d 112 d 168250
300
350
Feeding Period
Bo
dy
we
igh
t, k
g
ADG, kg/d d0-112
EVENGAIN - 0.45LATEGAIN – 0.11
ADG, kg/d d112-168
EVENGAIN – 0.45LATEGAIN – 0.91
ADG, lbs/d d0-168
EVENGAIN – 0.45LATEGAIN – 0.45
EVENGAIN
LATEGAIN
Effect of Timing of Gain on Reproductive Performance
(Lynch et al., 1997)
d 0 d 112 d 168250
300
350
400
Feeding Period
Bo
dy
we
igh
t, k
g
ADG, kg/d d0-112
EVENGAIN - 0.45LATEGAIN – 0.26
ADG, kg/d d112-168
EVENGAIN – 0.80LATEGAIN – 0.95
ADG, lbs/d d0-168
EVENGAIN – 0.57LATEGAIN – 0.49
EVENGAIN
LATEGAIN
Effect of Timing of Gain on Reproductive Performance
(Lynch et al., 1997)
Year 1
d 0 d 112 d 168200
250
300
350
Feeding Period
Bo
dy
we
igh
t, k
g
ADG, kg/d d0-112
EVENGAIN - 0.39LATEGAIN – 0.05
ADG, kg/d d112-168
EVENGAIN – 0.74LATEGAIN – 1.30
ADG, lbs/d d0-168
EVENGAIN – 0.53LATEGAIN – 0.50
EVENGAIN
LATEGAIN
Effect of Timing of Gain on Reproductive Performance
(Lynch et al., 1997)
Year 2
Effect of Timing of Gain on Reproductive Performance
Item EVENGAIN LATEGAIN
Age at puberty, dYear 1 388 384Year 2 386a 407b
Weight at puberty, kg Year 1 330 315Year 2 314 314
(Lynch et al., 1997)
ab Means within row differ (P < 0.01)
Effect of Timing of Gain on Reproductive Performance
Item EVENGAIN LATEGAIN
First service PR, %Year 1 55.3 55.5Year 2 56.4 71.1
Overall PR, %Year 1 87.2 86.8Year 2 87.5 87.5
(Lynch et al., 1997)
Estrous cyclicity responses of heifers of distinct body conditions to energy restriction
and repletion.
Cassady et al., 2009, JAS 87:2255-2261 and JAS 2262-2273
BCS 3
BCS 5
BCS 7
Design
BCS 7
BCS 5
Restriction Re-feeding
Termination of estrous cycles
Resumption of estrous cycles
??(FAT)
(MODERATE)
Cassady et al., (2009)
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
Change in BW, BCS and days to anestrus during feed restriction
Cassady et al., (2009)
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
Change in BW, BCS and days to 1st estrous cycle after initiation of feed repletion
Cassady et al., (2009)
The impact of animal handling on fertility
Acclimation of Heifers
August September October December0
20
40
60
80
100Acclimated Control
% o
f p
ub
erta
l hei
fers
Cooke et al. (2009)
P < 0.01
****
**
Acclimation of Heifers• Pregnancy during the breeding season
1 2 3 4 5 6 7 8 90
20
40
60
80
100 Acclimated Control
Week of the breeding season
% o
f p
reg
nan
t h
eif
ers
Cooke et al. (2009)
P < 0.01
****
**
Acclimation of Heifers
Cappellozza et al. (2011) – Abstract #545
Treatment x Month P = 0.02** P < 0.01
**
October November December January February March April0
10
20
30
40
50
60
70Acclimated Control
Month of the study
Pu
ber
tal,
%
**
**
Thank You!
Contact Information:Cliff Lamb
University of Florida3925 HWY 71
Marianna, FL 32446Tel: 850-394-9124
Email: [email protected]