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Vitor Mercadante, Virgina Tech Aug. 20, 2019
2019 ARSBC, Knoxville, Tenn. 1
Characteristics of Successful
Reproductive Management
Programs Vitor R. G. Mercadante
Department of Animal and Poultry Sciences
Department of Large AnimalClinical Sciences
Maximize pregnancy rate early in the
breeding season and develop/select
replacement heifers that are highly fertile
at the lowest cost possible
Reproductive Efficiency
Management
Selection pressure
Nutrition
Reproductive technologies
Reproductive Efficiency=+++
65 59 51 60 51 48 57 55
92 89 82 90 9078
91 86
0102030405060708090
100
1 2 3 4 5 6 7 8
Preg
nanc
y ra
te, %
Location
TAIFinal
Reproductive Efficiency
VDOC Fall 2018 Pregnancy Rates
Number one factor affecting management?
THE MANAGER!
Management
• Needs to care OPEN…
Vitor Mercadante, Virgina Tech Aug. 20, 2019
2019 ARSBC, Knoxville, Tenn. 2
PREGNANT! Number one factor affecting management?
THE MANAGER!
Management
• Needs to care• Details matter
Management
• Postpartum anestrus• Suckling stimulus• Age• Genetics• Nutrition• Body weight
• Body condition score• Reproductive
management• Plane of nutrition• Body composition• Animal handling
• Factors Affecting Fertility in Beef Females
AI Success0.90
0.90
0.90
0.90
=
x
x
x
65%
AI Success0.80
0.80
0.80
0.80
=
x
x
x
41%
• Build partnerships
Management
• Other cattlemen• Extension• Veterinarian
Vitor Mercadante, Virgina Tech Aug. 20, 2019
2019 ARSBC, Knoxville, Tenn. 3
Number one factor affecting management?
THE MANAGER!
Management
• Needs to care• Details matter • Partnerships• Data driven decisions
Record Keeping• Dam ID – sire information• Date of birth• Birth weight• Weaning weight• BCS at calving and breeding• Health records• Temperament• Breeding
Management
Accurate Records
Management
Management
Selection pressure
Nutrition
Reproductive technologies
Reproductive Efficiency=+++
Selection Pressure• Must calve by 24 months of age• Cow must have a calf every 365 days• Cow must calve without assistance• Calf must be genetically capable to perform• Cow must provide sufficient resources for the
calf to reach it’s genetic potential• Cows must maintain their body condition
score for management conditions• Must not be crazy!
Management Selection Pressure
26.2
12.7
21.9
16.8
22.422.8
15.5
23.5
18.220.0
0
10
20
30
40
< 64 64 to 84 85 to 105 106 to 149 > 149
%
Length of breeding season, days
Operations Cows
• Breeding Season
(NAHMS, 2008)
61%
Vitor Mercadante, Virgina Tech Aug. 20, 2019
2019 ARSBC, Knoxville, Tenn. 4
Selection Pressure
(Cushman et al., 2012)
• Influence of Calving Period on Weaning Weights
5 calves
(Cushman et al., 2012)
Selection Pressure• Influence of Calving Period on Reproductive Longevity
Pregnancy Diagnosis
Management
Nutrition
Selection pressure
Reproductive technologies
=+++
Reproductive Efficiency
Culling Open Cows!!
Pregnancy Diagnosis
10.8
25.8
41.2
58.3
18.0
0
10
20
30
40
50
60
70
80
1 to 49 50 to 99 100 to 199 > 200 All Operatio ns
%
Herd Size
(NAHMS, 2008)
Breeding Soundness Exam
10.9
33.2
45.9
56.8
19.5
0
10
20
30
40
50
60
70
80
1 to 49 50 to 99 100 to 199 > 200 All Operatio ns
%
Herd Size
(NAHMS, 2008)
Cow and Heifer job description• Must calve by 24 months of age• Cow must have a calf every 365 days• Cow must calve without assistance• Calf must be genetically capable to perform• Cow must provide sufficient resources for the
calf to reach it’s genetic potential• Cows must maintain their body condition
score for management conditions• Must not be crazy!
Selection Pressure
Vitor Mercadante, Virgina Tech Aug. 20, 2019
2019 ARSBC, Knoxville, Tenn. 5
Temperament and Fertility
(Dias et al., 2018)
Bos taurus beef heifers in VA
91
6577 71
935
23 29
0
2040
6080
100
Glade Southampton VT Overall
Heife
rs, %
Location
Temperament by LocationCalm Excitable
Temperament and Fertility
(Dias et al., 2018)
Bos taurus beef heifers in VA
5536
0
10
20
30
40
50
60
70
Calm Excitab le
Preg
nanc
y rat
e, %
Temperament
TAI Pregnancy rate by TemperamentTemperament P = 0.042Location P = 0.235Temp*Loc P = 0.364
Temperament and Fertility
(Cooke et al., 2012)
Bos taurus beef cows
Management
Selection pressure
Nutrition
Reproductive technologies
Reproductive Efficiency=+++
Nutrition, Nutrition, Nutrition!!
BCS 5
BCS 3
BCS 7
Factors Affecting TAI pregnancy rate
(Stevenson et al., 2015)
Parity Days postpartum Body condition score n Pregnancy rate
Multiparous > 72 > 5 2,154 51.7x
> 72 ≤ 5 2,054 43.8y
≤ 72 > 5 1,056 44.2y
≤ 72 ≤ 5 1,676 41.8y
Primiparous > 72 > 5 496 43.8x
> 72 ≤ 5 623 43.5x
≤ 72 > 5 166 40.7xy
≤ 72 ≤ 5 284 33.3yxy Within parity, means without a common superscript differ (P < 0.05)
Vitor Mercadante, Virgina Tech Aug. 20, 2019
2019 ARSBC, Knoxville, Tenn. 6
Management
Selection pressure
Nutrition
Reproductive technologies
Reproductive Efficiency=+++
Reproductive Technologies• Breeding season management• Breeding soundness exam• Pregnancy diagnosis• Early weaning• Culling open females• Crossbreeding• Artificial insemination • Estrus synchronization • Fixed-time AI • Embryo transfer • In vitro fertilization – IVF• Somatic cell nuclear cloning• Transgenic technologies
Estrous Synchronization• Pharmacological control of the estrous cycle
• Advantages of Fixed-Timed Artificial Insemination - TAI• Induction of cyclicity• No heat detection• Optimization of labor • Increase proportion of females exposed to AI• More females pregnant to AI in a shorter period
Why folks choose not to TAI?
“PREGNANCY RATES TO TAI ARE TOO LOW…”“Too many hassle factors…”
• 40-60% pregnancy rates to TAI• It is a process that will take time
and commitment!
• 1,700 cows on 8 operations
TAI in South Dakota TAI Pregnancy Rates by Herd
56.962.1
45.2
65.8
44.450.4
45.2 48.5
0
10
20
30
40
50
60
70
80
1 2 3 4 5 6 7 8
Preg
nanc
y rat
e, %
Herd
Using TAI for the first time
Vitor Mercadante, Virgina Tech Aug. 20, 2019
2019 ARSBC, Knoxville, Tenn. 7
TAI Pregnancy Rates by Herd
56.962.1
45.2
65.8
44.450.4
45.248.5
0
10
20
30
40
50
60
70
80
1 2 3 4 5 6 7 8
Preg
nanc
y rat
e, %
Herd
Using TAI for at least 5 years
Distribution of Days Postpartum
0
5
10
15
20
25
34 44 54 64 74 84 94 104 114 124
%
Days postpartum
Standard deviation:Herd 5 – 16.9 days
• HERD 5 – 44.4% PR, TAI FOR THE FIRST TIME
Distribution of Days Postpartum
0
5
10
15
20
25
34 44 54 64 74 84 94 104 114 124
%
Days postpartum
• HERD 4 – 65.8% PR, TAI FOR 7 YEARS
Standard deviation:Herd 4 – 5.6 days
Number one factor affecting management?
THE MANAGER!
Management
• Needs to care• Details matter • Data driven decisions• Focused on long term benefits
Impact of TAI on Calvingand Weaning
20.923.2
16.417.5
4.63 2.7
1.5
6.7
17.7
28.7
25.2
7.8
1.8 2.8 1.8
0
10
20
30
40
1- 10 11 -2 0 21 -3 0 31 -4 0 41 -5 0 51 -6 0 61 -7 0 >70
% o
f cal
ves b
orn
TAI
Control44.1%
vs.24.7%
(Rodgers et al., 2012)
Impact of TAI on Calvingand Weaning
(Rodgers et al., 2012)
Treatment
Item Control TAI
No. of cows 615 582
Weaning rate, % 78 84
Weaning weight, lb 387 ± 8a 425 ± 8b
ab Means within row differ (P < 0.01) 38 lbs
$69/cow
Vitor Mercadante, Virgina Tech Aug. 20, 2019
2019 ARSBC, Knoxville, Tenn. 8
Managing Reproductive Efficiency
YOU DECIDE WHEN YOUR COWS GET PREGNANT!!
• Maximize cows exposed to AI• Maximize pregnancy rate• More cows pregnant earlier• More calves born earlier• More pounds of calf weaned
Contact Information
Vitor R.G. Mercadante
540-231-9153
@vitormercadante