effect of synchronization protocols on days open and pregnancy rate at 120 days in dairy cattle
DESCRIPTION
Effect of Synchronization Protocols on Days Open and Pregnancy Rate at 120 Days in Dairy Cattle. Reproductive Performance. History Decreasing performance over time Negative correlation with production traits Poor performance costly to producers Use of synchronization protocol - PowerPoint PPT PresentationTRANSCRIPT
R. C. Goodling*1,2, G. E. Shook1, K. A. Weigel1, N. R. Zwald1, R. D. Welper3
1University of Wisconsin, Madison, WI2Current Address: Animal Improvement Programs LaboratoryAgricultural Research Service, USDA, Beltsville, [email protected] Genetics, Watertown, WI
Effect of Synchronization Protocols on Days Open and Pregnancy Rate
at 120 Days in Dairy Cattle
ADSA-ASAS Joint Meeting 2004 (2) R. C. Goodling
Reproductive Performance History
Decreasing performance over time Negative correlation with production
traits Poor performance costly to producers
Use of synchronization protocol Numerous protocols available Dependent upon herd Variety of herd applications
ADSA-ASAS Joint Meeting 2004 (3) R. C. Goodling
Objectives Determine effects of synchronization
protocols on genetic parameter estimates for: Days open (DO) Pregnancy rate at 120 days (PR120)
Evaluate best approach to analyze reproduction field data with synchronization
ADSA-ASAS Joint Meeting 2004 (4) R. C. Goodling
Traits Days open (DO)
Includes interval from calving to first breeding (DFB) and the interval from breeding to conception
Current selection on related trait (DPR) Handles cows that do not breed back
Pregnancy rate at 120 d (PR120) Categorical trait Reflects 13 month calving interval Available before DO, less censoring
ADSA-ASAS Joint Meeting 2004 (5) R. C. Goodling
Data Collection 64 herds on progeny testing program
Utilized Dairy Comp 305 herd software 50% sire identification and 75% breeding
information Data requirements:
Recorded fresh event First complete lactation (max. 6th) DFB between 37 d and 300 d DO between 37 d and 500 d Calving year between 1999 and 2002
ADSA-ASAS Joint Meeting 2004 (6) R. C. Goodling
Models Sire models for both traits Base Model
Fixed effects: lactation, age at freshening (months), herd-year-season
Random effects: sire and residual Expanded Model
Base model plus fixed effect for synchronization
Interaction Model Expanded model plus random effect for sire-
by-herd management interaction
ADSA-ASAS Joint Meeting 2004 (7) R. C. Goodling
Data Analysis 2 classifications investigated
Complete data set with various models Herd Management Category
Estimation Methods DO: Gibbsf90 to create posterior
distribution Median and SD among iterations
PR120: Probit.f90 threshold program Mean and SD among iterations
ADSA-ASAS Joint Meeting 2004 (8) R. C. Goodling
Herd Management Categories Herds classified by:
Level of synchronization use Herd DFB standard deviation
Three categories: STH- standing heat herds
Average 19% synch, 30.1 DFB SD TAI- timed breeding herds
Average 81% synch, 13.7 DFB SD MIXED- mixed management herds
ADSA-ASAS Joint Meeting 2004 (9) R. C. Goodling
TAI Herd: 1st Breedings
0
75
150
225
300
10/1/2000 4/19/2001 11/5/2001 5/24/2002 12/10/2002Breeding Date
Day
s in
Milk
1st-SYNCH
1st-NONE
ADSA-ASAS Joint Meeting 2004 (10) R. C. Goodling
TAI Herd: 1st & 2nd Breedings
0
75
150
225
300
10/1/2000 4/19/2001 11/5/2001 5/24/2002 12/10/2002Breeding Date
Day
s in
Milk
1st-SYNCH
1st-NONE
2nd-SYNCH
2nd-NONE
ADSA-ASAS Joint Meeting 2004 (11) R. C. Goodling
STH Herd: 1st Breedings
0
75
150
225
300
10/1/2000 4/19/2001 11/5/2001 5/24/2002 12/10/2002Breeding Date
Day
s in
Milk
1st-SYNCH
1st-NONE
ADSA-ASAS Joint Meeting 2004 (12) R. C. Goodling
STH Herd: 1st & 2nd Breedings
0
75
150
225
300
10/1/2000 4/19/2001 11/5/2001 5/24/2002 12/10/2002Breeding Date
Day
s in
Milk
1st-SYNCH
1st-NONE
2nd-SYNCH
2nd-NONE
ADSA-ASAS Joint Meeting 2004 (13) R. C. Goodling
Mixed Herd: 1st Breedings
0
75
150
225
300
10/1/2000 4/19/2001 11/5/2001 5/24/2002 12/10/2002Breeding Date
Day
s in
Milk
1st-SYNCH
1st-NONE
ADSA-ASAS Joint Meeting 2004 (14) R. C. Goodling
Mixed Herd: 1st & 2nd Breedings
0
75
150
225
300
10/1/2000 4/19/2001 11/5/2001 5/24/2002 12/10/2002Breeding Date
Day
s in
Milk
1st-SYNCH
1st-NONE
2nd-SYNCH
2nd-NONE
ADSA-ASAS Joint Meeting 2004 (15) R. C. Goodling
Herd Management Category:Median DO and Mean PR120
0
50
100
150
Timedbreeding
Mixed herd Standingheat
Day
s op
en
0
10
20
30
40
50
60
Per
cent
preg
nan
t at
120 d
(%
)
DO PR120
ADSA-ASAS Joint Meeting 2004 (16) R. C. Goodling
Variance & Heritability: DO
Model σ2s σ2
r h2
Base 80.7 7446 0.04
Expanded 54.2 6638 0.04
Interaction* 46.4 6633 0.03
*Variance for sire-by-herd management interaction was 12.6.
ADSA-ASAS Joint Meeting 2004 (17) R. C. Goodling
Variance & Heritability: PR120
Model σ2s h2
Base 0.029 0.11
Expanded 0.028 0.11
Interaction* 0.025 0.10
*Variance for sire-by-herd management interaction was 0.021.
ADSA-ASAS Joint Meeting 2004 (18) R. C. Goodling
Variance & Heritability: Data Subsets
Herd Management Category Lower variance estimates for timed
breeding herds Larger sire and animal variance and h2
for standing heat herds Variances for mixed herds were
intermediate
ADSA-ASAS Joint Meeting 2004 (19) R. C. Goodling
Conclusions
Effect of synchronization on parameters Reduced residual variance Slight reduction in sire and residual
variances Negligible effect on heritability
Account for differences in protocol Detection of estrus vs. timed breeding Account for each protocol individually Herd application of protocols
(Uniform vs. select)