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* Animal Improvement Programs Laboratory,
Agricultural Research Service, USDA, Beltsville, MD 20705-2350 Department of
Dairy Science, University of Wisconsin-Madison, Madison 53706
1 Corresponding author: duane.norman{at}ars.usda.gov
In August 2007, the USDA changed from calculating official
genetic evaluations quarterly to triannually in conjunction with
the schedule change for international evaluations. To offset
part of the delay in providing genetic information because of
the reduced frequency of official evaluations, industry
cooperators requested that interim evaluations be initiated for
progeny-test (PT) bulls based on first-lactation records from PT
daughters and their contemporaries that calved recently in
cooperator herds. Alternatives for interim evaluations were studied
to determine which would characterize genetic merit of PT bulls
most accurately. Four alternative Holstein data sources were
examined based on maximum data interval (most recent 12 or 18
mo of first calvings) and minimum number of PT daughters in
herd (1 or
5). The highest correlation between
August 2006 interim and official evaluations for milk yield was 0.980
for interim evaluations based on the most recent 18 mo of first
calvings from cooperator herds with
1 PT daughter. That high
correlation confirmed that interim evaluations based on limited
data could provide genetic estimates of value between official
evaluations. With the support of the Council on Dairy Cattle
Breeding, the USDA initiated 3 interim evaluations each year
with release limited to PT bulls with
10 daughters and an increase
in reliability since the most recent official evaluation.
Key Words: interim evaluation • progeny test • daughter performance
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