1
|
|
2
|
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3
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- 40,849 herd-years from 2000-2003
- Herds continuing on test
- ³80%
test-day records passing edits
- ³10 test
days
- 33% of cows in milk with final record reported during the herd year
- Termination code (TC) 3-7 reported for 1,043,055 cows
- No disposal information reported for ~20% of final records
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4
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5
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- 8.5 million final lactation records since 1997
- 2.8 million likely in progress
- Calving in 2004 or 2005
- TC not 3-7
- 0.5 million sold for dairy (TC 2)
- To herds not participating in DHIA testing
- 4.0 million include disposal code (TC 3-7)
- 1.2 million unknown disposition
- Herd discontinued DHIA testing (and TC 2 not used)
- Disposal not recorded or ambiguous
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6
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7
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- Terminal lactation records (3,138,918)
- Lactations 1-5
- Ending 1998 through 2004
- TC 3-7
- Paired with herd-year averages for the year culled
- Milk
- Fat
- Protein
- SCS and SCC
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8
|
- Difference from herd average (HA) for milk, fat, and protein included TC
(3 vs. other)
- Difference from HA for SCS and SCC included TC (7 vs. other)
- Days open included TC (4 vs. other) and was restricted to cows with
>50 DIM
- All included lactation number, termination year and interactions with TC
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9
|
- Cows with TC 3 had milk yield 2% and protein yield 3% lower than HA
- Significantly different from other culled cows with milk yield 5% and
protein yield 2% higher than HA
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10
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- Cows with TC 7 had SCS 21% higher than HA
- Significantly different from other culled cows, although those cows also
had SCS higher (4%) than HA
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11
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- Cows with TC 4 had significantly higher days open (258) than other
culled cows with at least 50 DIM (173 days open)
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12
|
- The most common reported reasons for culling cows in 1st
lactation were low production (TC 3) and reproductive problems (TC 4)
- The most common reported reason for culling cows in 3rd or
later lactation was high SCC/mastitis (TC 7)
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13
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- Most terminal records include an indication cow status (live/dead)
- Most records for culled cows include an indication of cause
- Reported TC are supported by cow and herd records
- Research aimed at using TC information to improve trait analysis is
warranted
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