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Disposal reporting and disposition of culled cows by parity and herd size. DHIA Termination Codes (TC). Herd Disposal Reporting. 40,849 herd-years from 2000 2003 Herds continuing on test 80% test-day records passing edits 10 test days
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Disposal reporting and disposition of culled cows by parity and herd size
Herd Disposal Reporting • 40,849 herd-years from 20002003 Herds continuing on test 80% test-day records passing edits 10 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
Cow Disposal Reporting • 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
Data • 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
Models • 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
Yield Results • 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
SCS Results • 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
Reproduction Results • Cows with TC 4 had significantly higher days open (258) than other culled cows with at least 50 DIM (173 days open)
Disposal by Parity • 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)
Conclusions • 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