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Quality of Data Included in Genetic Evaluations for Daughter Pregnancy Rate. Evaluation Methods. BLUP Animal Model Same programs used for yield, PL, SCS Adjust for regional, seasonal and parity differences. Convert to preg rate = (233-DO) / 4.
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Quality of Data Included in Genetic Evaluations for Daughter Pregnancy Rate
Evaluation Methods • BLUP Animal Model • Same programs used for yield, PL, SCS • Adjust for regional, seasonal and parity differences. • Convert to preg rate = (233-DO) / 4
Average breed effects across regions and time by calving month
Pregnancy Rate Evaluation Data Sources • Days open reported, verified calving interval. • No calving interval, days open reported. • No breeding date reported, next calf. • No breeding reported, no next calf. • Sold for reproductive reasons, days open set to 250. • Pregnancy verification codes have been available since 2002.
Pregnancy Rate Evaluation • Records considered complete at 250 DIM • Lower limit set to 50 DO • 5% of records • Upper limit set to 250 DO • 14% of records
May 2003 Evaluation • Holstein data from May 2003 evaluation • 40 million lactations • 16 million cows • Example evaluations: • Data for recent, well-sampled bulls • Actual bull evaluations
Future Directions Pregnancy rate will be included in Net Merit. Fertility records will be used earlier in lactation. DPR can be used in multi-trait PL. Fertility database and formats will be improved.
Format 5 - Reproductive Records • Animal ID, sire ID, dam ID, X-ref ID • Animal herd code information • Reproductive segments: • Date of event, code for actual or estimated date • Includes many events, service sire ID
Format 5 - Reproductive Event Codes • H Observed in estrus (heat) but not inseminated • S Synchronized estrus event (injection or other methods) • A Artificial insemination • N Natural service breeding • E Embryo donation
Format 5 - Reproductive Event Codes . . . • I Embryo implantation • P Confirmed pregnant • O Confirmed not pregnant (open) • X Cow given a “do not breed” designation • D Delete event(s) for this “date of event”
Format 5 in the Future: • Separate estrus expression and conception rate (female fertility) • Service sire fertility (male fertility) • Keep track of ALL service sires, number and type of services, not just the most recent
Conclusions • Most herds are reporting accurate breeding dates. • Records currently used only if complete (250 DIM). • More reproductive events will be obtained in the future. • More accurate and complete data will provide better fertility evaluations for farmers and industry.
Acknowledgments • All DHIA herds and processing centers contributed data • Lillian Bacheller for work on improving the fertility database • John Clay suggested expressing cow fertility as pregnancy rate