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Characterization and usage of sexed semen from US field data. Background. AIPL mission Conduct research to discover, test, and implement improved genetic evaluation techniques for economically important traits of dairy cattle and goats
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Characterization and usage of sexed semen from US field data
Background • AIPL mission • Conduct research to discover, test, and implement improved genetic evaluation techniques for economically important traits of dairy cattle and goats • Maintain a national database to support research on genetics and management • USDA genetic evaluations • Characterize dairy industry practices
Objectives • Characterize sexed semen available and its usage from US field data • Active AI Holstein proven bulls with sexed semen marketed • Sexed semen matings for heifers and cows • Herds reporting using sexed semen
Data • Bulls with sexed semen identified using NAAB 500 series marketing code numbers • Marketing code 514 was not included as sexed semen • Inseminations with sexed semen also distinguished from breedings with conventional semen in AIPL national database, includes breeding records for both cows and heifers
Active AI Holstein Bulls • 741 active AI bulls born after January 1, 1994 • 41% (301 bulls) had sexed semen marketed as of the August 2008 USDA genetic evaluations • Mean age for bulls with sexed semen is 7.4 years compared to 8.1 years for bulls without sexed semen
Traits Evaluated • Milk • Productive life, longevity • Daughter pregnancy rate, female fertility measured by days open • Final score, type • Sire conception rate, male fertility • Calving difficulty • Lifetime Net Merit, overall economic index
Active AI Holstein bulls * Percentage of bulls with sexed semen marketed within each Net Merit Percentile
Breeding Data • Starting January 1, 2006 when 3 out of 4 Dairy Record Processing Centers (DRPC) were sending sexed semen matings through breeding records • Heifer matings • 1,544,503 total matings • 9.5% using sexed semen • Cow matings • 12,087,657 total matings • 0.4% using sexed semen
Extent of sexed semen usage • 27% of all heifers have had at least one sexed semen mating in 2008, compared to only 13% overall • 3.4% of all cows have had at least one sexed semen mating in 2008
Sex ratios • Studs with adequate number of matings achieved 91% heifer calves using sexed semen
Herds using sexed semen • 24% of all herds report using sexed semen at least once Average sexed semen use within herd by herd size
Herds using sexed semen Average sexed semen use within herd by region
Conclusions • Bulls with sexed semen available are slightly better than average active Holstein bulls • Trend show increasing usage especially in heifers since 2006, when sexed semen became commercially available • Farmers are using sexed semen when conception rates are traditionally higher, namely heifers and first service inseminations for cows
Acknowledgements • Dr. Melvin Kuhn, former AIPL researcher • Dairy Record Processing Centers (Agritech Analytics, AgSource Cooperative Services, and Dairy Records Management Systems) for providing breeding records • NAAB for developing and implementing 500 series marketing codes