|DECHOW, C - PENN STATE UNIVERSITY
|ZWALD, N - PENN STATE UNIVERSITY
Submitted to: Journal of Dairy Science
Publication Type: Abstract Only
Publication Acceptance Date: 3/8/2007
Publication Date: 7/8/2007
Citation: Dechow, C.D., Norman, H.D., Zwald, N.R. 2007. Relationship of herd-heritability with sire misidentification and entry into a proven sire lineup. Journal of Dairy Science. 90(Suppl. 1):262(abstr. T66).
Technical Abstract: The objectives of this study were to estimate the relationship of individual herd heritability with sire misidentification rate and the likelihood of a sire entering an active sire lineup after progeny testing. Milk, fat and protein yield and somatic cell score (SCS) were provided by the Animal Improvement Programs Laboratory at USDA. Paternity verification results from DNA marker analysis were provided by Alta Genetics, Inc. for 145 herds. The number of cows tested per herd ranged from 5 to 274. Herd heritability was calculated with daughter-dam regression and daughter-sire predicted transmitting ability (PTA) regression using 6,848,885 records from 17,608 herds. Herd heritabilities were estimated with regression models in AS-Reml that included fixed breed, age within parity, herd-year-season of calving, dam records nested within state, and sire PTA within state; random regression coefficients were dam records and sire PTA within herd. Average daughter-dam herd heritability estimates ranged from 0.26 (SCS) to 0.41 (fat yield), whereas daughter-sire herd heritability ranged from 0.11 for SCS to 0.20 for fat yield. Correlations between herd heritability and sire misidentification rate ranged from -0.23 to -0.43. The correlation between a principal component for all measures of herd heritability and sire misidentification rate was -0.45. Sires that were proven in low heritability herds were less likely to enter a proven sire lineup than sires proven in average to high heritability herds. Individual herd heritabilities can be generated with simple regression techniques for several thousand herds simultaneously. The herd heritability estimates could be used to identify herds that might provide inaccurate data for progeny testing, and could be used to identify sires with potentially underestimated genetic evaluations.