منابع مشابه
Relationship between individual herd-heritability estimates and sire misidentification rate.
The objectives of this study were to estimate heritabilities within herds participating in Dairy Herd Improvement and determine the relationship of the individual herd heritability with sire misidentification rate. Individual herd heritabilities for milk, fat, and protein yield and somatic cell score (SCS) were calculated with daughter-dam regression and daughter-sire predicted transmitting abi...
متن کاملSire Evaluation for Milking Duration
ACKNOWLEDGMENTS This project would not have been possible without the help of several individuals within the dairy industry. My advisor, Dr. Stan Henderson, provided the opportunity to research this project. Dr. Henderson guided me throughout the project and assisted in obtaining these data. Dr. Henderson also assisted in compiling these data and developing the manuscript. Without the help of D...
متن کاملSire Evaluation for Economic Merit
Procedures for selecting sires are compared in terms of making maximum genetic progress in economic lnerit. A quadratic index, a simplified form of the quadratic index and a linear index to evaluate economic merit, and a restricted index to improve milk as much as possible while holding milk fat percentage constant, all result in nearly equal expected genetic progress in economic merit. Selecti...
متن کاملEnvironmental correlations in sire evaluation.
Correlations were computed among averages of first lactation deviations from herdmate averages of groups of artificially sired daughters of the same Holstein bulls. The groups were constructed by specifying the time interval between animals in the different groups. Comparison of the actual correlations with the expected correlations suggests that environmental correlations are small or nil amon...
متن کاملComparison of Three Methods of Sire Evaluation
Three methods of sire evaluation were compared empirically--herdmate comparison, least squares, and maximum likelihood. Michigan Dairy Herd Improvement Association Holstein data representing 10,620 first lactation records and 1,003 herd-year groups were analyzed. Forty individual bulls representing three artificial insemination units were evaluated. The rank correlations among herdmate comparis...
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ژورنال
عنوان ژورنال: Journal of Dairy Science
سال: 1970
ISSN: 0022-0302
DOI: 10.3168/jds.s0022-0302(70)86465-7