Sire Evaluation for Economic Merit

Sire 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...

Sire 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...

Selection of Dairy Cows for Economic Merit

Selection of dairy cows for economie merit requires the use of a model for genetic merit that involves the cross-product of the genetic values for milk and milk fa t percentage. A linear and a quadratic index are described as procedures for selection of cows, the linear index being blp.~ + bzp, and the quadratic index being blp,~ + b~_pt + b~p,n 2 + b~p, ~ + b~p.,pt where p~ and pt are the phen...

Environmental 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...

Report on Economic Basis for a Nordic Total Merit Index