to test the effect of culling herd life from the breeding goal function, 4 different selection indices were established as: index 1: using milk production (milk), fat percentage of milk (fat%) and rear udder height (ruh); index 2: using milk , fat% and fore teat placement (ftp), index 3: using milk, fat% and fore udder attachment (fua); and index 4: using milk, fat%, ruh, ftp and fua) under two...

The aim of this study was to define breeding goals and determine the suitable selection index in Rayeni cashmere goat using simulated data. To select animals for increased quantity of meat, milk and cashmere produced, body weight of the doe (BWD), milk weight (MW), cashmere weight (CW), weight of kids for sale (WK) and number of kids for sale per doe (NK) was used as selection criteria. Four se...

Two selection goals of inclusion or exclusion of calving interval (CI) in the selection goal function for Holstein cows in Iran, besides milk yield, milk fat percentage, and milk protein percentage, were studied. Four selection indices were composed of using the information on production traits, CI and / or days from calving to first insemination (DFI). The results of the predicted genetic grow...

Body condition score (BCS) is a useful tool in assessing the energy status of dairy cattle. Previous research has shown that it is heritable and genetically correlated to reproductive performance. Currently, interest exists in developing selection indexes for fertility that include BCS information. Before such indexes are developed, it is important to assess the genetic covariance between BCS a...

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...

genetic and phenotypic parameters related to production traits, udder conformation and somatic cell count for the iranian holstein cows were estimated. monthly records of somatic cell counts (scc) were primarily transformed into somatic cell scores (scs) and the the average level of lactation period, with correction for milk volume, was calculated. by use of these estimates an udder health inde...

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...