in this research, 272977 test day records collected from 659 herds during years 2001 to 2011 by the iranian animal breeding center were used. in the first section the ability of different models to predict daily milk yield from alternative milk recording was tested. the result showed that a complex model including noon milking time plus the effect of lactation curve of ali and schaeffer functio...

adjusted milk yield for 305 days and two milking times along with actual first lactation records of 187138 holstein cows were used to find out the effect of record adjustment on variance components estimation and on genetic evaluation. records had been gathered by the animal breeding center of iran during years 1991 to 2006. the pedigree file included 288032 animals. a single animal model with ...

Dairy cattle breeding programs have been based in the selection for traits related to milk production. In this research a data set of 63 herds of East Azerbaijan province Holstein cattle, collected during 2002-2013 by the Iranian Animal Breeding Center was used to estimate the repeatability and heritability of three traits of economic importance. Genetic parameters for first three lactations of...

In this research, 272977 test day records collected from 659 herds during years 2001 to 2011 by the Iranian animal breeding center were used. In the first section the ability of different models to predict daily milk yield from alternative milk recording was tested. The result showed that a complex model including noon milking time plus the effect of lactation curve of Ali and Schaeffer functio...

u sing the database of the animal breeding center ofiran and based on the eligible test-day data from 78969 cows in five provinces: tehran (with 44129 cows), ghazvin (6668), zanjan (1767), isfahan (7572), khorasan-e-razavi (14521) and others (4312) the averages of 426850 ± 966840 and 473860 ± 605330 cells/ml of milk somatic cell count (scc) was calculated for individual cows and herds respectiv...