genetic parameters were estimated for somatic cell score (scs) in dairy cattle of iran using test day records. the records of first lactation were extracted from the database of national animal breeding center for cows calved between 2001 and 2010. data included 222923 test-day records, obtained from 29668 animals distributed in 100 different herds. estimates were carried out through gibbs samp...

Calving records from the Animal Breeding Center of Iran collected from January 1990 to December 2007 and comprising 207 106 first calving events of Holsteins from 2 506 herds were analysed using linear sire models to estimate genetic trends for age at first calving (AFC) and milk traits. Genetic trends were obtained by regressing yearly mean estimates of breeding values on year of birth. In gen...

Productive and reproductive traits have great importance in international dairy cattle breeding objectives. Production, reproduction (days open and calving interval) and pedigree data of Iranian Holstein dairy cattles were collected between 2002 and 2012 from 47 herds in Isfahan province. The data set consisted of 30179 records from 18837 registered IranianHolstein dairy cattles. Single trait r...

the purpose of this study was to describe the association between grain yield and its components. the experiment was conducted in a randomized complete block design with three replicatsions. results of analysis showed that similar trends were observed for genotypic and phenotypic correlations and in most cases, the value for genetic correlation was greater than phenotypic value. 100-seed weight...