the aim of the present study was to estimate the genetic parameters and genetic trends of somatic cell score (scs) in the first 3 lactations of iranian holstein cows by random regression (rr) animal model by using restricted maximum likelihood (reml) method. the data set used in this analysis included observations of 340318 test-day records of 41526 cows in 288 herds; 89969 test-day of 11750 co...

the aim of this study was to estimate the genetic trend and genetic parameters of survival traits in baluchi sheep using survival records from 27978 baluchi sheep, which were collected by the animal breeding center of iran during1979 to 2009. genetic parameters of lamb survival from 1 to 400 days of age and from 1 to the last recording date. traits were estimated using animal model (with or wit...

data related to holstein dairy cattle from 1987 to 2004 were obtained from animal breeding center of iran to estimate the genetic and phenotypic trends. variance components and genetic parameters of the first lactation records were estimated using restricted maximum likelihood method and aireml algorithm through matvec program. animal breeding values were predicted through multiple-trait animal...

genetic trend for production traits were estimated in iranian holstein cattle using the first lactation data recorded by cattle breeding and dairy product improvement center of the state from 1991 to 2006. effect of some factors on genetic trend was investigated using data from 18 large herds. (co) variance components and genetic parameters were estimated, using five trait animal model and em-a...

this study was carried out to investigate the effect of selection on the reduction of fat-tail size in lori-bakhtiari lambs. the study lasted for five years at the development and breeding center of lori-bakhtiari sheep station. estimation of fat-tail weight, using external fat-tail dimensions was obtained from regression procedure at 6 month age. soft tissue depth at the point 12 cm from the m...

Data from the slaughter of 24,001 chickens that were part of a selection program for the production of commercial broilers were used to estimate genetic trend for absolute carcass (CW), breast meat (BRW), and leg (LW) weights, and relative carcass (CY), breast meat (BRY), and leg (LY) weights. The components of (co)variance and breeding values of individuals were obtained by the restricted maxi...