The main objective of this study was to estimate the genetic parameters for multi-trait evaluation of birth weight (BW), gestation length (GL) and calving difficulty (CD) in first-parity Iranian Holstein dairy cattle. The data included 29,950 calving records collected during 1995 to 2014 by the Animal Breeding and Improvement Center of Iran. A threshold-linear sire-maternal grandsire model was ...

Data from 522 lambs of the Timahdit breed representing 13 sires were used to estimate genetic parameters. Traits analyzed were weights at birth (BW), 30 days (W30), 70 days (W70) and 90 days (W90), average daily gains from 10 to 30 days (ADG10-30), 30-70 days (ADG30-70) and 30-90 days (ADG30-90). REML estimates of variance and covariance components were obtained assuming animal models that incl...

objective: estimation of genetic parameters for kleiber ratio (kr) and genetic trends for pre-weaning weights of arabi sheep has not been previously conducted.methods: data and pedigree information were collected at the khuzestan ramin agricultural and natural resources university, animal science research station, located in southwest iran, from 2001 to 2008. (co)variance components and corresp...

in this study records of 15723, 12108 and 5236 zel sheep for birth weight (bw), weaning weight (ww) and 6-month weight (6mw) traits were used. data has been collected by the jahad-e-keshavarzi organization of province of mazandaran during 1994-2009. the heritability of direct and maternal of growth traits was estimated using the univariate analysis with restricted maximum likelihood (reml). in ...

introduction lamb production is the largest part of income in sheep industry. therefore, the mortality rate of lambs is a key factor in profit of the sheep breeding. mortality rate of lambs (or lamb mortality rate) in different breeds of sheep under different climatic conditions is varying from 15% to 50% and an average of 9% to 20% has been reported. survival rate is a combination trait that i...

the aims of this research were to estimate of genetic parameters for pre-weaning traits and lamb survival in iran-black sheep. for this purpose 6344 records for birth weight (bw) and lamb survival (ls) and 5264 records for weaning weight (ww), average daily gain (adg) and kleiber ratio (kr) were available, which collected by abbasabad animal breeding and rearing station, over the period from 19...

influence of maternal and sire-generation interaction effects on day-old chick' weight was investigated in two commercial broiler sire and dam lines, and in mazandaran native fowls. the data were analysed through restricted maximum likelihood (reml) procedures, using asreml software. ten different animal models were implemented and compared with likelihood ratio test. all models consisted ...

a total of 2000 records of egg quality of 746 birds and body weight data from 17th generation of fars native fowl breeding station were used to estimate the genetic parameters of egg quality and body weight traits. six univariate animal models with different random effects were fitted for each trait. a model with direct additive genetic and maternal permanent environmental effects was the most ...

the main objective of this study was to estimate the genetic parameters for multi-trait evaluation of birth weight (bw), gestation length (gl) and calving difficulty (cd) in first-parity iranian holstein dairy cattle. the data included 29,950 calving records collected during 1995 to 2014 by the animal breeding and improvement center of iran. a threshold-linear sire-maternal grandsire model was ...