the objective of this research was to estimate the genetic parameters and trend of somatic cell count in holstein cows of iran using test day records. the phenotypic the used data consisted of were consisting of 407167 first lactation test day records the which were collected by the center of animal breeding and livestock production improvement center of iran during 2009 to 2013. somatic cell c...

to estimate heritability and genetic trend for 305-d milk production and lactation persistency, a total of 130,668 monthly test day milk yields belonging to 15,183 first lactation holstein cows in 131 herds and calved from 2000 to 2009 were used. to calculate 305-d milk yield as well as lactation persistency, estimated parameters of wilmink’s exponential function were applied. the parameters of...

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 ...

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...

T domestic goat (Capra hircus) often is dismissed as the ‘‘poor man’s cow’’ for its ability to thrive on meager fodder and cope with harsh environments. However, this belies the economic and archaeological importance of the species. From an agricultural standpoint, the world’s 700 million goats provide reliable access to meat, milk, skins, and fiber for small farmers—particularly in developing ...