The aim of this study was to refine the position of previously detected quantitative trait loci (QTL) on bovine chromosome 14 affecting milk production traits, using both linkage analysis (LA) and combined disequilibrium and linkage analysis (LDLA) methods, in Iranian Holstein dairy cattle. Analysis data was LRT (likelihood ratio test) and computed using the DMU (estimate the (co)variance compo...

Buffalo milk has excellent physical and chemical qualities as a consequence of the high percentage of constituents. This milk property is desirable for the dairy industry because it facilitates manufacture of mozzarella cheese. We estimated genetic parameters for milk yield, milk fat and protein and their effects on mozzarella cheese production using Bayesian inference. Using information from 4...

Milk yield records from 1st to 5th lactations of Iranian Holstein cows were analyzed using repeatability and a number of multivariate models that varied in additive genetic variance structure. A total of313,006 milk yield records were used. The records were obtained from 116,531 cows born between 2001 and 2005. The animals originated from 2,355 sires and 91,212 dams. A multivariate model with h...

INTRODUCTION The discovery of the deep freezing method of cattle semen preservation allowed for a worldwide exchange of genetic material and that the importation of semen from improved breeds have been often used in attempts to increase local livestock productivity. Frequently, this has been done without systematic evaluation of the introduced stocks in the new environment. In 1998, Argentina s...

introduction milk solid no-fat is economically very important in cheese industry. compared to the other kinds of milk, ewe’s milk contains higher amount of milk solids no-fat. milk solids no-fat (msnf) contains lactose, caseins, whey proteins, and minerals. the use of test day records in random regression method has several benefits including flexibility to account for the environmental and gen...

The objectives of this study were to estimate from test day records the genetic and environmental (co)variance components, correlations, and breeding values to increase genetic gain in milk yield of Lucerna and US Holstein cattle. The effects of repeated observations (within cow) were explained by first-order autoregressive processes within and across lactations using an animal model. Estimates...

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...