_______________________________________________________________________________________ Abstract Selection accuracy for resistance to mastitis may be increased by combining somatic cell score (SCS) and udder type into an udder health index, using genetic parameter estimates among them. A multi-trait animal model was used to estimate genetic parameters among lactation average SCS and udder type ...

The objective of this study was to evaluate genetic and phenotypic parameters for some reproductive traits of Black Bengal does. Genetic parameters were estimated by Residual Maximum Likelihood procedure, fitting an animal model ignoring maternal genetic or permanent environmental effects. The least-squares means of litter size at birth (LSB), litter size at weaning (LSW), litter weight at birt...

The objective of the present study was to estimate genetic trends for lactation milk yield, persistency of milk yield, somatic cell count and interval between first and second calving in Holstein dairy cows of Iran. The dataset consisted of 210,625 test day and 25,883 first parity cows with milk yield recorded from July 2002 to September 2007 comprising 97 herds in Iran. Breeding values of anim...

First lactation milk, fat, and protein yields for first lactations of 8044 Holstein cows in New York from 24 herds were used to estimate genetic and phenotypic covariances with an animal model by restricted maximum likelihood. Numerator relationships within herd, including those from sires, were utilized, although relationships across herds were ignored. Each analysis was terminated after 300 r...

the present study was conducted to estimate genetic parameters and genetic, environmental and phenotypic trends of milk production traits in holstein cattle of hamedan province. in this study 11986 305-d records of first three parities of hamedan province holstein cattle, which were gathered during 1990-2011, were used. variance-covariance components and breeding values were estimated using ani...

a data file containing 607662 (317608) milk (open days) records belonging 294417 (177838) holstein cows that were calved from 1983 to 2008 was used. the bivariate repeatability model was used for data analyzing so that herd, calving year, calving month, days in milk (only for milk trait) and calving age for each parity, were assumed as fixed effects and additive genetics and permanent environme...