Genetic Parameter Estimates of Advanced Registry Holstein Cows in Japan

Genetic Parameter Estimates for Lactation Curve Parameters, Milk Yield, Age at First Calving, Calving Interval and Somatic Cell Count in Holstein Cows

The objective of this study was to estimates the genetic and environmental components for the lactation curve parameters, milk yield, age at first calving (AFC), calving interval (CI) and somatic cell count (SCC) in Iranian Holstein cows. The dataset consisted of 210625 test day records from 25883 cows with milk yield in the first parity recorded from July 2002 to September 2007 in a total of 9...

Estimates of Genetic and Phenotypic Parameters for Milk Production in Moroccan Holstein-Friesian Cows

To satisfy the growing demand of the human population for milk, the Moroccan government set up a plan in 1975 to increase milk production. The most important genetic strategies were the introduction of improved dairy cattle, the institution of milk recording, and the extension of artificial insemination (AI). Thus, more than 10,000 Holstein and Friesian heifers were purchased annually from Euro...

Genetic parameter estimates of body weight traits in Iran-Black sheep

The objective of the current study was to estimate the genetic parameters for body weight traits at different ages in Iran-Black sheep. Data collected during a 24-year period (1984-2008) on body weight were used to model the growth trajectory and estimate genetic parameters. Studied traits were birth weight (BW), weaning weight at 3 months of age (WW), 6 months weight (6MW), 9 months weight (9M...

Estimation of Genetic Parameters for Lactation Curve Traits in Holstein Dairy Cows in Iran

The objectives were to estimate (co)variance components and genetic parameters for lactation curve traits in Holstein dairy cows in Iran. The used data were records on Holstein cows collected during January 2003 to December 2012 by the Animal Breeding Center of Iran (Karaj, Iran). In order to describe the lactation curve, an incomplete gamma function was fitted to 691200 test-day records on 962...

Genetic Regulation of Feed Efficiency in Lactating Holstein Cows