estimation of genetic parameters of some productive and reproductive performance aspects in friesian cattle

34 Friesian cows records were analyzed reared at AL-Iśhagi dairy cattle station (50 km north of Baghdad) during the period 1996-2005. Heritability estimates for milk yield 305 day (MY305d), the period between calving and first estrous, services per conceptions, day open, lactation period , dry period , gestation period and calving interval were 0.17, 0.06, 0.07, 0.05, 0.07, 0.24, 0.02 and 0.03 respectively. Repeatability estimates for the same traits were 0.20, 0.12, 0.07, 0.11, 0.15, 0.15, 0.14, and 0.05 respectively. Genetic Correlation between (MY305d) and productive & reproductive traits were negative and highly significant (p>0.01(, and ranged between -0.30 and -0.73. While Phenotypic Correlation between (MY305d) and other traits were positive and high. Most Genetic and Phenotypic Correlations between studied traits except gestation period were positive and highly significant (p>0.01). Breeding Value (BV) estimated of sire for (MY305d) were ranged between 14.720 and -8.106. The highest and lowest values of Breeding Values of cows for (MY305d) were ranged between 352.224 and -159.705. Real Producing Ability (RPA) of cows for (MY305d) were predicted between 674.051 and              -365.234 as a deviation from overall mean of flock.