الفهرس 
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Abstract
Data on milk productive and reproductive traits of Holstein Friesian cows were collected from two commercial dairy herds. Both herds are situated in CairoAlexandria desert road and named Green land and AlexKobenhagen Farms. Data were covered a period of 4 years, from 2000 to 2003 year. A total number of 2497 normal lactation records of 1293 cows were analyzed, of which 868 records (439 cows) for Green land farm and 1629 records (854 cows) for AlexKobenhagen farm. Results obtained revealed that, most of environmental factors affecting productive, reproductive and persistency traits were highly significant. Many of the productive and reproductive traits are characterized by wide range of values and high coefficients of variation. Heritability estimates obtained for the milk production traits and reproductive traits were moderate and similar to previous published studies. The genetic variations within these traits are sufficient to allow genetic selection for improving productive and reproductive performance of Holstein Friesian in commercial herds under Egyptian conditions. A general history of Holstein, in Egypt in the face of importation, dairy breeding development, adaptability, production and reproduction as done in present statues as well as future especially in commercial herds must have a great benefit for the future of animal production in Egypt.