الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Milk production records of imported pregnant Friesian heifers
from Holland during 1978, 1982 and 1984 which represented the first
generation, (grand mothers) in additloo to their daughters second
generation (mothers) as well as the third genefatlon (daughters) which
were locally borned and, raised in Abo-Grida Experimental Farm,
belonging to the Holland Company for Milk Production, Egypt were used
in the present study.51OOy_ in Ihis respect,the experimental animals were
classified on the basis of origin into Iwo classes: the imported as well as
the locally orgin progeny. from other direction the milk production
records (from 1979 to 1991) were clessified Into three groups according
to generation (1) the grand mothers, (2) the mothers and (3) tho
daughters.
Of) the basis of the previous classificatlon, 1505 lactation records
of 762 Holstein cows were used to estimate the phenotypic variations of
some productlon traits, (305-day milk yield, total milk yield, lactation
period and dry period) and its relatlon to origin, generation, seasoni of
calving. year of calving and parity as well as Ihe interaction between
origin and generation with season of calving, In addItion to estimation of linear and quadratic of age at the first calving, days open on milk production traits.