الفهرس | Only 14 pages are availabe for public view |
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. |