The present study aimed at testing the effect of using Holstein germ plasm
to improve productivity and longevity of European Friesian in Egypt. This was
conducted by comparing performance of the crossbreds of Holstein x Friesian (HF)
with that of their purebred Holstein (H) mates. Data used comprised 1852 and 2504 lactation recods of 425 Holstein (H)
;:"e 500 Holstein X Friesian (HF) cows. All cows were sired by a common pool of 209
Holstein bulls. Data were collected over the period from 1991 to 2000 and were
analysed by General Linear Models (SAS, 1996) and Mixed model (Harvey, 1990). Least squares means for 305-day milk yield, lactation period, calving interval
were 7438 kg, 336 and 429 day for Holsteins and 6119Kg, 303 and 390 day for
Holstein Friesian, in respective order. Genetic differences were highly Significant for
sire (P<0.0001) and nonsignificant between the two genotypes ir all traits except for
CI (P<0.0336). Parity exerted significant effect on the three traits (P< 0.0001-0.0003).
The 305 dMY increased significantly from the 1^st to the 2^nd lactation and tended to
decrease thenafter. Indicators of longevity (number of completed lactations, herd life and
productive life) and productivity (annualized milk yield and milk per day of cowage)
showed no significant cifierences between the two studied genotypes (H and HxF).
The results refer to the feasibility of upgrading productivity of cows with European
Friesian genetic background by using pure Holstein semen.