The present study was undertaken to investigate productive and reproductive performances of F1 crossbred cows to produce and develop improved dairy cattle breed at on station and back up the on farm crossbreeding program at Holetta Research Center (HRC). One hundred fifty three F1 crossbred heifers were used to study growth performances and 111 worldwide sire (WWS) and 42 Kality (NAIC) sire records were used to analyze the data. A total of 802 milk records out of which 711 from worldwide sire (WWS) milk records and 91 from Kality (NAIC) bulls’ milk records were used to analyze the milk production performances. Least squares means of growth traits in this study birth weight (BWT), average daily gain (ADG) of crossbred heifers was 24.83 ± 2.33 kg and ADG ranges from 0.437 ± 0.01 to 0.546 ± 0.02 kg respectively. Least squares mean for age at first service (AFS), age at first calving (AFC), calving interval (CI), and number of service per conception (SPC) were 26.4±0.8 months, 35.7±o.81 months, 500.32±2.92 to 395.64 ± 4.9 days, and 1.2 ± 0.2 to 2.37 ± 0.05 services, respectively. Lactation milk yield (LMY) obtained from this result reflected progressive trend from 1st to 5th parity (1874.65 ± 67.7 to 2582.69 ± 111.2 kg) and started declining thereafter. The declining trend observed after the 5th parity is the normal biological phenomenon from dairy cows under normal conditions. The improvement gained from this result is the outcome of the of management procedures and practices followed which have accounted for 15.5 % of early calving of young heifers and 21 % in milk yield increments made from Frisian Boran (FB) crossbred cows at HARC. The overall observed growth, reproductive and milk yield performance of FB crossbred dairy cows at HARC has shown progressively significant improvement. Thus in order to continue with the crossbreeding for development of F1 50% crossbred dairy cows to maintain the on station and backup the on farm breeding activity there is a need to do intensive and proper performance evaluation based on defined breeding objectives. Culling procedures to avoid milking cows beyond the 5th parity is important. Research centers have to put maximum efforts to improve routine management activities to maintain performance evaluated animals at the centers at all levels.
