The objective of this study was to evaluate the reproductive performance of Arsi-Holstein-Friesian crossbred dairy cows at Assela Model Agricultural Enterprise (AMAE). A retrospective study was carried out using data recorded from 1996 to 2011 to evaluate number of services per conception (NSPC), days open (DO), calving interval (CI), age at first service (AFS), and age at first calving (AFC). Fixed factors considered were year (16), season (3), parity (6) and blood level (4). Data of cows with complete information were considered, and a total of 855 records for NSPC, 678 records for DO, and CI, 177 records for AFS and AFC, were used. The overall least square means of CI, DO, AFS, AFC and NSC were 488 days, 209 days, 951days, 1314 days, and 1.818, respectively. Season had no significant effect on AFS, AFC, CI, DO and NSPC. Year of calving had significant (p<0.05) effect on CI, DO, AFS and AFC. Year of calving showed significant influences (p<0.01) on NSPC. There was no significant difference among blood levels in NSPC. There was difference (P<0.05) among blood levels in CI and DO. First parity showed higher (p<0.05) values for calving intervals and days open than that of third and above, while, second parity was intermediate. There was significant (p<0.01) difference in AFS and AFC among the blood levels.The NSPC for 4th parity was shorter than that of the 6th+, whereas, the other parities were intermediate. Except NSPC, blood levels had an economic importance in determining reproductive performance of dairy cows. Year had an important role in determining the performance of dairy cows indicating that the variation in feed availability and quality as well as variation in management through the years. Therefore, stabilized environment, setting breeding program, and benchmarking parity number is important to improve reproductive performance of the farm.
Keywords: Arsi, crossbred, Holstein-Friesian, reproductive