Faculty of Veterinary Medicine, Addis Ababa University, P.O.Box 34, Debrezeit, Ethiopia
Mekonnen, T., Faculty of Veterinary Medicine, Addis Ababa University, P.O.Box 34, Debrezeit, Ethiopia; Bekana, M., Faculty of Veterinary Medicine, Addis Ababa University, P.O.Box 34, Debrezeit, Ethiopia; Abayneh, T., Faculty of Veterinary Medicine, Addis Ababa University, P.O.Box 34, Debrezeit, Ethiopia
Retrospective and prospective follow-up studiers were conducted during November 2004 to April 2005 in and around Arsi-Negelle, to evaluate the reproductive performance and efficiency of Artificial Insemination (AI) service in field condition. A total of 2944 dairy cows/heifers were included in the retrospective study whereas 168 dairy cows were used in field follow-up study. The first service non return rate (NRR) in the retrospective study was found to be 86.6% (n= 2511), which was much higher than the NRR (48.2%; n=81) recorded in the field follow-up study. The first service NRR of 48.2% recorded in the follow-up study which is supposed to be due to pregnancy was much lower than first service pregnancy rate (34.5%). This may be attributed to factors including failure of return to estrus or farmers choice of natural mating in cases of insemination failure. Analysis of the breeding records of 622 dairy cows indicated that the mean duration of calving to first service (CFS) in local breed cows (mean±SD: 241±18.5 days; n=205) was significantly higher (P<0.01) than those of crossbreed cows (mean±SD: 182.0 ± 9.87 days; n=417) indicating the low reproductive efficiency of local breed cows. Only 4.5% of dairy cows (n=28) had CFS less than 80 days. The average inter service interval (ISI) recorded in the retrospective study was (39.8 ± 3.39 days) which was a bit higher than that of the field follow-up study (33.5± 4.66 days). The proportion of cows/heifers (26.3%; n=23) that had ISI lying within the normal range of 18 - 24 days was much lower than the recommended 60%. Problems associated with management, heat detection, timing of insemination and semen quality were identified as the probable causes of the low efficiency of AI obtained in the field study.
