The effect of mating system and herd size on reproductive performance of dairy cows in market oriented urban dairy farms in and around Addis Ababa

摘要

A retrospective data analysis and a cross sectional survey was conducted to study the effect of mating system and herd size, on reproductive performances of cows in smallholder market oriented urban dairy farms in Addis Ababa milk shed. Thirty three dairy farms comprising 232 cows were visited and data on reproductive performance, cow attributes, type of mating, body condition score and general farm management practices were collected. The mean (±SD) age at first service (AFS), age at first calving(AFC), service per conception (NSC), calving to conception interval (CCI), and duration after last calving (DALC) were 23.1±6.4 months, 33.2±6.7 months, 2.0±1.2, 176.8+79.0 days, and 172.2±159.3 days, respectively. Both AFS and AFC were significantlydifferent (P<0.05) between farms and mating systems. There was a significant difference (P<0.05) in the NSC between farms and between the mating systems (P<0.001). The first service conception rate for pregnant cows (n=77) was 45.5% for all farms, 60.0%for AI (Artificial Insemination) farms, and 40.0% for NS (Natural service) farms with significant difference (P<0.05) between mating methods. DALC was significantly longer (P<0.05) in small farms. Effect of mating system-herd size interaction was not significant on all performance parameters. The prevalence of reproductive health problem was 27.2% and the major reproductive health problems were retained fetal membrane (33.3%) and abortion (22.3%). In conclusion, the present study showed that both the herd size and the method of mating were important risk factors that affect the reproductive performance. To minimize the cost of bull keeping in small farms and mitigate the poor AI delivery system prevailing in Ethiopia, establishing a bull service station for collective use should be considered.