Comparative reproductive performance evaluation of Holstein Friesian cattle breeds in two different agro ecological conditions, Oromia region, Ethiopia

Abstract
Summary: Comparative study was conducted at Alage and Ardaita Agricultural Technical and Vocational Education Training College dairy farm to evaluate the reproductive performance of Holstein Friesian (HF) and associated factors in the two farms. The data collected from 2000 to 2015 on reproductive traits (n= 1688) were analyzed using general linear model procedures of SAS version 9.2 (SAS, 2008). The result revealed that an overall least square means and standard errors for Age at first Service (AFS), Age at first calving (AFC), Calving interval (CI), Days open (DO) and Number of services per conception were 29.70 ± 0.49 months, 39.75 ± 0.53 months, 465.76 ± 7.22 days, 188.11 ± 7.22 days and 1.31 ± 0.04, respectively. AFC was significantly influenced by agro ecology (P< 0.001) and year of birth (P< 0.01). Besides this, agro ecology (P< 0.001) and year of birth (P< 0.05) was significantly influenced by AFC. Year of calving and parity had significant effect (P< 0.001) on CI and DO. Except CI, agro ecology had significant effect on all traits. Service per conception was significantly influenced by agro ecology (P< 0.05) and year of calving (P< 0.01). Season of birth and season of calving was not significant on all reproductive traits. Except SPC, the result obtained for AFS, AFC, CI and DO were below the standard expected from commercial dairy farm. Poor efficiency of estrus detection and expression were the most probable management factors accounted for longer period of AFS, AFC, CI and DO. Improving the level of nutrition as well as efficiency of estrus detection system is required for optimal reproduction performance of HF breed in the area.