College of Veterinary Medicine, Mekelle University, PO Box-231, Mekelle, Ethiopia
Kumar, N., College of Veterinary Medicine, Mekelle University, PO Box-231, Mekelle, Ethiopia; Tkui, K., College of Veterinary Medicine, Mekelle University, PO Box-231, Mekelle, Ethiopia; Bisrat, A., College of Veterinary Medicine, Mekelle University, PO Box-231, Mekelle, Ethiopia
The study was conducted on 475 milch animals comprising of 223 indigenous and 252 Holstein-Friesian (HF) crossbred cows maintained under farmer's management system in and around Mekelle, Ethiopia. Data were analyzed according to least squares analysis to study the magnitude and direction of variation in days open (DO), calving interval (CI) and number of services per conception (NSC) due to genetic and some non-genetic factors. The overall least squares means for DO, CI and NSC were 157.0±62.0 days, 453.6±88.3 days and 1.7±0.2 services, respectively. The genetic constitution of the animals influenced DO, CI and NSC significantly (p<0.01). Lactation order had significant effect on CI and NSC (p<0.01) and DO (p<0.05). Season of calving, location of the herd, herd size and farming system had not statistically significant effect on all traits.