Kumar N., Abadi Y., Gebrekidan B., Tegegne D.T.
College of Veterinary Medicine, Mekelle University, P.O. Box-231, Mekelle, Ethiopia
Kumar, N., College of Veterinary Medicine, Mekelle University, P.O. Box-231, Mekelle, Ethiopia; Abadi, Y., College of Veterinary Medicine, Mekelle University, P.O. Box-231, Mekelle, Ethiopia; Gebrekidan, B., College of Veterinary Medicine, Mekelle University, P.O. Box-231, Mekelle, Ethiopia; Tegegne, D.T., College of Veterinary Medicine, Mekelle University, P.O. Box-231, Mekelle, Ethiopia
The study was conducted on altogether 475 milch animals comprising of 223 indigenous and 252 Holstein-Friesian (HF) crossbred cows, maintained under farmer's managemental system in and around Mekelle (Ethiopia), were analyzed according to Least Squares Analysis to study the magnitude as well as direction of variation in their lactation length (LL), lactation milk yield (LMY) and peak-yield (PY) due to genetic and some non-genetic factors. The overall Least Squares Means for LL, LMY and PY were estimated to be 292.53±24.09 days, 1320.64±94.68 liters and 7.89±0.14 liters respectively. Genetic group and lactation order had significant effect (P≤0.01) on LL, LMY and PY. Season of calving had significant effect (P≤0.01) on LMY and PY but its effect on LL was non-significant. Effect of herd-size was significant (P≤0.05) on LMY while its effect on LL and PY was non-significant. Variation in all the traits due to location of herd and farming system were statistically non-significant. © IDOSI Publications, 2014.