To test the accuracy of 30-day TIM with 15 and 45-day TIM of milk recording to estimate the lactation yield and to measure the effect of genetic group, parity and season of calving on the accuracy, 1220 lactation records of Friesian x Arsi cows were utilized. The lactation yield was estimated for lactation length of 210-305 days. The accuracy was measured in terms of absolute difference and percentage difference between actual and estimated yield. The study revealed that 15, 30 and 45-day time interval can estimate lactation yield accurately to extent of less than five percent bias...