A total of 1214 first lactation records of Murrah buffaloes collected from six military dairy farms viz., Agra, Ambala, Bareilly, Ferozepur, Lucknow and Meerut spreading over a period of 30 years were utilized to assess the effects of farm, period, season and age at first calving on 300 day first lactation milk yield, first lactation period, weight at first calving, first dry period, first service period, number of services per conception and first calving interval. The least-squares means were 1704.51±25.41 kg, 308.27±3.89 days, 501.59±4.04 kg, 184.93±7.40 days, 196.15±7.0l days, 1.23±0.30 nos. and 497.54±8.90 days, respectively for the above mentioned traits. The farm effects were significant for all the traits except the number of services per conception. The period effects were significant for 300 day first lactation milk yield, first lactation period and first dry period. Similarly, significant effects of season of calving on first lactation period, first dry period, first service period and first calving interval were observed. Weight at first calving, 300 day first lactation milk yield and number of services per conception were also observed to be significantly affected by the age of animal at the time of calving.