Data from 558 Friesian-Bunaji crossbreds were used for this study. Season and period of calving significantly (p<0.05) influenced 305-day first lactation milk yield while calf parity number significantly (p<0.05) influenced first milk yield at 2, 4, 6, 8 and 10 months. First lactation yield of crossbreds did not follow a particular trend but was better in animals calved in the late wet season (982.41kg) followed by early dry season (950.45kg) and least in the early wet season (868.19kg). Subsequent 305-day milk yield was highest (951.91kg) in Period 2006 – 2010 and least (425.17kg) in period 1986 – 1990. It is concluded that crossbreds from the 2nd calf parity, calved in the late wet season have an optimum 305-day first lactation yield subsequently.