The objective of this study was to determine when a cow would accept a foster calf after being separated from her own calf. Two different breeds were studied: 24 Swedish Red and White (SRW) and 24 Swedish Holstein-Friesian (SHF). Four different times of separation from their own calf were studied: 1) immediately 2) four day 3) 26 days 4) 178 days. There was no significant of the four different times after separation. Calves were sniffed more by SRW than by SHF cows during both observation periods. Some cows showed aggressive behaviour, but there were no significant differences between the two breeds. Cows that had been separated for 178 days had less calves suckling than those that had been separated immediately or for four days from their own calf. Cows were suckled more by SRW calves than SHF calves. In conclusion, alien foster calves are accepted by both breeds of dairy cows and from different stages or lactation equally well.