Police had spoken with the owner of the cows, and the owner was speaking to KiwiRail.
Neither police nor KiwiRail would confirm how the cows came to be on the track, saying it would be premature to comment.
The crossing at Kairua Rd was initially blocked. By 7pm the train had been moved and police were able to direct traffic through the intersection.
A KiwiRail spokesman said the train was delayed for about two hours while the section of track was cleared and the train was assessed.
While cows could be a derailment risk due to their size, in this case the train only sustained superficial damage to the front and to two air hoses.
No other services were impacted and no KiwiRail staff on the train were injured in the incident.
In the past five years there have been 37 stock trespass incidents reported in the Bay of Plenty, of which 19 involved collisions.
The KiwiRail spokesman said it was farmers' responsibility to keep stock from wandering on to the line, just as it was with farms that adjoined a state highway.
"This incident is a reminder for farmers to ensure their stock is adequately secured, for the safety of both the stock, property and other people."