The aim of this study was to evaluate traits other than production (TOP) over multiple seasons and lactations in Holstein-Friesian (F), Jersey (J) and crossbred (F × J) cows milked once a day (OAD) in New Zealand. Cows in different lactations were scored for 18 TOP during three consecutive seasons from 2013 to 2015. Overall, there was a decrease in scores for stature, body capacity, rump width, legs, rear teat placement and dairy conformation over seasons, and a simultaneous increase in the scores for rump angle, udder support, udder overall and body condition score. Most udder traits showed a gradual decrease over lactations. The results of this study showed that improvements in TOP can be made by selecting for a particular body conformation, which is due to a correlated response to selection over time. Jerseys better adapt to the shift from TAD to OAD milking than F × J and F due to their better udder conformation.