Abstract
This study was designed to analyse the effect of milking behaviour (temperament) of primiparous dairy cows on their milk and reproductive performance as well as survival to the second lactation. Milk performance, reproductive performance and culling data on 12028 Polish Holstein-Friesian primiparous dairy cows were acquired from the SYMLEK database. Using the methodology of the Polish Federation of Cattle Breeders and Dairy Farmers, the temperament of the cows was assessed as: 1 - calm, 2 - normal, 3 - excitable or aggressive. Primiparous cows from the analysed population were characterized by averagely normal temperament and optimal milking speed. Daily and lactation yield depended (P≤0.01) on the temperament of cows. Excitable (aggressive) cows had higher daily and lactation yield compared to normal and calm cows. The temperament trait was found to correlate (P≤0.01) also with functional traits such as milking speed, survival to the second lactation, and culling level. As milking speed increased, the proportion of cows with calm temperament decreased and that of excitable (aggressive) primiparous cows increased. As the temperament score increased, so did the proportion of primiparous cows sold for further breeding. Excitable (aggressive) primiparous cows had the lowest chance of survival to the second calving.