Genetic parameters of average milk flow recorded electronically from milking parlours and automatic milking systems in Estonian Holstein dairy cows

Abstract Text: The objective of this study was to investigate the feasibility of recording electronically average milk flow rate (AFR) from milking parlours (MP) and automatic milking systems (AMS), and to estimate heritability of AFR and genetic correlations with other traits in Estonian Holstein. AFR data were available for 11,001 cows at the beginning of their first lactation from 23 farms with AMS and from 34 farms with MP. The genetic correlation between AFR, measured by AMS and MP treated as two different traits, was 0.918. AFR had moderately high heritability (0.495). There was a positive genetic correlation with milk yield and a negative correlation with both fat and protein contents. The genetic correlation of AFR with SCS was 0.27, which decreased to 0.147 at the end of the first lactation, and increased (to 0.233) at the beginning of the second lactation.

Keywords: Genetic parameters, Estonian Holstein, Milk flow rate