111. Genetic and phenotypic variation and consistency of cow’s preference and circadian use of robotic milking units

Abstract

Many dairy herds use automatic milking stations (AMS) and in large herds, cows usually have access to two or more AMS, and consequently must make a choice between them whenever they go for milking. For this study, we assume that the degree of using the same milking box is an expression of preference. We used a total of 4,665 cows from a Holstein and a Jersey cohort covering 12 commercial dairy herds in Denmark to estimate heritability, repeatability and individual level correlations between preference choice score (PCS), Time_profile (preference for specific clock hours) and associated milking and behaviour traits. The average PCS was 0.43 (Holstein) and 0.41 (Jersey), respectively. Both PCS and Time_profile had low heritability (0.07/0.11 Holstein, 0.13/0.04 Jersey) and moderate repeatability (0.47/0.40 Holstein and 0.50/0.42 Jersey) and were weakly correlated to each other (Holstein 0.18 and Jersey 0.17) and weakly correlated to milk yield (ri range 0.0 to -0.10).