Published online by Cambridge University Press: 20 November 2017
Genetic evaluations in the United Kingdom (UK) for Somatic Cell Count (SCC) are currently based on a single trait repeatability model using the first five lactations. Only cows with completed lactations are included. However, to utilise information from cows with part lactation records and to achieve a better correction for environmental effects, a test day model (TDM) evaluation would be preferred. The objective of this study is to estimate genetic parameters needed for such a TDM evaluation by utilising a random regression (RR) approach.