Data management

When this study commenced the data were entered into flat dBase files; data checking was time consuming. Subsequently a data management system was developed that checked that dates of calvings, deaths and disposals were in line with existing animal information and that animal identification was correct.These checks are similar to those included in a more general system developed by Metz et al. (1999)

For the above reasons data collected during 1986 were not included in the analysis. Furthermore to ensure for the purposes of this case study that all variables are calculated over the same period only values calculated up to 1997 will be used. Thus, we shall use data collected for eleven years from 'year' 1987 to 'year' 1997 inclusive. 

Data sheets were filled in monthly when animals were brought to the crush. The data sheets were headed with the date of recording and the herd to which the animals belonged (see Video 1).

Part of the dBase data file is contained in CS10Data1 and documented in CS10Doc1.