Performance recording is generally necessary for the efficient management of dairy herds. There is a variety of recording systems currently available but interpretation of the results is hampered by an imprecise knowldege of attainable levels of performance and the magnitude of the shortfall that warrants interference. Mean values and standard deviations were calculated to provide standards for the assessment of other herds. Data were obtained for 6636 cows calving in one season in 50 herds (herd size ± s.d., 132.7 ± 44.5). Target values were considered to be the 75th percentile and interference levels the 25th percentile (Table 1).