National Beef Recording Scheme: Recording Manual. MASON, W.E., BEILHARZ, R-G., and CARRAILL, R
Birth date, weaning weight and date, sex of calf, year of birth, age of dam and management group were recorded for each calf. Birth weights were recorded in only one herd and standard values of 27.2 kg and 29.5 kg were used for heifer and bull calves respectively in other herds. For the purpose of the analyses age of dam was restricted to five groups, two-, three-, four-, five to eight-, and over eight-year old.