Data management

12-month body weight

Twelve-month body weights were calculated for all calves born in each 6-monthly period each year between 1987 and 1997 that survived to 12 months of age. 

Body weights at 12 months of age were estimated by interpolating between the two weights recorded either side of this age.

The results are stored in CS10Data4 and documented in CS10Doc4.

Six-monthly least squares estimates were then calculated by general least squares Stats Regression analysis Generalized Linear Models...with period of birth (BYYMM), herd, sex and season of birth (BRTHSEAS) as fixed effects (see next page). This was done separately for periods March to August and September to February each year by first using the Spread → Restrict/Filter command.