Estimations of the increase in milk production due to the introduction of maize silage to a dairy farm in a sub-tropical environment: A time series approach

A method involving time series modelling is provided for evaluating the effects of an abrupt intervention, such as the adoption of a new technology, when no control is available for comparative evaluation. The new technology was the introduction of maize silage into the feeding programme of a dairy farm in south-east Queensland. A model was developed using historical milk data from a nine-year period. This model was used to forecast subsequent milk production on the dairy farm had maize silage not been introduced, and these forecasts were compared with actual production after the introduction of maize silage. Milk production was 320 154 litres greater than forecast in 10 seasons over a four-year period after the introduction of silage. During the same period, production was 14 596 litres less than forecast in one season, with the remaining six seasons estimated to be within 5% of observed values. This resulted in an estimated net gain of 305 558 litres of milk above the amount expected had silage not been introduced, representing an average increase in production of 18% per annum