Effect of month of calving on the production of Queensland dairy cows

Abstract

In all districts, except the Atherton Tableland and Mackay, the production of cows which calved in the months of December to March was lower than that of cows which calved in other months of the year. Cows which freshened in the months of June and July produced 20 per cent. more milk and butterfat than those which calved in December, January or February.
The month of calving influenced the length of lactation of cows. Cows which calved in the late winter and spring completed longer lactations than those which calved during other periods.
Lactation curves of cows which calved in each quarter of the year were prepared for two districts. They showed that cows which calved in the third quarter of the year produced more milk and butterfat for a period of 6-7 months of a total lactation of approximately 10 months.
The influences of breed and age of animal were considered in relation to production of cows which calved in the various months. It was found that all breeds showed similar trends in calving patterns and amounts of production.