Comparing autumn and spring calving systems: A farm system study on a commercial-scale dairy farm in coastal Taranaki

Abstract

In recent years, there has been a growing interest in shifting the calving system from spring to autumn on dairy farms on New Zealand’s north island. This change is driven by dry summers, particularly in coastal areas and an increased winter milk premium from Fonterra. In the present study a 2-farmlet trial comparing an autumn calving and a spring calving system was performed to investigate how changing the calving system would affect different aspects of the farming business on a commercial size dairy farm. The trial was run over three seasons and the farmlets were compared with regards to milk production, supplements fed and harvested, mating performance, animal health and profitability. The autumn herd produced 9 – 19 % more milk solids per cow and 5 – 17 % more milk solids per hectare than the spring herd. The requirement for supplements was 23 – 40 % higher on the autumn farmlet. The profitability was 14 - 37% higher for the autumn farmlet due to higher milk production combined with a winter milk premium. The study shows that it can be possible to increase farm profitability by changing the farming system from spring to autumn calving, especially in summer dry areas.