Split Calving Trial 1997-2000
This 3 year trial at NARF compared all autumn calving with spring calving. The farm has very wet soils and was a real test for winter milking, but the trial showed that a high level of pasture management was more critical to the success of winter milking than soil type.
The autumn calving cows had longer lactations and higher production per cow than spring calvers but the lower stocking rate caused slightly lower production per ha.
Profitability of the autumn calving farm was driven by the size of the winter milk premium and the cost of imported supplements.
The results showed the premium for May to July at the time needed to be 90 cents/kg milksolids for autumn calving to be as profitable as spring calving, and the Northland Dairy Company used this information to set their winter milk contracts.