Where supplementary feed is used to support a greater stocking rate, large milk production responses do not guarantee greater profit.
"All the work shows is that it's really easy to make more milk by putting more supplements into a system and it's a lot harder to make more profits" DairyNZ strategy and investment leader Dr Bruce Thorrold told The Country Early Edition's Rowena Duncum.
Listen below:
"Farmers can use supplements profitably, and this work in Northland has really laid out the ground rules for doing that ... but if your systems are inefficient, then there'll be more feed going in, there will be more methane being produced but not necessarily any more money coming out the bottom".
The question of supplements and farm systems was "almost tribal" said Thorrold.
"Whenever we do some work on this we get very strong feedback from farmers".
Find out more about the research here.
Also in today's interview: Thorrold had tips for looking after cows in dry conditions and the DairyNZ Farmers' Forums coming up in February and March in Northland, Waikato, Taranaki, Canterbury and Southland.