DairyNZ's feed review visits have revealed some farmers are overfeeding their cows and rotating their pasture poorly.
More than 700 farmers have registered for the visits which are intended to help farmers grow and harvest more pasture to save costs.
DairyNZ productivity team leader Rob Brazendale said more than 450 visits had been completed and only about one third of farmers had their pasture rotation spot on.
"What we're doing is looking at the rotation that the farmers are actually on on that day compared to the target line, and getting a quick assessment really of whether they're on track and just need to keep on doing what they're doing. Or if they're a little bit off track, just need to tweak a few things, or reduce the amount of feed allocated to cows or increase the supplements slightly, or thirdly, they're well off track and we really recommend they get someone in to do a comprehensive feed management plan for them."
Mr Brazendale said some farmers were also over-feeding their cows after calving.
"There is kind of a general over estimation of how much a cow can eat in early lactation. It takes about six weeks from the time a cow calves for her to reach maximum intake, which for a 500kg cow might be around 18 kilos of dry matter, but from the day she calves it's probably around 12, 13 and slowly increases.
"We've seen quite a number of farms where they've been trying to feed their cows 18 kilos from right at the start of calving and she simply won't eat that much, therefore we see quite a bit of feed wasted."
Farmers have until the end of August to register for a feed review visit.