CRV sales development specialist Gert Jan van den Bosch, of Arnhem in the Netherlands, spoke at a field day near Gore last week.
When he told his Dutch colleagues he was spending a week in New Zealand to talk to farmers about feed efficiency, they laughed.
"They said ‘what are you going to tell them about an efficient cow?’ because you here in New Zealand are the inventors of breeding efficient cows."
Farmers knew how much milk an individual cow produced but remained in the dark on how much feed it had to eat to produce it.
A study on the feed intake of more than 12,000 cows was launched on five research farms in the Netherlands in 1990.
The study was expanded to research the feed intake of cows on commercial dairy farms in 2017.
Some of the cows were producing 1kg of milk from eating 1kg of dry matter.
"Some cows were producing 2kg of milk out of the same kilogram of dry matter."
Another finding showed the top quarter of the most efficient cows in a herd were 50% more profitable than the bottom quarter.
The difference in bodyweight between the lightest and heaviest cows in the herd was 20kg.
A farmer was unable to spot the most efficient cow in a herd by looking at it, he said.
"We assume a smaller cow is more efficient because it needs less feed for maintenance but she also needs to have a high production or she is not efficient."
The heritability of feed efficiency and feed conversion was 10%, Mr van den Bosch said.
