DairyNZ chief executive Dr Tim Mackle says the joint decision three years ago to eradicate Mycoplamsa bovis was a difficult call.
Zeolites are used in European barn farming but how they might work on pastures under New Zealand conditions is unknown, Chapman told the recent Future Perspectives Dairy NZ Farmers’ Forum in Timaru.
However, a DairyNZ trial has now shown proof of effectiveness, he said.
“Basically zero percent of the animals treated with zeolite showed signs of even sub-clinical hypocalcaemia (milk fever). But an untreated group were at about 38% signs of hypocalcaemia. That’s a stunning result.”
Chapman was outlining different snapshots of current research by way of brief videos.
The leader of the trial, senior scientist Dr Clair Phyn, told the forum by video that feeding synthetic zeolite to transition cows in the lead-up to calving was a way to improve calcium levels following calving.
It has been shown under European systems that it is highly effective in reducing risk of milk fever.
“We’ve now shown under NZ under grazing conditions that feeding cows synthetic zeolite for two-three weeks before they calve improves their calcium levels in blood at calving. This means they have a lower risk of clinical and sub-clinical milk fever.”
They had also seen promising effects on reproductive performance.
“We’re now scaling up across several thousand animals under commercial conditions in several herds to see if synthetic zeolite precalving can improve uterine health and reproductive performance,” said Phyn.
Zeolites are aluminosilicate minerals commonly used as commercial absorbents.
In cows they work as calcium binders, limiting the amount of calcium available from pre-calving feed. This forces the cow to adjust by drawing on its own calcium reserves, effectively activating its natural defences against hypocalcaemia.
Chapman said the zeolite work is part of a large programme called Lifetime Productivity, to understand the factors affecting the performance of the national herd. Notably this includes preventing cows exiting the herd early, supporting their health and welfare and giving them a life with few problems, minimal costs and best possible production.
The zeolite study is seen to justify scaling up into a larger study this spring in 2000 cows in four or five herds.
Chapman said half would be treated with zeolite and half managed as normal without it.
“That’s going to give interesting information on reproduction, transition cow health and the production of those cows in early lactation and beyond.”
Apart from naturally occurring mined zeolite used in various products, zeolite is not yet available in NZ, but Chapman said it is marketed in Australia by a company working with 60 farms. The company is interested in moving into NZ but will probably wait for the results of the large-scale study.
Chapman said the Lifetime Productivity programme could raise productivity and profit by $500 million. That would be $12-$15 per cow per year “if we can get our heads around some of these problems”.