The first analysis of samples collected from Southland dairy cows that died or fell ill after eating swedes has confirmed that they suffered liver damage.
The industry body Dairy NZ collected blood and autopsy samples from some of the affected animals as part of investigations into why the traditional winter feed crop caused them to die or become sick with symptoms similar to facial eczema, earlier this year.
Investigators were still leaning towards the theory that something in the swedes, such as compounds called glucosinolates in the leaf material, was likely to have triggered the response.
But Dairy NZ's regional team leader Richard Kyte said it was still too early to reach a definitive conclusion and further work would be done in the new year to fill in more of the jigsaw puzzle.
"We've surveyed 120 dairy farmers and we're going to be in the process of the graziers as well and out of this information we'll be looking at farm management practices and that would cover management of the crop and how it's planted and fertiliser as well as practices around grazing, the cares upon it and what sort of supplements were also fed with the crop.
"So that's a major part of the work and that'll give us certainly a better view of what happened, why and how, a better understanding."
Mr Kyte said the first tests also indicated that the severe reaction in cattle was not confined to the herbicide tolerant variety of swede that was now widely used in Southland.