Results from a New Zealand low-energy-input fish silage project are extremely promising for farmers, scientists say.
Initial trials have shown livestock fed the fish by-product expel less methane and dairy cows that consume the silage produce milk with a significantly higher omega fat content.
Jim Gibbs, a senior lecturer at Lincoln University who was involved in the trials, says until recently producing fish silage was both an energy-intensive and expensive exercise.
He says this changed when the founder of New Zealand fishing company United Fisheries, Kypros Kotzikas, employed a biotechnologist to see if there was a better way. He said the biotechnologist came up with a new procedure that took all of the material and, with a low energy input, produced a by-product that was extremely stable and yet maintained most of the inherent value, at least to ruminents.
Dr Gibbs said the trials show that methane production is reduced when the silage is fed at targeted times during the livestock daily cycle, which will be of interest to dairy farmers for environmental reasons and in terms of minimising the loss of dietary energy.
The trials also showed a reduced faecal count of internal parasites in calves and replacement heifers.