Anderson said it was believed that Vitamin E improved ewe and lamb survival because it acted as an antioxidant to remove free-radical damage to the cell membranes.
As Vitamin E influences lamb survival, it is considered likely that Vitamin E deficiency is contributing to prenatal deaths.
Anderson said evidence existed that ewes and lambs treated with Vitamin E behaved differently, which contributed to their survival chances.
“There is some good data showing that treated ewes and their lambs behave differently. One of the most common observations by farmers is that the ewes and the lambs are more active.”
Anderson said results of a British study showed ewes treated with Vitamin E stood and tended to the lamb in half the time of untreated ewes. Their lambs also stood and suckled an average of 25 minutes earlier.
“Twenty-five minutes in a cold southerly in New Zealand could probably sometimes be the difference between life and death.”
Anderson said there had been various international studies showing that supplementing ewes in late pregnancy with Vitamin E improved lamb survival and lambing percentages.
“We do know supplementing ewes in late pregnancy will increase Vitamin E cells.”
The Optilamb programme in NZ, which had taken data over the past 20 years from 60 flocks, had also shown ewes and the hoggets treated with Vitamin E had a better rate of survival, he said.
Vitamin E deficiency was a problem in NZ pre-lambing, even though it was believed NZ pastures were riddled with Vitamin E. One of the key problems was that there was a low intake of Vitamin E through feed leading up to lambing. Winter pastures were not growing, so they had lost most of their Vitamin E, while brassica crops such as turnips had no Vitamin E available. Feeds such as hay and silage could also lose their Vitamin E.
It was also a highly stressful time for the ewes and stress drained Vitamin E reserves.
“We stress the hell out of our flocks in late pregnancy. We get them in and muster them, give them their pre-lamb treatments.
“The weather is also fairly horrible at that time of year, and farmers shear a lot of sheep before lambing which is again hugely stressful.”