“You have to be onto it with milk fever,” Sol says. “We give them magnesium in the troughs, spread it on paddocks and make sure we get some into them, even on wet days.”
Magnesium is a vital means of controlling milk fever on the 400ha farm near Methven; it is applied by spreader onto grass.
“We start it as soon as the cow goes from the crop to grass,” Sol says. “In August they will go on dusted grass and stay there until the end of October. The milkers, colostrum, springers -- every head will go on dusted grass.
“If we have a nice day – no wind -- we can do it up to three days in front. The last calving was pretty intense with the wind and rain so we ended up dusting every day before we opened the paddock to the cows.”
If the weather is fine and they can supply the magnesium as needed, the milk fever problem does not arise.
“Our main problem is if we get a few rainy days in a row then we can’t dust it on the paddock and we can’t put it in the silage. It will melt before we get to the paddock”
On rainy or windy days they often add the dust to the silage wagon to give the cows the recommended dose. “That’s the only way to get the magnesium into them. You have to be on top of it. If over one or two days they don’t get the magnesium they will have milk fever; you will lose a few cows.”
Sol says wet weather and snow is a big issue on the property and they need to be able to supply magnesium in the cow sheds.
One option is Ozmag 523 magnesium oxide, a granulated formulation for adding to silage and other feeds in a controlled way.