My dry cows were allowed stay at grass for longer this year due to the good weather and ample grass supply.

Although they grazed reasonably tight, this meant the were housed in slightly better than the optimum body condition score. This of course can bring its own problems, in the form of large calves or calving difficulties due to the cow having excess fat it the birth canal.

One such problem, partly due to excess condition, reared its head last week. It wasn’t a difficult calving, but a case of milk fever (calcium deficiency), in a cow that is not due to calve for another two to three weeks. I have however, a fair idea of the cause.

I was feeding these dry cows’ moderate quality, stemmy but reasonably dry baled silage. I also have a small quantity of bales of very leafy silage. This silage was cut and baled on the same day, so the dry matter is quite low. It was also baled a few weeks earlier than intended because the contractor was there baling second cut silage that I couldn’t fit into the pit and it didn’t seem to make sense to make him come back in a couple of weeks to bale an acre and a half. Probably not a lot of logic in that as he has often come and baled two or three bales of paddocks for me. However, we’ll forget about that. This was the silage I had fed the day before my case of milk fever. As we all know some one of the predisposing factors leading to milk fever is low dietary magnesium and very leafy grass tends to be low in magnesium.

High dietary potassium is another risk factor. As these bales were cut earlier than they should have been, there is a possibility that they were high in K. Thirdly, a cow carrying excess body condition is at a higher risk of suffering from milk fever than a cow in optimum body condition and this cow is too fat!

Thankfully my cousin was on hand to help me get her out of the slats and on to her feet. I got a bottle of magnesium and a bottle of calcium administered under the skin and, fingers crossed she seems to be doing fine.

I’m afraid to feed any more of my wet lush silage though. There are only 10 or 15 bales of it, so I’ll just wait and feed it to my weanlings when I house them. Funny a couple of little mistakes shall we say, when mounted on top of one another, can add up to, as we say in this part of the country, “a whole handlin”.