The weather has treated us well this winter with higher temperatures and lower rainfall. So with more feed around and a better calving environment surely we should be seeing less down cows right? 

Unfortunately, on some farms we are seeing the opposite effect! We’re hearing of more cows that are struggling to get up, despite magnesium and other mineral supplementation. The daily requirements of magnesium does not change, however in a normal West Coast winter/early spring, we tend to have high rainfall and some magnesium is washed off the pasture. This in turn decreases their daily intake. Given that many farms are using the same mineral supplementation protocols as last year and the weather has been mild, we are likely seeing cows with excess magnesium this season.

Since magnesium is not stored in the body, the level in the blood only indicates intake during the last 24 hours. We know that magnesium and calcium absorption have a significant effect on one another. High magnesium levels in blood pre-calving will lead to milk fever (low Calcium) at calving. In this situation, cows can go down and won’t respond to calcium bag treatments. Phosphorus also has a part to play in this complex metabolic issue around calving as low phosphorus can also be associated with down cows. The key point is that different farms can have different reasons behind their down cow problem.

Essentially, cows can go down with milk fever signs when either calcium, magnesium, or phosphorus levels are abnormal during the dry period. The normal method of treatment for these cows more often than not will result in a dead cow, as these animals require different treatment in order to get back up again.