I was on a farm over the weekend where there wERE four cows with retained cleanings or retained placenta/afterbirth. The farmer had 90 cows calved, and he had two previous cases of retained cleanings this spring so six cases in total, or 7% of the herd with retained cleanings.

While not an exceptionally high rate, it is higher than you would like and the farmer was concerned that it might have been brought on by a mineral deficiency.