Every spring well-meaning calf rearers manage to poison calves by trying to save money on home-made milk or colostrum feeders. When the large plastic bloat oil drums are empty, people use them as calf feeders when fitted with tubes and teats.
What is not realised is that the residue of the bloat oil is toxic to calves and it takes more than one hosing out to get rid of it. The rule for cleaning any chemical container is that it must be given at least three good washes and rinses. Give it another to make sure it's clean.
You also often see smaller chemical containers being used for feeders for small groups of calves, and these can be equally as dangerous if not washed thoroughly. You can often see the word "Poison" printed on them.
The other killer of young calves is lead poisoning where they lick old paint off the sides of sheds or old doors used as barriers inside pens. Most calf rearers know not to use treated shavings with arsenic in them, but again mistakes are made and calves die with painted surfaces.
When calves are treated with animal remedies it's very important that the instructions are carefully read and adhered to. Overdosing with organophosphate insecticides and anthelmintics to kill worms also occurs with fatal results. "Read the instructions" seems to be such a boring message – and it's only done when all else fails! There are plenty of cases of farmers rushing to read the details on the packet after the first animals treated have collapsed!
Then each spring when it's time to do some garden pruning, calves and young cattle get poisoned from eating toxic garden shrubs that have been thrown into the paddock as pasture is short. There's a wide range of toxic shrubs such as oleander, rhododendron, yew, macrocarpa, ngaio, Jerusalem cherry and laburnum – and stock don't need to eat much of these to be poisoned.Toxic shrubs are often not eaten when they are fresh, but seem to become more attractive and palatable when wilted. So the rule is don't throw garden prunings into a paddock.
Fresh clean water is essential for all stock, but occasionally animals get access to stagnant water covered in blue-green algae which can cause kidney damage, incoordination and death. Such areas with dirty water should be fenced off.