Using waste milk is not worth the risks
Waste milk is milk that is not saleable. It usually refers to transition milk, or milk from cows which have been treated with antibiotics and whose milk is within the recommended withdrawal period.
It can also include milk from cows with high somatic cell count. It may seem like a good idea to feed this milk to calves, as it would have to be thrown away otherwise.
However, Animal Health Ireland maintains there are a number of reasons why you should not feed raw waste milk to your calves.
Milk from cows that have been treated with antibiotics and which is within the withdrawal period will contain residues from those drugs.
This can affect the taste of the milk resulting in the calves not drinking as much as they should.
Even worse, it can lead to the development of bacteria that are resistant to these antibiotics.
This means that if you try to treat animals with these antibiotics they may not work as effectively as might otherwise be the case.