Goats and donkeys were used to feed orphans and abandoned babies, even in the UK up to the early 20th century. Because there could be contamination and infection once milked, the babies suckled the animals directly. They even had special harnesses that held babies under the donkeys. They matched goats with babies so each goat fed 'it's' baby. Life or death for those poor babies.
They used to recommend women suckle puppies in the last stages of pregnancy to ensure the milk came in, and, as said earlier, puppies were also used to remove milk from ill nursing mothers as it was believed to be contaminated. Fascinating rather than disgusting.