John says they're like great milk machines.

You've got to keep them quiet, only exercising enough to keep them in health.

If a cow is hurried or worried, or chilled or heated, it stops her milk yield.
And bad usage poisons it.

John says you can't take a stick and strike a cow across the back, without her milk being that much worse, and as for drinking the milk that comes from a cow that isn't kept clean, you'd better throw it away and drink water.

When I was in Chicago, my sister-in-law kept complaining to her milkman about what she called the 'cowy' smell to her milk.