Making penicillin using animals - specifically, a goat
Here is a link to a survivalist blog with a protocol for making penicillin. (I'm not recommending this by the way.)

Is it possible that the reference to the goat in Lucifer's Hammer is for the extraction of insulin (from the pancreas)? Have a look at the Wikipedia entry for Eva Saxl - in Shanghai during WWII her husband kept her alive with insulin extracted from water buffalo pancreas.