Oz writes

For a UK cow calving mid jan (in the '60's) this is the typical
production at month end. Animal milks for 305 days and dry for 60 days.

That's not quite right.
It's the average daily yield for the month when the animal is milking.
That is the production for the months of jan and nov is the given
yield/day but for half the month.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
Note: soon (maybe already) only posts via despammed.com will be accepted.