I have just last night came across the derivation of the root of this word. I
was reading, finally, something I ordered last year from "Fatbrain, Inc."
online, "Merde Excursions in Scientific, Cultural, and Socio-Historical
Coprology" by Ralph A. Lewin, 1999. The word "poppycock" meaning in America,
"nothing," derived from the Dutch, "pappekak" meaning "soft dung." Apparently
the word may mean "soft coat" and maybe I might hypothesize, muskrat, four
logically equal to one beaver? They both share the same habitat. I have
trouble with the math, four bobcats = one beaver, considering the difficulty
of catching bobcats. Maybe it is a "substitute" economy term, as was the case
in the slave trade, according to Karl Polanyi, ("Primitive, Archaic and
Modern Economies, Essays of Karl Polanyi," edited by George Dalton, 1968)
silver and gold were reckoned on paper, but pig iron was transacted. Another
might be a linguistic problem "muskrat, bobcat." The full quote is
informative:

"It seems a shame that the good name of bullshit, a potentially useful
product, should have been debased in recent parlance to signify worthless or
misleading statements. The use of the word "poppycock," which in American
speech has much the same meaning, is considered more genteel, though it is
derived from a comparable Dutch dialect expression, "pappekak," soft dung.
(Packages of popcorn currently displayed in American supermarkets under this
name are presumably prepared and sold by people unaware of its derivation.)"
- page 5

George J. Myers, Jr.

That's not my final answer. Regis Philbin grew up around the corner from
where I am, on Cruger Ave., near the "Bronx Zoo" across "Trojan Field." (You
were either that or a Spartan.) I'm on Holland Ave., named after the English
Mayor of NYC 1750-1758.