This expression became a term of encouragement after the following exchange in a live New York local Fox News broadcast at the end of the weather report.

Ernie: "It takes a tough man to make a tender forecast, Nick."
Nick Gregory: "Well, I guess that's me!"
Ernie: "Keep fucking that chicken."

The first line is a parody of a commercial for Perdue chicken from the 1970's, in which Frank Perdue uttered the tag line, "It takes a tough man to make a tender chicken." "Keep fucking that chicken" was the punchline of a joke of the same time about how Perdue did it.

To stay the course.

A phrase that can be used as a reply or advice in a variety of conversations, usually as encouragement (Keep up the good work, etc.) but also can also be defined as unproductive activity (fucking the dog, etc.) Can be used metaphorically or in the literal sense. Considered vulgar. Coined by news anchor Ernie Anastos of New York's Fox 5 network in a segue during a live newscast on September 16th, 2009.

It's what you say to a meteorologist after they announce the forecast.

Or in any and all situations ever.

To begin doing well in a manner prescribed by Ernie Anastos.

Expression, 21th century American English

1) An expression o encourage one to continue with an undesirable or menial task.

Basically a much funnier synonym for "Keep on keepin' on." It's what you say when someone tells you how they're struggling with something.