The squadron’s initial insignia was approved by CNO on 26 March 1968. The design centered on a bull was selected to symbolize the spirit, pride and mission of the unit. The Bulls current insignia was based on the Schlitz Malt Liquor logo. Over the years, the size of the testicles has been changed several times. After the Tailhook scandal, the testicles were removed completely from the logo for a time. Nickname: Bulls, 1968–present. This from Wikipedia.

So, yes, the nads have come and gone, resized, etc. It is totally fitting that following Tailhook '91 the Bull was castrated, seeing as how the Navy gelded itself for Patsy Schroeder.

All I know is back in the early 80's he was sporting an impressive pair. I'm a Tomcat guy and had to tip my hat at this logo, even if it was on a "flying shoe-box"