The word G. porog “fowl (domestic)” appeared in the Gnomish Lexicon of the 1910s (GL/64), clearly the cognate of ᴱQ. poroke “barn fowl” from the contemporaneous Qenya Lexicon (QL/75). In Common Eldarin: Noun Structure from the early 1950s, Tolkien had primitive words ✶porokĭ “fowl” and ✶porokē “hen” (PE21/82), indicating this Gnomish word may have remained valid in later Sindarin.

Neo-Sindarin: Gábor Lőrinczi proposed a neologism ᴺS. prôg “fowl, hen” as recorded in the VinQuettaParma Wiki (VQP), but I personally would just stick with attested ᴺS. porog, derived from *pórŏkē. Furthermore, I’d limit this word to just “fowl” or “*chicken”, and recommend ᴺS. huil or ᴺS. porochuil for “hen”.