"Kye" is the singular of "kine". In fact, Kine is just an -n plural of "Cow" (Cowen) pronounced in a particular way. Kine, spelt like that, found its way into the King James Bible. "Swine" is another -n plural (in this case of Sow) though I've never heard anybody call them Sye.

The -n plural is, in fact, very common all the way up the East of England (I think it may be Danish as this was the area of the Danelaw). Another one, very common until recently is Shoon (for Shoe).

I know one or two people in Cambridgeshire who seem capable of using -n interchangeably with -s for plurals, though they do use it regularly for certain words.

:-)