The word ‘par’ is a reference to the domesticated breed of the ancient bull. We use these two words interchangeably because the bull was also domesticated much before the biblical era. The ‘par’ (only the male bull) was the main sacrificial offering mentioned in the Bible. There are very lengthy details of how to prepare it as a sacrifice in the Temple. The ox (shor) and oxen, which are basically the same animal but are commonly castrated adult male cattle, have never been used for sacrifice either.
The female of ‘par’ is ‘pa•ra’ (cow). Cow is then the adult female whereas the ‘par’ is the bull, which is an intact male. The cow, too, has never been used for sacrifice. In fact, ‘pa•ra’ is mentioned only once in the Bible. Obviously, because of the abolishment of sacrificial practices, neither the male nor the female were ever mentioned in the New Testament.
There was, however, only one cow that was to be a sacrifice: the red heifer.
“This is the ordinance of the Torah which the Lord has commanded, saying, Speak to the people of Israel, that they bring you a red heifer without spot, which has no blemish, and upon which never came yoke”
It is interesting to mention that the word for atonement, forgiveness, absolution in Hebrew is ‘ka•pa•ra.’ ‘ka’ means: as or like, and ‘para’ means, as said, a cow. So the highly spiritual idea of atonement is still philologically connected to the cow. It is also very interesting that in India the cows are held holy.
As to the red heifer, this unusual cow is the reason for naming the ladybug in Hebrew the unusual entomological name: ‘the cow of Moses our Rabbi,’ ‘pa•rat Mo•she Ra•be•nu.’