I say about how many pairs I have. The calves are all gone by fall, so then I might say cows, but out of habit I often say pairs even then. Depending on who asked and why, I might elaborate to include replacement heifers. If I am talking to another cattleman they know when I say pairs, that I also have about 20% more replacement heifers and a bull for every 20 to 30 cows. If I am talking to a someone who I think needs to know and who might be unfamiliar with what I mean, I might go into more detail. I have discovered you may need to ask very detailed questions when talking to a more novice cattleman.
We leased out 100 acres to a family who had just purchased a neighboring parcel. I asked them how they planned to use it and they said it would be mother cows. I asked how many and they said 60. I wrote out a detailed contract limiting the number of animal units because I was worried about them putting all 60 pairs in for an extended time. It turned out they only had about 20 cows with calves and some pretty small yearlings.