Help with adding cattle to my business

hey all,
i have a farming business.

taking delivery of 33 pregnant cows ($1390/each).
9 have delivered ($0).
42 total inventory as of today (changing every day).

how do I record this in our software? Do I set up 1 inventory for each and calculate weight*current price per weight for each cow? Or can I set up just one inventory item, “Cow” ? Or do I separate calves from momma cows- and if so, how do I eventually convert calves into momma cows in inventory?


Set up one Inventory Item for “Cows - Purchased”

Then as calves are born take them up as Inventory Items based on their intention
Calves 2017 - Breeders
Calves 2017 - To be sold

As Calves 2017 - Breeders become cows, just rename the Inventory Item to “Cows 2017”