How to implement a farm animal count identification solution?

Question

Automation

Good day!
I have about 150 cows on my farm. In the summer it is very difficult to count them, separate and mark special ones (sick, pregnant, etc.)
I remembered about nfc, there are ear tags with a label on Ali Express, readers. In general, I found everything I needed on Ali Express.
I also saw that Android phones can read tags, I don’t know if they can still count.
In addition, we need some kind of device that will be transmitted from the reader in the paddock and at the watering place to the data for me per hundred square meters.
Here is the process that this technology will solve on the farm:
1. Counting animals at the watering place and at the entrance to the fence (as in a quarantine shop)
2. Every day, send me a summary report on registered animals to my phone. That is, such a report: checked in - 130, not checked - 20.
3. Create, edit and read through any device (preferably a smartphone)
Next, you need to store the raw data somewhere for further processing. Data that can answer the following questions:
Which animal always comes to the watering hole last?
Which animal rarely comes to the watering hole?
Plz help me to think over the whole idea