Identity follows the animal. Birth, movements, treatments, weight and destination belong to one record, and a farm that keeps this in a notebook cannot answer an inspector's question in the time available.
The land sets the herd size. There are only so many acorns and so many hectares, and the permitted density is both a rule and a biological fact, so planning the herd starts from the pasture rather than from demand.
Certification is a record-keeping discipline. Dates, feed, densities and inspections have to be captured as they happen, because a claim that cannot be evidenced afterwards is worth nothing at all.
The money arrives years later. A leg cured for three years ties up value for a very long time, so knowing what is hanging, from which animals and when it becomes sellable is a stock question and a cash flow question at once.