दोहनकालमतिक्रामतस्तत्फलहानं दण्डः ॥ कZ_०२.२९.३३ ॥
dohanakālamatikrāmatastatphalahānaṃ daṇḍaḥ
If one exceeds/violates the prescribed milking time, the penalty is forfeiture of the resulting produce/benefit.
It is an economic sanction (loss of gains) designed to neutralize incentive for rule-breaking and is administratively easier to apply.