वत्सो वृषो धेनुश्चैषामवध्याः ॥ कZ_०२.२६.१० ॥
vatso vṛṣo dhenuś ca eṣām avadhyāḥ
Among these, the calf, the bull, and the milch-cow are not to be killed.
They are productive capital (breeding, traction, milk). Protecting them safeguards agrarian output, revenue stability, and food security.