The weight and sex subdivisions — such as females weighing 200 kg to under 320 kg (0102390058) and males or females at or above 320 kg (0102390082, 0102390084) — reflect tariff-rate-quota structures that apply different duty rates depending on the animal's size category. Importers must weigh animals accurately and document sex to ensure correct line-level classification and to determine whether a shipment falls within or above any applicable quota threshold.

For HTS purposes, American bison (Bison bison) has its own dedicated line (0102390010) within this heading, while water buffalo and other non-purebred buffalo fall into the weight- and sex-segmented lines or the NESOI line. The distinction matters because APHIS health protocols and any applicable quota treatment may differ between bison and water buffalo. Importers should identify the species precisely on entry documentation rather than using the terms interchangeably.