The Chianina is both the tallest and the heaviest breed of cattle. Mature bulls stand up to , and oxen may reach . It is not unusual for bulls to exceed in weight. Males standing over at 12 months are considered top-grade. A Chianina bull named Donetto holds the world record for the heaviest bull, reported by one source as when exhibited at the Arezzo show in 1955, but as and tall at the age of 8 by others including the Tenuta La Fratta, near Sinalunga in the province of Siena, where he was bred. Cows usually weigh , but commonly exceed ; those standing over are judged top-grade. Calves routinely weigh over at birth.