To the foreigner, trying to live according to western standards in Yokohama in 1872, life could be difficult. Everything for the household had to come from abroad, usually in cans and by sailing ship-flour from America, butter from Denmark, oil and dried vegetables and wines from France, mutton and game from China, potatoes and onions from California, coffee from Aden, et cetera. Meat, however, was available locally almost from the beginning. It was imported on the hoof from China and America and slaughtered at Honmoku.
"It was imported on the hoof" は、その後 "slaughtered" とあるので、牛や豚を生きたままで輸入していたの意味である事が分かります。慣用句らしい "on the hoof" を辞書で確認します。
・Collins English Dictionary: (of livestock) alive:
・Wiktionary: (of cattle) that has not yet been butchered
確かに、"on the hoof" が家畜の前の生きたままの状態を示している慣用句であることは確認できましたが、この慣用句はむしろ次ぎの意味で使われる事が多い様です。
・Collins English Dictionary: in an impromptu manner ⇒ he did his thinking on the hoof
・Cambridge English Dictionary: If you do something on the hoof, you do it while you are moving about or doing something else, often without giving it the attention it deserves: I've got a meeting downtown in 20 minutes so I'll have lunch on the hoof.