I wonder who is going to replace Kenji Utsumi since he recently passed away (or unless his part was already recorded, then Silver Spoon would be his last voice acting role)... The official website still got him on the cast list.
According to Japanese wikipedia - 生前最後の出演は2013年7月にスタートするテレビアニメ『銀の匙 Silver Spoon』の轟先生役であり、死去後に放送されるため、これが遺作となった。
It seems his part for Silver Spoon is already recorded... It'd be rather upsetting to listen to his parts in Silver Spoon ;A;This website
also said that Todoroki-sensei's part has been recorded.