Heifers averaged 27.78 months old at first calving, 43.11 months in second calving and 57.43 months in third calving.是什么意思_Heifers averaged 27.78 months old at first calving, 43.11 months in second calving and 57.43 months in third calving.在线翻译_英语_读音_用法_例句