passages.id: split_1_test_3205_passage
passages.type: progene_text
passages.text: The milk sIL1R2 concentrations were 1.83 +/- 0.47 ng / ml ( colostrum ) , 0.73 +/- 0.22 ng / ml ( the early stage of lactation ) and 2.92 +/- 0.56 ng / ml ( the late stage of lactation ) .