Immunoglobulin levels in ewe colostrum and in lamb serum

The immunoglobulin content of ewe colostrum falls rapidly after the first suckling and reaches a low level 36 h after the first feed. The whey content of colostrum will rise by more than 50 per cent during the same period. The production of colostral immunoglobulin during the 24 h following the first feed was related, in this work, to the amount of colostrum produced; the greater the colostrum production, the greater the immunoglobulin production. Colostrum production ranged from 1216 to 4493 g and immunoglobulin production from 22-21 to 86-34 g during the eight feeds studied. Colostrum production was related to demand by the lambs. There was a clear positive correlation between the total amount of immunoglobulin the lambs' circulation 30 h after the first feed and the immunoglobulin consumed. Approximately 20 to 25 per cent of the immunoglobulin ingested was present in the lambs' circulation at this time.