Specific immunoglobulins in serum of newborn lambs fed with a single dose of colostrum containing anti-peroxidase IgG

The apparent efficiency of absorption and the decrease of specific colostra l IgG after its passage into the blood stream were determined in newborn la mbs fed with a single dose of colostrum containing anti-peroxidase IgG at 3 0 minutes, 12 hours and 24 hours after birth. When colostrum was given at 3 0 minutes after birth, a value of 16.9 +/- 4.0 per cent of anti-peroxidase IgG ingested appeared in lamb circulation. This percentage was reduced to 9 .8 +/- 0.8 per cent when the feeding was done at 12 hours after birth and n o specific IgG was detected in lambs fed at 24 hours after birth. The conce ntration of anti-peroxidase IgG in lambs' serum declined quickly within 96 hours of age to about 48 per cent of the initial value, and afterwards the level decreased slowly reaching a value of 10 per cent at 32 days of age. T his behaviour probably reflects the protein distribution and use of absorbe d antiperoxidase IgG. (C) 2001 Harcourt Publishers Ltd.