Effects of feeding colostrum, glucose or water on the first day of life on plasma immunoglobulin G concentrations and gamma-glutamyltransferase activities in calves.

Plasma immunoglobulin G (IgG) concentrations and gamma-glutamyltransferase (GGT) activities were measured in neonatal calves fed colostrum on days 1 and 2 of life, then milk up to day 7 (group C), while groups G and W were fed glucose or water, respectively, on day 1, colostrum on days 2 and 3 and milk up to day 7 of life. Glucose administration in group G on day 1 caused significantly more marked hyperglycaemias than in group C, while glucose concentrations in group W remained low. However, glucose concentrations on day 2 were significantly higher in group C than in groups G and W. Concentrations of IgG in group C significantly increased on day 1 and decreased after day 2, while GGT activity significantly increased after the first colostrum feeding only and decreased on day 2. Concentrations of IgG and GGT activity in groups G and W remained low on day 1 and increased on day 2. However, IgG remained significantly lower up to day 7 than in group C, while GGT reached the values of group C on day 2. Concentrations of IgG and activities of GGT on day 2 tended to increase less in group W than in group G. In conclusion, both plasma IgG concentration and GGT activity increased after colostrum intake, but only IgG remained elevated and thus informed on colostrum intake up to day 7. Intake of glucose relative to water did not significantly reduce the rise of IgG and GGT.