Serum immunoglobulin concentration in response to maternal colostrum or colostral supplementation in dairy calves

Thirty-three Holstein calves were removed from their dams prior to nursing and were assigned alternately to 2 L of maternal colostrum with or without 125 g colostral replacer. Calves were fed after 0 h blood sample and 12 h later. Milk replacer was fed after 24 h (4 1/d). Blood was obtained as soon as possible after birth and at 12, 24, 48, and 72 h and at 28 and 56 d of age. Maternal colostrum, colostral replacer and serum were analyzed for IgG₁, IgG₂, and IgM by radial immunodiffusion. Serum Ig concentration did not differ (P > .10) among treatments and increased to 24 h. Total serum Ig and IgG₁ concentrations were affected by BW and intake of Ig, which accounted for 76 and 72% of variation in total Ig and IgG₁ respectively. Significant differences due to sex were found for IgG₂ and IgM without differences due to BW. Negative relationship between IgG₂ and IgM was observed. When calves were fed good quality colostrum (total Ig > 30 mg/ml), serum IgG₂ concentration tended to be greater in supplemented calves (P < .10), while serum IgM concentration was greater in calves fed maternal colostrum. Apparent efficiency of absorption of IgG₁ and IgM were higher in calves fed maternal colostrum than in supplemented calves (P < .10).