The efficiency of absorption of colostral immunoglobulins was evaluated in five Canchim and seven Nelore calves. They received colostrum pools with concentration of 70.20 ± 6.14 mg/mL through esofageal feeder at 2, 12, 24 and 36 hours after birth. The immunoglobulins concentrations of the pools were estimated through specific gravity and measured by radial immunodifusion. In the blood collection at birth and during the first 70 days of life, the total protein was assayed by biuret method and the immunoglobulins were assayed by radial immunodifusion. Data were analysed as a randomized split-plot statistical model. The highest concentrations of serum immunoglobulins and total protein were observed at 24 hours of age. No significant differences (P>0.5484) were observed for immunoglobulins concentration at 24 hours, with concentrations of 28.80 ± 7.24 mg/mL for Canchim and 27.32 ± 9.54 mg/mL for Nelore. The efficiency for immunoglobulins absorption was not significantly different (P>0.8715) between breeds, 64.04 ± 7.74% for Canchim and 62.30 ± 6.93% for Nelore. The lack of statistical significance persisted until the fourtieth day of life, period of maternal immunoglobulin predominance in the calves blood circulation. In the following period, from 40 to 70 days of age, phase of establishment of the endogenous production of immunoglobulin, differences in the IgG concentrations between the two groups were detected refflecting a possible breed effect difference. The process of colostral IgG absorption by the newborn calves was not affected by breed. The differences between breeds in the calves serum IgG were related to the phase of endogenous production of antibodies.
antibodies; colostrum; newborn calves; passive immunity
