Eighty six piglets born from a crossbread Landrace x Large White sows were assigned to four treatments using a randomized block design (4 blocks/treatment). Besides the control treatment (T4), two other treatments (T1 and T2) had powder milk incorporated to the rations (14.4% and 9.6% in the pre-initial phase and 9.6% and 4.8% in the initial phase). The fourth treatment (T3) did not have powder milk in the ration but diluted in water at 10%, only in the pre-initial phase. The pre-initial diet was used between 21 and 49 days of life and the initial in the period between 49 and 61 days of life. Blood samples were collected for serum immunoglobulin (Ig) determination at 1, 2, 10, 21, 28, 35 and 61 days of life. In the period 1 to 28 days the concentration of Ig in T4 was superior (p < 0,05), compared to the other treatments, while in the period 28 to 61 days, no difference was detected. This result reflects the influence of Ig acquisition from colostrum in this period. At day 21 the difference between T2 and T4 was significative. The lowest concentrations of Ig ocurred between 28 and 35 days in treatments T1, T3 and T4, and between 21 and 28 days in treatment T2. This result suggests that lower levels of Ig in the exogenous phase and catabolic phase of Ig adquired from colostrum, determine an earlier beginning of antibodies synthesis.
swine; passive immunity; powder milk