To treat resistant Escherichia coli infection in chicks, Ampicillin was stabilized with a synthetic aluminum-magnesium silicate (AMS) to prolong its bioavailability. Its dose was also reduced to minimize adverse side effects. Vitamins A, C, E and Selenium levels in the chicks' feeds were increased to enhance immune response of the chicks. E. coli coloning forming units, per ml of bile of the chicks, treated with Ampicillin and with Ampicillin in AMS, were: 228800.00 ± 90103.50 and 134500.00 ± 44937.97 at 10 mg/kg, 104400.00 ± 36024.44 and 34800.00 ± 8014.97 at 7.5 mg/kg, 198400.00 ± 129301.80 and 156800.00 ± 109392.70 at 5 mg/kg. Mean bacterial loads of the untreated groups, fed normal feed and those fed the fortified feed were 824400.00 ± 322424.80 and 534800.00 ± 277832.80. At 7.5 mg/kg. Ampicillin in the AMS, effectively (P < 0.05) treated resistant E. coli infection in chicks, fed immunestimulants, with the infection rate reduced by 95.8%.