Effect of oxytetracycline as a turkey feed additive

Turkeys were given oxytetracycline (OTC) as a feed supplement at levels of 0 g, 50 g, and 200 g OTC per ton of feed. After 8, 16, and 18 weeks the birds were sacrificed and bacteria were isolated from heart blood and liver tissue. When these isolates were tested for resistance against eight antibiotics, a direct correlation was observed between the level of supplement and the level of antibiotic resistance in the bacterial isolates. In postmortem studies on the livers from birds consuming both levels of OTC, an increase in the occurrence of lesions was observed. The livers from control birds appeared to have more granulomas.