The effect of sodium selenite supplementation on monensin-induced growth inhibition and residue accumulation in broiler chicks.

Ninety-six commercial broiler chicks housed in battery brooders were exposed to experimental diets varying in monensin (50, 250 mg/kg) and sodium selenite (0, 10 mg/kg) levels from their 10th to 25th day of age. Feed and water were supplied ad libitum. There were 4 replications of each experimental treatment, each with 6 birds/replication. The data on bird weights showed a significant treatment effect for monensin, sodium selenite, and an interaction between the 2. High levels of monensin and sodium selenite decreased weight, the combination exacerbating this response. The residue data showed that chicks accumulated significantly higher concentrations of selenium in their tissues when on diets high in sodium selenite. Chicks also accumulated significantly higher concentrations of monensin in their tissues when on diets high in monensin. An interactive effect was observed in terms of the selenium residue data, high levels of dietary monensin decreased the selenium residue concentration in the liver, kidney and cardiac muscle tissues when on high sodium selenite diets. No interactive effect was observed in terms of the monensin residue data. Pathological lesions, which were expected but not observed, may also indicate an interaction between these compounds.