Safety and growth-promoting potential of repeated administration of sodium salicylate to broilers

Antimicrobial growth promoters (AGPs) have been banned from animal husbandry owing to their association with the occurrence of bacterial resistance. Although the mechanism of action of AGP is still unknown, it is believed to be related to an anti-inflammatory action in the gastrointestinal tract. In this context, the aim of the present study was to establish if supplementation of broiler feed with the non-steroidal anti-inflammatory sodium salicylate (SS) induces adverse effects related to this class of drug and to evaluate the potentiality of SS in improving the zootechnical indices of broilers. One-day-old Cobb 500 male chicks were divided into four groups (12 per group) and treated over a period of 42 days with non-supplemented feed (control group) or with feed to which doses of 2.5, 5.0, or 10.0 mg of SS/kg BW were added daily. Feed intake and BW were assessed and haematological, biochemical, and histopathological alterations were evaluated throughout the experiment. Whereas no statistical differences in food intake or BW were detected between the groups, a 5.8% increase in total BW gain was observed in broilers treated with 10 mg of SS/kg BW. In addition, the highest dose of SS studied generated the lowest total feed conversion rate over the experimental period in comparison with all other SS treatment groups. Haematological and biochemical evaluations did not reveal any altered parameters that could be related to the adverse effects of SS. No renal or hepatic alterations were detected in the histopathological study of tissue collected on day 42, and no lesions or ulcerations were observed in the gastrointestinal tract. We conclude that daily doses of SS in the range of 2.5–10 mg/kg BW can be added safely to broiler feed for 42 days, and that this non-steroidal anti-inflammatory drug is promising for future studies of its use as a growth-promoting agent.