Antimicrobial growth promoters (AGPs) in animal production have been related to the increase in multidrug-resistant bacteria. The AGP ban in many countries has highlighted the growing need for alternatives for feed additives. Considering the non-antibiotic anti-inflammatory theory of AGPs, chicks received three different doses of sodium salicylate (SS) in feed (10, 30, 90 mg/kg), basal diet (BD) was used as a negative control, and zinc bacitracin (ZB) was used as a positive control. Chicks were individually housed to increase the accuracy of the dose of SS ingested. Performance parameters and footpad dermatitis were evaluated weekly, while haematology, serum biochemistry, histopathology, and tibial dyschondroplasia were determined on Days 21 and 42. A linear dose-dependent decrease in haemoglobin concentration was observed, but the values were within the normal reference range. Among all the other evaluated parameters, no relevant differences between treatments were observed; however, not even the AGP group performed better than the control group. It is possible that the conditions in which the birds were raised were not stressful enough to allow for anti-inflammatories to demonstrate their beneficial effects on performance. Studies should be conducted where the animals are exposed to commercial conditions, as the presence of natural stressors could allow a better evaluation of the efficacy of the anti-inflammatory agent as a growth promoter.

Antimicrobial Growth Promoters (AGPs) have been phased out due to their link to antibiotic resistance. While their exact mode of action remains unknown, they are thought to reduce inflammation in the gut. This study explored the safety and efficacy of two non-steroidal anti-inflammatory drugs (NSAIDs), ibuprofen (IBF) and meloxicam (MLX), as potential feed additives for broiler chickens. Chickens were divided into groups and fed diets supplemented with various doses of IBF or MLX for 42 days. Growth performance, blood parameters, and tissue health were monitored. While some minor changes in blood chemistry were observed, particularly a decrease in ALT levels and an increase in uric acid with IBF, these alterations were not considered clinically significant. Histopathological examination of vital organs revealed no signs of NSAID-induced damage. In conclusion, both IBF and MLX appear to be safe and well-tolerated as feed additives for broiler chickens, without negatively impacting growth performance or causing significant adverse effects.

The anti-inflammatory activity of antimicrobial growth promoters (AGPs) has been proposed as one mechanism contributing to their beneficial effects on broiler performance, raising interest in pharmacological modulation of inflammation as a non-antibiotic strategy. This proof-of-concept dose-escalation study evaluated the safety of prolonged dietary exposure to meloxicam (MLX) and explored its effects on performance. Seventy one-day-old male Cobb 500 broilers were allocated to five treatments (n = 14): basal diet (BD), BD supplemented with 55 ppm zinc bacitracin (ZB), or MLX at 0.4, 1.2, or 3.6 mg/kg body weight. Birds were monitored for 42 days, with growth performance, hematology, serum biochemistry, and histopathology evaluated. No consistent treatment-related hematological alterations occurred, and serum biochemistry was unaffected at day 21. At day 42, MLX produced dose-related changes in albumin, calculated globulin, and alanine aminotransferase, while alkaline phosphatase showed a quadratic response. Feed intake differed at selected time points, but MLX did not consistently alter growth performance. Performance also did not differ from the ZB. No apparent treatment-related patterns of histopathological lesions were identified in the birds examined. No overt toxicity was detected under the conditions and sample sizes evaluated, although selected biochemical responses at day 42 warrant further investigation. These preliminary findings support studies with defined inflammatory challenges and specific pharmacodynamic markers but do not establish the safety or growth-promoting efficacy of prolonged dietary MLX administration.