Nutritional, antinutritional, and heavy metal profiles of ethnopoultry botanicals in Central Uganda.

In Central Uganda, smallholder farmers rely on indigenous ethnoveterinary botanicals as phytogenic feed additives (PFAs) for indigenous chickens (Gallus gallus domesticus). However, the balance between their nutritional benefits and toxicological risks remains poorly characterized. Following an ethnoveterinary survey in Najjembe sub-county where Capsicum frutescens (ranked 2nd ), Cannabis sativa (3rd ), and Nicotiana tabacum (4th) were prioritized by farmers, this study investigated their nutritional and safety profiles. Aloe vera (1st ) was excluded from analysis due to extensive prior documentation. Samples were analyzed for proximate, mineral, and antioxidant profiles using AOAC Official Methods. Antinutrients (tannins, oxalates, phytates) and heavy metals (Pb, Cd) were quantified using vanillin-HCl spectrophotometry and Atomic Absorption Spectrophotometry, respectively. Results showed significant nutritional variation among species (p < 0.05). C. sativa contained the highest crude protein (22.20 ± 1.1%) and was exceptionally rich in calcium and potassium. C. frutescens exhibited the highest caloric density (452.9 kcal/100 g) and antioxidant activity (IC50 = 11.78 mg/mL). Conversely, N. tabacum had the highest iron and magnesium but also the highest antinutrient concentrations. Critically, lead (Pb) and cadmium (Cd) levels in N. tabacum and C. sativa significantly exceeded FAO/WHO safety limits (Pb > 0.3 mg/kg), resulting in hazard indices (HI > 1.0), signaling potential health risks for chickens and consumers. While these plants offer high nutraceutical value, the heavy metal bioaccumulation in N. tabacum and C. sativa necessitates strict inclusion limits and processing to ensure food safety. C. frutescens is recommended as the most viable PFA for feed integration.