The high cost of commercial feed constrains pig production among smallholder farmers in sub-Saharan Africa. This pilot study evaluated three locally formulated diets in relation to growth performance, feed utilization efficiency, body condition, and behavioral responses of indigenous pigs in Jootar Town, Ukum Local Government Area, Benue State, Nigeria. Four indigenous growing pigs were assigned to four dietary treatments for eight weeks: a control diet (T1), a cassava peel-based diet (T2), a sorghum-based diet (T3), and a maize–millet-based diet (T4). Parameters assessed included body weight gain, average daily gain (ADG), feed intake, feed conversion ratio (FCR), body condition score, and behavioral indices. The pig receiving the maize–millet diet recorded the highest final body weight (31.4 kg), total weight gain (18.9 kg), and ADG (0.34 kg/day), alongside the most favorable FCR (4.12). The pig receiving the cassava peel-based diet exhibited lower growth performance, poorer feed efficiency (FCR = 6.33), reduced body condition, and increased aggressive behavior. Behavioral observations suggested greater stability and improved welfare among pigs receiving nutrient-dense diets. These preliminary findings suggest that maize–millet and sorghum-based diets may offer practical and potentially cost-effective feeding alternatives for indigenous pig production. However, the small pilot sample limits interpretation, and larger, replicated studies are required to validate these observations.