Abstract
This study aimed to evaluate the zootechnical performance of Oreochromis niloticus fed a formulated diet based on agricultural by-products and supplemented with probiotics. Three different treatments were administered to the fish: an industrial feed treatment (control), a formulated feed supplemented with probiotics (AAP), and a formulated feed without probiotics (ASP). Growth performance and welfare indicators were assessed. The results showed no significant differences among treatments for growth parameters, with mean daily weight gains of 61.24 ± 2.22 g (control), 62.1 g (AAP), and 69.51 ± 2.83 g (ASP). In contrast, among the welfare indicators, only the gonadosomatic index showed a significant difference among treatments. The highest value was recorded in fish receiving the probiotic-supplemented diet (1.12 ± 0.19%). These findings confirm the potential of agricultural by-products as cost-effective substitutes for industrial feeds, thereby helping to secure aquaculture feed supply. Combined with the use of probiotics, this approach effectively supports the physiological health of fish.