Substituição do milho pelo sorgo (Sorghum bicolor (L). Moench) em dietas extrusadas para a Tilápia do Nilo (Oreochromis niloticus)

Abstract

This research aims to evaluate the ability of sorghum to replace corn in extruded diets for Nile tilapia, evaluating its effects on performance, physiological, histological and metabolic responses. 480 juvenile Nile tilapia, with an average weight of 27g, were randomly distributed in 24 tanks of 250 liters, constituting a completely randomized design, with six treatments and four replications. The diets consisted of treatments T1 0%, T2 20%, T3 40%, T4 60%, T5 80%, T6 100%, corresponding to the levels of substitution. Zootechnical performance indices were analyzed; somatic indices HI; chemical composition of CQC substrate; complete blood count and biochemical parameters; digestive enzyme activity; hepatic and muscle metabolites: glycogen, AST and ALT, and proximal gut histomorphology. The replacement did not affect the performance, IH, CQC, blood count and hepatic glycogen; blood TRI and muscle glycogen were higher in T4 and T5 fish, hepatic AST enzymes in T4, T5, T6 fish and muscle enzymes in T3 fish were higher; muscle thickness was higher in T2 fish, villus perimeter was higher in T4 and T6 fish, villi height was higher in T2, T4 and T6 fish. The differences detected were not able to affect the performance and deregulate the metabolism of the fish. The set of responses observed allows us to affirm that sorghum is a potential substitute for corn in diets for the species, with no negative effects for Nile tilapia.