The aim of this study was to evaluate the effects of replacement of Tifton-85 hay by maniçoba hay, in spineless cactus-based diets, on markers of energy, protein, mineral metabolism and serum enzyme activity of Moxotó goats. Sixteen uncastrated male Moxotó breed goats, with 20 months old and initial body weight of 21.7 ± 3.92 kg were used in a randomized blocks design, using the initial weight as the criterion for the formation of blocks, with two treatments and eight replicates per treatment. The experimental treatments consisted of two diets: diets containing Miúda spineless cactus associated with Tifton-85 hay (1) or maniçoba hay (2), with roughage:concentrate ratio of 70:30. Blood samples were collected fortnightly (baseline, 15 days, 30 days and 45 days) during the feedlot period. There was a higher serum concentration of total protein and fructosamine (P < 0.05) in goats that received maniçoba hay. However, there was higher serum gamma-glutamyl transferase (GGT) enzyme activity in goats that ingested Tifton-85 hay (P < 0.05). Concerning to the profile of blood metabolites in the different fortnightly collections, it was possible to verify a significant effect for urea, fructosamine, GGT enzyme activity, K and Cl levels (P < 0.05). In conclusion, Tifton-85 hay and maniçoba hay combined with spineless cactus does not cause metabolic disorders in feedlot native goats.