Abstract— This study aimed to evaluate levels of enriched mesquite piperidine alkaloid extract (MPA) comparison with sodium monensin on the nutrition and growth performance of goats fed diets with high concentrate content. Thirty Anglo-Nubian crossbred goats, 120 days of age, and initial body weight 21.82 ± 0.11 kg were distributed to the following diets: 0 (no additive), with MPA 9.2, 18.4, and 27.6 mg kg-1 or monensin (MON) 2.7 mg kg-1. The diets with MPA did not differ (P > 0.10) from the

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... diet for the intake and digestibility of DM and OM. However, NDFap and CP intake (g kg-1 BW0.75), MON showed a higher mean compared to MPA, and their digestibility coefficients did not differ. There was a linear increase (P < 0.05) for the intake and digestibility of CP and NFC with the MPA levels. The metabolizable energy (ME) and daily weight gain (DWG) presented a quadratic effect (P < 0.05) with peaks estimated at 17.4 and 14.8. There was no difference (P > 0.10) for microbial nitrogen synthesis, and microbial efficiency decreased linearly (P < 0.05) with the MPA levels, but MPA did not differ (P > 0.05) from the MON. Nitrogen retention (NR, g day-1) increased (P < 0.05) with the MPA levels due to the linear increase of N intake (NI) and digested nitrogen (DN). For the diet with 27.6 mg kg-1 MPA, the DWG decrease occurred due to the lower digestible energy intake and microbial protein synthesis efficiency.