LAUSR

BACKGROUND Ionophores antibiotics improve the efficiency of energy metabolism that has driven its use for decades as a feed additive in ruminant. Currently, it has not been approved in many countries generating a challenge for the immediate search for plant extracts with similar mode of action on the rumen metabolism. This study evaluated the effects of enriched Prosopis juliflora (mesquite) piperidine alkaloid extract (MPA) levels as alternative phytoadditive to sodium monensin (MON) in sheep. RESULTS The MPA diet did not differ from MON for nutrient intake. A quadratic effect (P < 0.05) was observed for organic matter (OMD) and neutral detergent fibre digestibility (NDFD) with respective maximum point at 25.40 and minimum point at 0.95 mg kg-1 MPA. The MPA levels linearly decreased (P < 0.05) the faecal nitrogen loss. MPA did not differ from MON for nutrient digestibility, and the MPA levels increased (P < 0.05) the proportion of digestible energy and metabolisability from dietary gross energy. The MPA levels linearly decreased (P < 0.05) enteric CH4 production and yield showing lower (P < 0.05) energy loss as CH4 than MON. CONCLUSIONS The results show that MPA levels of 17.3 and 27.8 mg kg-1 are enteric CH4 inhibitors and enhance energy and protein utilization, indicating a promising alternative to MON for ruminant. This article is protected by copyright. All rights reserved.