Prosopis juliflora piperidine alkaloid extract levels in diet for sheep change energy and nitrogen metabolism and affect enteric methane yield.

BACKGROUND: Ionophore antibiotics improve the efficiency of energy metabolism, which has driven their use as a feed additive in ruminants for decades. Currently, they have not been approved in many countries, generating a challenge for the immediate search for plant extracts with a similar mode of action on rumen metabolism. This study evaluated the effects of enriched Prosopis juliflora (mesquite) piperidine alkaloid extract (MPA) levels as an alternative phytoadditive to sodium monensin (MON) in sheep. RESULTS: The MPA diet did not differ from MON with regard to nutrient intake. A quadratic effect (P < 0.05) was observed for organic matter and neutral detergent fibre digestibility, 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) faecal nitrogen loss. MPA did not differ from MON with regard to nutrient digestibility, and MPA levels increased (P < 0.05) the proportion of digestible energy and metabolizability from dietary gross energy. The MPA levels linearly decreased (P < 0.05) enteric CH4 production, the yield showing lower (P < 0.05) energy loss as CH4 than MON. CONCLUSION: 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 ruminants. © 2022 Society of Chemical Industry.

Effect of energy supplementation on intake, digestibility of diets and performance of grazing lambs during the rainy season.

This study aimed to evaluate different energy sources in multiple supplements on performance, intake, and digestibility of Santa Ines sheep grazing urochloa grass (Urochloa mosambicensis) during the rainy season. The experimental area was divided into seven paddocks of 4 ha each, with an average of dry matter (DM) availability of 3.21 tn/ha. A completely randomized design was carried out, in which there were four treatments, and each treatment was repeated six times. Twenty-four intact lambs (average: 32.0 kg of body weight) were supplemented with a mineral mixture, the control group (MM), mesquite pod meal (MPM), wheat bran (WB), or sorghum grain (SG) as energy sources. The digestibility of DM and crude protein (CP) in MPM and WB is higher than that in MM and SG groups. Neutral detergent fiber (NDF) digestibility was similar between supplemented lambs, and it was higher than the MM. The supplementation promoted higher weight gain than in the control group (0.126 vs. 0.061 g/day, respectively; P < 0.001). The supplementation increased the DM, and CP intake. The NDF intake only increased in the WB group. The CP digestibility was higher for the MPM and WB groups than that for MM and SG ones (P < 0.001). Sheep supplementation in the rainy season increased the average daily gain (ADG). Any supplement tested in the present study can be used during the rainy season. The choice for the supplement will depend on the availability and costs of the mesquite pod meal, sorghum grain, or wheat bran.