Nutritive value of raketamena (Opuntia stricta) as a fodder in Madagascar

Abstract

Raketamena [Opuntia stricta (Haw.) Haw.] is considered a major invasive species in Madagascar. Problems related to this species include its invasiveness, losses to livestock, and health problems for humans consuming the fruits. Ideally, raketamena could be replaced by other, non-invasive cactus species. It is important, however, to identify potential ways to utilize raketamena in order to generate income for the local population during this replacement process. We collected fruit, cladode (mother and others), and root samples of raketamena in southern Madagascar in order to analyze its nutritive value and potential utilization as fodder. Samples were collected from five different plants and sun-dried. Plant components (cladodes from top 2/3 of the plant, mother-cladodes, fruits, and roots) were immersed (or not) in a hot-water treatment (60°C for 12 h). Samples were analyzed for crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), C, δ15N, and δ13C. On a dry-matter basis, roots represented 27% of total plant biomass, whereas cladodes represented 47% and fruits 26%. Roots and mother-cladodes presented 70.2 and 56.6% NDF and 45.7 and 34.8% ADF, respectively; both being potential fiber sources to supplement cactus diets. Cladodes had 39.7% NDF and 5.9% CP. Fruits presented a higher CP concentration (8.1%) and NDF of 67.6%. In general, immersion in heated water did not affect nutritive value, except for mature fruits. Preliminary results indicate the potential use of raketamena as fodder; however, further investigation to assess the performance of live animals feeding on raketamena is essential before any recommendation is made. Lessons learned on raketamena utilization will guide future programs for utilization of this species as a fodder in Madagascar.