The aim of this work is to study the biochemical and microbiological characterization of the prickly pear fruits abandoned in the fields after harvest in order to use it in the animal feed. This work reveal that the skin and pulp have a pH close to neutral (6.83 for the skin and 6.41 for the pulp), they are very rich in water (84.89% for the skin and 87.19% for the pulp), in sugars (31.19 % DM for the skin and 42.17 % DM for the pulp) and in mineral elements (13.7% DM for the skin and 4.46% DM for the pulp). They have average values in NDF, ADF, ADL, cellulose and hemicellulose fibers which values are respectively for the skin 11.72% DM, 7.75% DM, 1.25% DM, 3.98% DM, 6.5% DM and for the pulp 8.50% DM, 5.67% DM, 1.45% DM, 2.84% DM, 4.22% DM. The crude protein content is 4.84% DM for the skin and 10.2% DM for the pulp respectively remains low in comparison with other food by-products such as oilseed meal. The fat content is very low (0.09% DM for the skin and 0.17% DM for the pulp). As for the seeds, the results showed a low content of water (14.6%), mineral elements (1.99% DM), sugars (8.18 % DM) and crude proteins (7.66% DM), high fat contents ( 8.91% DM) and NDF, ADF, ADL, cellulose and hemicellulose fibers wish are respectively 78.18% DM, 62.99% DM, 42.94% DM, 15.19% DM, 20.05% DM. On the microbiological side, the results showed a significant load of microorganisms in this case molds and lactic bacteria which can be exploited in the recovery of these residues. The comparison between the three fractions of the cactus fruit showed that the seed is the richest in dry matter, fat and fiber, while the pulp is the richest in sugars, the skin when it is the richest in calcium.

Keywords : Cactus Fruit, Pulp, Skin, Seeds, Characterization, Biochemical, Chemical, Microbiological