A plant for manufacturing long-fiber legume hay (F)- and grass hay (F)- based feed pellets (C) for zootechnical use, which comprises loading means (2) for loading predetermined amounts (D, D) of the hays (F, F), processing means (3) for processing the hays (F, F), in view of reducing the length (I) of the fibers to a predetermined average value (IM), mixing means (4) for mixing the reduced hays (F, F) with predetermined amounts (D-^D-T+D-Γ D2) of binders (L) and nutritional additives (A) to obtain a dough ( I). The plant includes forming means (1 0) for forming the dough ( I), which have a collection chamber (1 1 ), a forming die (1 2) communicating with the collection chamber (1 1 ) and having at least one extrusion passage (1 6), a pushing element (14), held within the collection chamber (1 1 ) and adapted to promote feeding of the dough (I) toward said at least one passage (1 6), an extruder element (1 5) located downstream from the pushing element (14) and adapted to move in the collection chamber (1 1 ) to cyclically push predetermined amounts (H) of dough ( I) into the passage and form a stratified bead (B) of dough ( I), breaking means (30) for breaking the bead (B), located downstream from the passage (16), to form stratified feed pellets (C). A method of manufacturing long-fiber feed pellets (C) for zootechnical use.Linvention concerne une installation destinée à la fabrication de granulés dalimentation (C) à fibres longues à base de foin de légumineuses (F) et de foin de graminées (F) destinés à un usage zootechnique, qui comporte des moyens de chargement (2) afin de charger des quantités prédéterminées (D, D) des foins (F, F), des moyens de traitement (3) afin de traiter les foins (F, F) en vue de réduire la longueur (I) des fibres à une valeur moyenne prédéterminée (IM), des moyens de mélange (4) afin de mélanger les foins réduits (F, F) à des quantités prédéterminées (D-^D-T+D-Γ D2) de liants (L) et dadditifs nutritionnels (A) pour obtenir une pâte ( I)
