Different dry matters content used for the conservation of annual ryegrass (Lolium multiflorum Lam.) in anaerobic environment

Annual ryegrass (Lolium multiflorum Lam.) is widely used for feeding ruminants, and the conservation of this material as haylage can be an alternative to farms. The aim of this work is to study the nutritional and microbiological value of annual ryegrass (L. multiflorum Lam.) pre-dried and stored with different dry matter contents (250, 350, 450, 550, 650 and 750 g kg-1) in anaerobic environment. The experimental design was completely randomized with six treatments and four replications. The pH presented at the time of opening of the silos showed a linear increase of 0.003 pH units for each 1 g kg-1 of dry matter increase in ryegrass, as the materials with contents above 550 g kg-1 of dry matter showed a pH above the desired pH. Materials containing 650 and 750 g kg-1 dry matter showed the lowest concentrations of NH3-N. This fact indicates that haylages with higher levels of dry matter present lower protein losses after aerobic exposure. The increase in dry matter contents of the treatments provided higher crude protein contents to the materials (being 112.91 g kg-1 of dry matter) in the treatment with 750 g kg-1 of dry matter. The best results for the proliferation of LABs and efficiency in pH decrease were in the treatment with 450 g kg-1 of dry matter. Key words: Haylage, chemical composition, Lolium multiflorum, silage, microorganism.