title: Effect of regrowth interval and a microbial inoculant on the fermentation profile and dry matter recovery of guinea grass silages.
abstract: The objectives of this study were to characterize and quantify the microbial populations in guinea grass (Panicum maximum Jacq. cultivar Mombasa) harvested at different regrowth intervals (35, 45, 55, and 65 d). The chemical composition and fermentation profile of silages (after 60 d) with or without the addition of a microbial inoculant were also analyzed. Before ensiling, samples of the plants were used for the isolation and identification of lactic acid bacteria (LAB) in the epiphytic microbiota. A 4 × 2 factorial arrangement of treatments (4 regrowth intervals × with/without inoculant) was used in a completely randomized design with 3 replications. Based on the morphological and biochemical characteristics and the carbohydrate fermentation profile, Lactobacillus plantarum was found to be the predominant specie of LAB in guinea grass forage. Linear increases were detected in the dry matter (DM) content and concentrations of neutral detergent fiber, acid detergent fiber, acid detergent insoluble nitrogen, and DM recovery as well as linear reductions in the concentrations of crude protein and NH3-N with regrowth interval. Additionally, linear reductions for gas and effluent losses in silages were detected with increasing regrowth interval. These results demonstrate that guinea grass plants harvested after 55 d of regrowth contain a LAB population sufficiently large to ensure good fermentation and increase the DM recovery. The use of microbial inoculant further enhanced the fermentation of guinea grass at all stages of regrowth by improving the DM recovery.
authors.affiliation: Department of Animal Science, Federal University of Paraiba, Areia, 58397000, Brazil.
authors.forename: E M
authors.initials: EM
authors.lastname: Santos
authors.affiliation: Department of Animal Science, Federal University of Viçosa, Viçosa, 36570000, Brazil. Electronic address: odilon@ufv.br.
authors.forename: O G
authors.initials: OG
authors.lastname: Pereira
authors.affiliation: Department of Animal Science, Federal University of Viçosa, Viçosa, 36570000, Brazil.
authors.forename: R
authors.initials: R
authors.lastname: Garcia
authors.affiliation: Department of Food Technology, Federal University of Viçosa, Viçosa, 36570000, Brazil.
authors.forename: C L L F
authors.initials: CL
authors.lastname: Ferreira
authors.affiliation: Department of Animal Science, Federal University of Paraiba, Areia, 58397000, Brazil.
authors.forename: J S
authors.initials: JS
authors.lastname: Oliveira
authors.affiliation: Department of Animal Science, Federal University of Viçosa, Viçosa, 36570000, Brazil.
authors.forename: T C
authors.initials: TC
authors.lastname: Silva
mesh_terms: D059827:Agricultural Inoculants / Q000254:growth & development*; D001938:Brazil; D004043:Dietary Fiber / Q000032:analysis; D004044:Dietary Proteins / Q000032:analysis; D016984:Enterococcus faecium / Q000254:growth & development; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D007778:Lactobacillus / Q000254:growth & development; D048191:Lactiplantibacillus plantarum / Q000254:growth & development; D016014:Linear Models; D008897:Panicum / Q000382:microbiology*; D010376:Pediococcus / Q000254:growth & development; D012820:Silage / Q000032:analysis / Q000382:microbiology*
chemical_list: D004043:Dietary Fiber; D004044:Dietary Proteins
keywords: ammonia; crude protein; lactic acid bacteria; tropical grass