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.

Microbial inoculant and an extract of <i>Trichoderma longibrachiatum</i> with xylanase activity effect on chemical composition, fermentative profile and aerobic stability of guinea grass (<i>Pancium maximum</i> Jacq.) silage

“…growth and ammonia production (Xing et al, 2009;Tian et al, 2014). INO treatments decreased acetate and butyrate concentrations and were consistent with the results of Santos et al (2014). Low pH values often imply an increased lactic acid production, which reduces the production of other VFA and proteolysis in the silo (Muck, 1996).…”

“…In the current study, INO addition decreased pH, linearly increased the amounts of lactic acid bacteria and linearly decreased counts of mould and yeast in the silage, which likely prevented secondary fermentation processes. Santos et al (2014) inoculated guinea grass with a mixture of homofermentative lactic acid bacteria (LAB; containing L. plantarum, P. acidilactici and Enterococcus faecium) and reported a decrease in gas losses with a consequent increase of silage DM recovery. In addition, a synergetic effect of ENZ and INO8 combination on gas losses was noticed.…”

Effect of Genus and Growth Stage on the Chemical and Mineral Composition of Tropical Grasses Used to Feed Dairy Cows

“…In terms of nutritional value, tropical grasses can be affected by their growth stage; therefore, maturity is considered the most important factor affecting the chemical composition and nutritional quality of forages (Ribeiro et al, 2014). The nutritional value of forages linearly declines with increasing physiological maturity (Santos et al, 2014). As observed in this study, the increase in DM content with increasing maturity was expected.…”

“…The DM content of forages is important in calculating feed intake and improving milk production, but it is also important when farmers are interested in conserving this resource (i.e., silages). A DM content of 25% is recommended for minimizing effluent loss in silos and the preservation of nutrients in silages (Santos et al, 2014). In this study, grasses showed similar DM contents, showing their suitability for silage conservation.…”

Agronomic traits, chemical composition and silage quality of elephant grass fertilized with poultry litter

“…Grass silages can be improved by the use of other foods to increase the dry matter content and of compounds that favor fermentation and by the use of microbial inoculants (Santos et al, 2014;Brant et al, 2017).…”