Microscopic and chemical changes during the first 22 days in Italian ryegrass and cocksfoot silages made in laboratory silos

Abstract

Although many aspects of grass silage have received intensive study, the changes that take place within the grass blades during ensilage have received little attention.In two factorial experiments Itahan ryegrass (cv. Lemtal) and cocksfoot (indigenous) were ensiled in laboratory silos (capacity 0-2 kg) with the grass under pressure (700 Pa) and subjected to two treatments (with or without 3-3 1 f 85% formic acid) and two silos from each treatment opened on eight sampling dates(l,2,3,4,7,10,14 and 21 d).For each sampling date transverse sections of grass laminae were examined and changes in the cross sections of the protoplasts and of cells, as defined by the cell walls, were recorded. These data were used to calculate the ratios of protoplast to cell volumes at each sampling date.Each silage was analysed for dry matter, pH, lactic acid, VFA, ammonia and glucose. The distance settled by the silage (a measure of decrease in silage volume) and the silage conductivity were also recorded.

Effects of plant species, stage of maturity, and level of formic acid addition on lipolysis, lipid content, and fatty acid composition during ensiling1

“…Formic acid application may result in more extensive cell membrane damage and, as a consequence, more extensive lipolysis during the ensilage of grass than that for RC. Formic acid addition is known to disrupt cell structure in grasses (Winters et al, 1987), but there are no reports for forage legumes, including RC.…”

The effect of cell wall degrading enzymes on the preservation of grass and on the silage intake and digestibility in sheep

“…In contrast, no increase in the volume of effluent with enzymes was found by Brolly (1986) with lucerne and Kennedy (1987) with grass silage. Likewise enzyme treatment, FA releases cell sap by penetrating beyond the epicuticular layer into the tissue and by disrupting mesophyll cell membranes (Winters et al 1987). The reaction is beneficial for rapid fermentation but leads to increased effluent formation with high moisture grasses (Pedersen et al 1973; Bastiman 1976).…”

Fermentative and microbiological profile of marandu-grass ensiled with citrus pulp pellets

“…However, many authors evaluating silages made from different crops have reported initial populations from 3.7 to 6.3 log CFU g -1 of silage with good conservation of ensilaged forage (Higginbotham et al, 1998;Driehuis et al, 2001;Whiter & Kung Jr., 2001). Considering our data, population size of lactic-acid bacteria at the beginning of ensilage was not enough for an effective production of lactic acid, but from the first day of fermentation, this microorganism population increased enough to promote a fast silage acidification.…”

“…However, during the initial phase of the ensilage process vegetal cell enzymes are capable to disrupt the cell structure to turn the nutrients required for fermentation available (Winters et al, 1987 andChamberlain, 1987). In studies with Italian ryegrass (Lolium multiflorum), after 6-7 days of ensilage an increase of 30% in the soluble carbohydrate level was observed due to ruptures of chemical bonds within structural carbohydrates, mainly hemicellulose (Chamberlain, 1987).…”