Effects of Additive Type on Fermentation and Aerobic Stability and Its Interaction with Air Exposure on Silage Nutritive Value

As farm profitability and sustainability of animal production are largely affected by overall losses of dry matter and nutritive value of silage from field to trough, the objective of the study was to assess the effects of different additive types on fermentation, aerobic stability (ASTA) and changes in in vitro organic matter digestibility (IVOMD) and metabolisable energy (ME) of grass and grass-clover silage exposed to air. Three trials were performed, where grass and grass-clover forages were treated with biological and chemical additives and ensiled in 1.6-L glass jars. Upon silo opening, fermentation characteristics, yeast counts and ASTA were determined as well as changes in IVOMD and ME during subsequent air exposure for up to 336 h. All silages were well preserved. The ASTA was improved byLactobacillus buchneri-containing additives in all trials and by chemical additives in trial 3. In untreated silage, aeration reduced IVOMD and ME but variable effects of additives were observed. The nutritive value was maintained throughout aeration by all additives in trial 1, whereas in trial 3, only chemical additives were successful. A strong negative linear relationship across trials was detected between the extent of aerobic deterioration and changes in ME during air exposure (r = -0.756,p< 0.001). Silage additives improving aerobic stability have the potential to prevent the loss of nutritive value of grass and grass-clover silage during feed-out

Effects of Chemical Additives on Whole-Crop Maize Silage Traits

Fungi-associated aerobic instability of maize silages occurs frequently under practical farming conditions. The use of heterofermentative lactic acid bacteria inoculants of the Lactobacillus buchneri-type has been demonstrated to improve stability of silages exposed to air (Kleinschmidt and Kung 2006) but is not a viable option if the silo is closed for less than 8 weeks, and for the treatment of the upper layers, which are particularly prone to deterioration due to lower compaction. In those cases, antimycotic chemicals must be applied of which sorbates, benzoates and propionates are most efficient against fungi (Auerbach 1996; Woolford 1975). However, as commercial chemical silage additives differ in composition and concentrations of individual active ingredients it is difficult to directly compare their efficacy. Therefore, this study aimed at investigating the effects of two chemical additives of different compositions and varying application rates on whole-crop maize silage traits. The parameter ‘sodium benzoate equivalents’ was employed to enable the direct comparison in terms of efficacy regardless of the specific composition of the additives

Novel Results on the Formation of Volatile Organic Compounds (VOC) in Silages

The incidence of volatile organic compounds, including ethyl esters of lactic and acetic acids, in grass silages was evaluated based on a total of 620 samples from 10 different lab-scale ensiling experiments. These substances were detected after cold-water extraction by gas-chromatography. The correlations between ethanol and esters concentrations varied greatly depending on the trial. It was shown that ethanol concentration and pH of the silages affected ester formation. Low silage pH stimulated ester accumulation. Up to pH of 4.3, a stronger relationship between ethanol and esters contents was found than in grass silages having higher pH values. By allocating the silages to different ethanol classes it was shown that at up to 10 g/kg DM, the correlation between pH and total ester content was very weak (rS = -0.22). At \u3e 10 g ethanol per kg DM, there was a strong negative relationship between the two tested parameters (rS = -0.82). Based on all available data (n = 1148) from different types of silages, a generally valid model is proposed to predict total ester concentrations (y) as a function of ethanol content (x): y = 114x (R2 = 0.76). It is recommended to use silage additives with proven record of reducing ethanol in silages, thereby minimizing the production of ethyl esters and excluding the potential negative effects of volatiles on feed intake

Considerations on Sampling and Statistical Analysis in Grassland Ensiling Trials

Critical findings on design, statistical analysis, and interpretation of the results will be addressed based on comparative ensiling trials. For this aim, a lab-scale ensiling trial on biostatistical issues was conducted in 2021. Grass material from a permanent mowing pasture was taken from (i) 10 sampling points, (ii) one sampling point, (iii) a mixture of 10 sampling points. For each sub-trial (based on the sampling design), 3 levels of the fixed treatment factor silage additive were tested with 10 replicates (without additive, chemical silage additive, biological silage additive). The analysis was performed within a linear mixed effects model (LMM) as randomized complete block design (RCBD), accounting for systematic effects of field sampling points (i) and/or time processing (i, ii, iii). In sub- trial (i), variability in trait values was highest and more influenced by treatments (variance heterogeneity), and block effects were most pronounced. In contrast, the block effect was less pronounced in (ii) and (iii), and we could not find a time gradient in the silage trait values. Depending on the nature of the silage trait (distribution, treatment variances), a suitable analysis procedure has to be chosen. The frequently used low number of replications is probably not sufficient

The Influence of Delayed Sealing and Repeated Air Ingress during the Storage of Maize Silage on Fermentation Patterns, Yeast Development and Aerobic Stability

This study investigates the effects of delayed sealing and repeated air ingress on the formation of primary fermentation products and other volatile organic compounds (VOC), the development of yeasts and the aerobic stability (ASTA) of maize (26.8% dry matter, DM). After packing, the silos were sealed either promptly or with a delay of 24 h, with repeated air ingress after 27, 55 and 135 days of storage. Losses of DM, fermentation pattern, including VOC, yeast numbers and aerobic stability, were determined 6 times during storage for 142 days. Yeast numbers markedly increased during the first three fermentation days, with the effect being much stronger in silage sealed with a delay than in promptly sealed silage (log10 cfu/g FM 7.27 vs. 5.88, p < 0.002). Simultaneously, the concentrations of ethanol and ethyl esters and DM losses increased. The DM losses were closely correlated with the total concentrations of alcohols and acetic acid (delay: R2 = 0.71, p < 0.001; prompt: R2 = 0.91, p < 0.001, respectively). The repeated air ingress for 24 h during storage after completion of the main fermentation phase had only a minor effect on fermentation pattern, VOC formation and DM losses. The relationship between the counts of total yeasts and lactate-assimilating yeasts (LAY) was very strong (R2 = 0.995, p < 0.001), and LAY numbers were shown to be largely responsible for aerobic instability (R2 = 0.752, p < 0.001). This trial proved the detrimental effects of air on silage fermentation with delayed sealing to be much more deleterious than repeated short-term air ingress after about one month of storage.Peer Reviewe

Quality of Baled Grass-Clover Silage as Affected by Additives and Harvest Methods

Previous studies have shown increased loading and ensiling capacities with a rotor cutter wagon compared to a precision chopping wagon with no effects on silage fermentation (Arvidsson and Lingvall 2005; Lingvall and Knicky 2008). However, to our knowledge, there are no studies on the effects of different mowing techniques in combination with chopping/cutting of the forage at harvest when the forage is ensiled with different types of additives. The aim of this experiment was to investigate the effects of mowing method, chopping vs. cutting of the forage, types of additives and their interactions on grass-clover silage quality

Recent results on heavy-ion induced reactions of interest for neutrinoless double beta decay at INFN-LNS

Abstract. The possibility to use a special class of heavy-ion induced direct reactions, such as double charge exchange reactions, is discussed in view of their application to extract information that may be helpful to determinate the nuclear matrix elements entering in the expression of neutrinoless double beta decay halflife. The methodology of the experimental campaign presently running at INFN - Laboratori Nazionali del Sud is reported and the experimental challenges characterizing such activity are describe