Neutral Detergent Solution Research Articles

A Study on Acid Hydrolysis and Composition of Polysaccharides Concentrated from Coconut Kernel

Defatted dehydrated coconut kernel powder (DDCP) is the by-product obtained from virgin coconut oil production through dry process. The aim of the study was to concentrate polysaccharides from DDCP and to investigate their acid hydrolysis capacity and the monosaccharides composition. Residual fat, protein and soluble sugars of DDCP were removed to concentrate coconut kernel Insoluble polysaccharides (CKIP) while water extract of DDCP was used to concentrate coconut kernel soluble polysaccharides (CKSP). Neutral detergent solution (NDS) was used to concentrate neutral detergent soluble polysaccharides (NDSP) and neutral detergent insoluble polysaccharides (NDIP) from CKIP. The acid detergent solution (ADS) was used to concentrate acid detergent soluble polysaccharides (ADSP) and acid detergent insoluble polysaccharides (ADIP) from CKIP. Results indicated fresh coconut kernel contained 7.2±1.5% carbohydrates and the content increased to 78.1±1.3% with the removal of residual fat, protein and sugars. The yields of the polysaccharide fractions were 46.0±3.1% (CKIP) and 9.2± 0.1% (CKSP), 10.2±0.3% (NDSP) and 78.3±4.2% (NDIP), 25.1±0.3% (ADSP) and 45.2±2.9% (ADIP). Trifluoracetic acid had a higher hydrolyzing capacity than sulphuric acid except for hydrolyzing of ADIP. The monosaccharides composition of the polysaccharides was significantly different (p<0.05) among the polysaccharide concentrates. The main monosaccharides in NDSP were glucose (73.86%) and xylose (19.7%) and, in ADSP were rhamnose (33.45%) and glucose (46.91%). Rhamnose (29.95%) arabinose (26.38%), xylose (21.56%) and mannose (12.87%) were present in CKSP while mannose (68.46%), galactose (20.59%) and xylose (10.59%) were present in CKIP. Results indicated that soluble polysaccharides of coconut kernel were hydrolyzed into monosaccharides readily compared to the insoluble polysaccharides.

Insights into Detoxification of Tolaasins, the Toxins Behind Mushroom Bacterial Blotch, by Microbacterium foliorum NBRC 103072T

Tolaasins are lipodepsipeptides secreted by Pseudomonas tolaasii, the causal agent of brown blotch disease of mushroom, and are the toxins that cause the brown spots. We previously reported that Microbacterium foliorum NBRC 103072T is an effective tolaasin-detoxifying bacterium. In this study, we aimed to characterize the tolaasin-detoxification process of M. foliorum NBRC 103072T. The tolaasin detoxification by M. foliorum NBRC 103072T was carried out by hydrolyzation of tolaasins at two specific sites in the peptide moiety of tolaasins by its cells, and the resulting fragments were released from bacterial cells. The tolaasin-hydrolyzing activity can be extracted by a neutral detergent solution from M. foliorum NBRC 103072T cells. Moreover, tolaasin adsorption to the bacterial cells occurred prior to hydrolyzation of tolaasins, which might contribute to the effective tolaasin detoxification by M. foliorum NBRC 103072T. It is notable that the tolaasin-degradation process by M. foliorum NBRC 103072T is carried out by hydrolyzation at specific sites in the peptide moiety of lipopeptide by bacterial cells as a novel biological degradation process of cyclic lipopeptides. [Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

175 The Suitability of Autoclave and Pressure Cooker Washing Methods in Comparison to ANKOM200 to Determine Neutral Detergent Fiber Using Different Feedstuffs and Washing Solutions

Abstract The use of the in vitro gas production (IVGP) technique requires accurate determination of neutral detergent fiber (NDF) residue. However, the NDF determination using standard procedures are not always feasible for IVGP; thus requiring micro-NDF methods, which need autoclave (AC) and pressure cooker (PC) to boil the solution. A complete randomized design using a 3×3 factorial arrangement was implemented to investigate the effect of washing methods (WM: AC, PC, or ANKOM200) and solution ratios (WS: 100 mL neutral detergent solution (ND), 150 mL ND, or 100 mL H2O/g sample) to determine NDF residues, assuming ANKOM200 and 100 mL ND/g as the standard methodology. Each factor combination was performed in triplicate with a replicate being comprised of 12 bottles or bags (two blanks and five feedstuffs in duplicate). Feedstuffs were: alfalfa hay (AH), bermudagrass hay (BH), two high-forage rations (G1 and G2), and a high-concentrate ration (FR). Following each run, bottles were filtered to obtain the NDF. Data were analyzed by diet using a random coefficients model. An interaction of WM ′ WS was present for AH and G1 (P < 0.01), G2 and FR had tendencies (P = 0.08 and 0.06, respectively), whereas BH demonstrated no interaction (P = 0.37). The PC with 100 mL or 150 mL did not differ from the standard methodology for AH, G1, G2, and FR. The BH demonstrated differences between WM and WS (P < 0.01). The PC had lower NDF residue compared to the AC and ANKOM200, whereas H2O had substantially greater NDF residue relative to both ND ratios. We concluded that H2O is not a suitable substitute for ND solution regardless of the feedstuff. Both micro-NDF washing methods may be satisfactory depending on the type of feedstuff used but further investigation is required.

176 The Suitability of Autoclave and Pressure Cooker Washing Methods in Comparison to ANKOM200 to Determine Neutral Detergent Fiber Using Different Feedstuffs and Washing Solutions

Abstract The use of the in vitro gas production (IVGP) technique requires accurate determination of neutral detergent fiber (NDF) residue. However, the NDF determination using standard procedures are not always feasible for IVGP; thus requiring micro-NDF methods, which need autoclave (AC) and pressure cooker (PC) to boil the solution. A complete randomized design using a 3×3 factorial arrangement was implemented to investigate the effect of washing methods (WM: AC, PC, or ANKOM200) and solution ratios (WS: 100 mL neutral detergent solution (ND), 150 mL ND, or 100 mL H2O/g sample) to determine NDF residues, assuming ANKOM200 and 100 mL ND/g as the standard methodology. Each factor combination was performed in triplicate with a replicate being comprised of 12 bottles or bags (two blanks and five feedstuffs in duplicate). Feedstuffs were: alfalfa hay (AH), bermudagrass hay (BH), two high-forage rations (G1 and G2), and a high-concentrate ration (FR). Following each run, bottles were filtered to obtain the NDF. Data were analyzed by diet using a random coefficients model. An interaction of WM ′ WS was present for AH and G1 (P < 0.01), G2 and FR had tendencies (P = 0.08 and 0.06, respectively), whereas BH demonstrated no interaction (P = 0.37). The PC with 100 mL or 150 mL did not differ from the standard methodology for AH, G1, G2, and FR. The BH demonstrated differences between WM and WS (P < 0.01). The PC had lower NDF residue compared to the AC and ANKOM200, whereas H2O had substantially greater NDF residue relative to both ND ratios. We concluded that H2O is not a suitable substitute for ND solution regardless of the feedstuff. Both micro-NDF washing methods may be satisfactory depending on the type of feedstuff used, but further investigation is required.

Use of Undigested NDF for Estimation of Diet Digestibility in Growing Pigs.

Simple SummaryKnowledge of diet digestibility in animals is essential to reduce feed costs and the amount of undigested nutrients excreted in the manure. Diet digestibility can be evaluated via in vivo, in situ (i.e., in the rumen of cannulated animals), and in vitro methods. The in vivo by total faecal collection methods and the in situ methods are expensive and ethically questionable. The in vitro methods are cheaper but also less accurate. This work aimed to verify whether the in vivo method with undigested neutral detergent fibre (uNDF), which is commonly used in ruminants as an internal marker, could be adapted toward growing pigs. Dry matter, organic matter, and neutral detergent fibre digestibilities estimated with the uNDF were compared with in vivo values determined by total faecal collection in a previous study. The effects of pre-treating samples with the neutral detergent solution and adding α-amylase were also tested to improve the repeatability and accuracy of the results. It was concluded that the estimation of diet digestibility with pre-treated uNDF as an internal marker in growing pigs could be an alternative to the total faecal collection method.Undigested neutral detergent fibre (uNDF) is commonly used as an internal marker for the estimation of diet digestibility in ruminants. This work aimed to verify (i) whether the in vivo method with uNDF could be used to evaluate diet digestibility in growing pigs, and (ii) whether pre-treating the samples with neutral detergent solution (NDS) and α-amylase improves the accuracy of the estimates. Samples from a previously published work of two diets with known in vivo digestibility values estimated by the total faecal collection method and 16 individual samples of faeces were used. For each sample, four Ankom F57 bags were weighed. Before the incubation, two F57 bags were pre-treated with NDS and α-amylase. All the samples were incubated for 240 h in the Ankom DaisyII incubator and then analysed for their uNDF contents. Dry matter, organic matter, and neutral detergent fibre digestibilities were estimated using the uNDF contents, and the results were compared with those of the former study. The digestibility values obtained using the uNDF method with pre-treatment were not statistically different from those determined with the total faecal collection. On the contrary, the uNDF method without the pre-treatment could not satisfactorily predict the digestibilities of pig diets.

Recycled utilization of Iris pseudacorus in constructed wetlands: Litters self-consumption and nitrogen removal improvement

Aquatic plants litters from constructed wetlands might become pollutants without proper treatment. Due to its high carbon and low nitrogen contained, Iris pseudacorus litters have potential to be used as carbon source to enhance denitrification process in advanced treatments of secondary effluent from wastewater treatment plants. This study investigated the characteristics of carbon release form Iris pseudacorus litters and its performance on enhancement of nitrogen removal. The batch experiment showed that the organic carbon release process can be simulated by combining dissolution and hydrolysis process, and it was found that dissolved organic matters mainly consisted of 60% sugar and 35% humic acid-like compounds from the neutral detergent solution and hemicellulose of litters. The long-term operation of lab-scale constructed wetlands revealed a high nitrogen removal of 78.81–90.39% in treating the synthetic wastewater treatment plants effluent with the equivalent dosage of 25–150 g litters m−2 d−1. Furthermore, it is possible to establish an Iris pseudacorus self-consumed constructed wetland to reuse all of the litters produced during the operation. These findings can contribute to the understanding of the dynamics of carbon release from Iris pseudacorus litters and recycled utilization of plant biomass in the constructed wetlands.

In vitro gas production including methane from bermudagrasses supplemented with dried distillers grains with solubles

The objective of this study was to document the simulated effect of dried distillers grains with solubles (DDGS) supplementation of Coastal bermudagrass (COS; Cynodon dactylon [L.] Pers.) and Tifton 85 bermudagrass (TIF; C. dactylon [L.] Pers. × Cynodon nlemfuënsis Vanderyst) forage on in vitro gas production, in vitro true digestibility (IVTD), in vitro NDF digestibility (IVNDFD), and methane production. Forage and DDGS were combined to represent 3 levels of supplemental DDGS (0, 0.25, or 1% BW), which resulted in ratios of forage:DDGS of 100:0, 87.5:12.5, and 50:50. Samples were incubated using the in vitro gas production technique, and headspace was sampled for quantification of methane concentration. The residue was rinsed in neutral detergent solution for determination of IVTD and IVNDFD. Discrete lag times of both the exponential and logistic equations decreased linearly (P < 0.01) with an increasing proportion of DDGS across TIF and COS. The IVTD of TIF (78% DM) was greater (P < 0.01) than for COS (71% DM), as was IVNDFD (66 vs. 54% NDF). Similarly, IVTD increased (P < 0.01) by 5% with 87.5:12.5 and by 19% with 50:50 across both COS and TIF. Methane production (g/kg of digestible DM and g/kg of digestible OM) decreased linearly (P ≤ 0.02) with an increasing proportion of DDGS for both COS and TIF. Results indicated that DDGS might be supplemented to cattle for increased diet digestibility with an additional potential benefit of reduced methane production. Efficacy of DDGS was dependent on forage nutritive value.

Effective sericin-fibroin separation from Bombyx mori silkworms fibers and low-cost salt removal from fibroin solution

Silk from Bombyx mori has two main proteins: fibroin and sericin. Fibroin is a protein that exhibits good biocompatibility and high surface reactivity, desirable properties for many biomedical applications. Sericin is related with adverse immune response in some medical uses. Therefore, its removal (degumming) is desirable in almost all fields, including the textile industry and biological applications. In this study, three degumming methods (distilled water, liquid neutral detergent and sodium carbonate solution) were evaluated using Raman spectroscopy. Degummed silk treated with sodium carbonate solution exhibits a pattern consistent with previous studies for sericin-free fibroin, and significant differences with the untreated silk pattern. Also, degummed fibroin fibers were dissolved in a calcium chloride solution, in pursuit of a more versatile material. Additionally, different porous membranes of dialysis tubes were tested to remove residual salts, and were compared by conductivity measurements and EDS analysis, identifying good performance for an affordable food cellulose membrane. The results showed that it is possible to obtain fibroin with adequate chemical properties, using low-cost process and membrane of dialysis tubes.

Corn silage rumen undegradable protein content and response of growing calves to rumen undegradable protein supplement.

The amount of rumen undegradable protein (RUP) in corn silage and the extent to which it is digested in the small intestine are uncertain. Three studies were conducted to determine RUP content of corn silage, and the effects of supplementing increasing concentrations of RUP on the growing performance of calves fed a corn silage diet. Experiments 1 and 2 used in situ methods to evaluate the RUP content of corn silage. In experiment 1, corn silages harvested at 37% or 42% dry matter (DM) were compared. In experiment 2, dry-rolled corn (89.4% DM) was reconstituted to 75%, 70%, 65%, and 50% DM and ensiled in mini-silos (2,265 cm3) for 30, 90, 180, or 270 d to simulate the corn grain within corn silage, dry-rolled corn is more mature than corn grain harvested in corn silage. Experiment 3 used 60 steers (275 kg initial body weight, SD = 18) in an 83-d growing study to evaluate the effects of supplementing 0.4%, 1.7%, 3.0%, 4.2%, or 5.5% RUP (% of diet DM) on performance. In experiment 1, RUP as a % of DM was not different between the two corn silages (P ≥ 0.12), averaging 0.59% for samples refluxed in a neutral detergent solution (NDS) and 1.8% for samples not refluxed in NDS. Dry matter digestibility (DMD) also did not differ (P ≥ 0.19), averaging 67.4%. In experiment 2, as moisture content of the corn grain increased, DMD increased linearly (P < 0.01) and RUP content decreased linearly (P < 0.01). The DMD increased quadratically (P = 0.02), whereas RUP content decreased linearly (P < 0.01) as days of ensiling increased. In experiment 3, there were no differences in DM intake (DMI; P ≥ 0.33) among treatments for period 1 (d 1 to 37). However, average daily gain (ADG) and gain-to-feed ratio (G:F) both linearly increased (P < 0.01) as RUP supplement inclusion increased. There were no differences in DMI (P ≥ 0.16), ADG (P ≥ 0.11), or G:F (P ≥ 0.64) in period 2 (d 38 to 83). For the overall growing period (d 1 to 83), a linear increase was observed for ending body weight (P = 0.01), ADG (P < 0.01), and G:F (P < 0.01) as RUP supplement inclusion increased from 0.4% to 5.5% of diet DM. The RUP content of corn silage is lower than previously reported. Data collected suggest the crude protein within corn silage is 13% RUP, and approximately 1/2 is digestible. The moisture content of corn silage at the time of harvest and the amount of time corn silage is stored continually impact protein availability. Supplementing growing calves fed corn silage with RUP will improve performance.

Extraction and Characterization of Oligosaccharides from Palm Kernel Cake as Prebiotic

The main objective of the present study was to extract and characterize oligosaccharides from palm kernel cake (OligoPKC) to be used as a prebiotic. Up to 16.81% of oligosaccharides were extracted from PKC using neutral detergent solution with two to eight degrees of polymerization. Molecular weights of seven fractions of OligoPKC were estimated using a mass spectrophotometer procedure resembling those of mannobiose, mannotriose, mannotetraose, mannopentaose, and mannohexaose standards, while those of two unknown components resembled those of heptasaccharide and octasaccharide. Enzymatic hydrolysis of OligoPKC using 11 enzymes showed that β-mannosidase and β-mannanase had the highest effects. OligoPKC fractions were potential substrates for growth of four species of Lactobacillus. Supplementation of OligoPKC in the diet of broiler chickens increased the population of beneficial microbes. However, it reduced the populations of pathogenic bacteria in the cecum. Hence, OligoPKC can be considered a potential prebiotic supplement in the feed and food industry.

Evaluation of Laboratory Procedures to Quantify the Neutral Detergent Fiber Content in Forage, Concentrate, and Ruminant Feces.

A comparison was made of measurements of neutral detergent fiber concentrations obtained with AOAC Method 2002.04 and modified methods using pressurized environments or direct use of industrial heat-stable α-amylase in samples of forage (n=37), concentrate (n=30), and ruminant feces (n=39). The following method modifications were tested: AOAC Method 2002.04 with replacement of the reflux apparatus with an autoclave or Ankom(220®) extractor and F57 filter bags, and AOAC Method 2002.04 with replacement of the standardization procedures for α-amylase by a single addition of industrial α-amylase [250 μL of Termamyl 2X 240 Kilo Novo Units (KNU)-T/g] prior to heating the neutral detergent solution. For the feces and forage samples, the results obtained with the modified methods with an autoclave or modification of α-amylase use were similar to those obtained using AOAC Method 2002.04, but the use of the Ankom220 extractor resulted in overestimated values. For the concentrate samples, the modified methods using an autoclave or Ankom220 extractor resulted in positive systematic errors. However, the method using industrial α-amylase resulted in systematic error and slope bias despite that the obtained values were close to those obtained with AOAC Method 2002.04.

Improvement and validation of the method to determine neutral detergent fiber in feed

To improve the performance of the analytical method for neutral detergent fiber in feed with heat-stable α-amylase treatment (aNDFom), the process of adding heat-stable α-amylase, as well as other analytical conditions, were examined. In this new process, the starch in the samples was removed by adding amylase to neutral detergent (ND) solution twice, just after the start of heating and immediately after refluxing. We also examined the effects of the use of sodium sulfite, and drying and ashing conditions for aNDFom analysis by this modified amylase addition method. A collaborative study to validate this new method was carried out with 15 laboratories. These laboratories analyzed two samples, alfalfa pellet and dairy mixed feed, with blind duplicates. Ten laboratories used a conventional apparatus and five used a Fibertec(®) type apparatus. There were no significant differences in aNDFom values between these two refluxing apparatuses. The aNDFom values in alfalfa pellet and dairy mixed feed were 388 g/kg and 145 g/kg, the coefficients of variation for the repeatability and reproducibility (CV(r) and CV(R) ) were 1.3% and 2.9%, and the HorRat values were 0.8 and 1.1, respectively. This new method was validated with 5.8% uncertainty (k = 2) from the collaborative study.

Evaluation of sodium sulfite and protein correction in analyses of fibrous compounds in tropical forages

The objective of this study was to evaluate the contents of fibrous compounds in tropical grasses and legumes according to utilization of sodium sulfite in the neutral detergent solution or using a procedure for contaminant protein correction. Samples of ten grasses and ten legumes were used. The contents of neutral detergent fiber were decreased when sodium sulfite was used; however, more prominent reductions were verified in legumes. Sodium sulfite decreased the acid detergent fiber content in both forage groups. The contents of neutral and acid detergent insoluble protein and lignin were reduced by sodium sulfite in legumes, but no effect was observed in grasses with regard to these variables. The decrease in fiber contents in legumes could be explained by the solubilization of lignin and decrease in insoluble nitrogen. However, the decreases in fiber in grasses could not be solely explained by the decrease in contaminant protein and solubilization of lignin, and loss of other fibrous compounds probably occurred. The utilization of sodium sulfite compromises the accuracy of the estimates of fibrous compounds contents in tropical forages. The precision of the estimates were not relevantly increased by sodium sulfite. The correction of insoluble fibrous compounds for protein is suggested instead of using sodium sulfite because there are no modifications on neutral detergent solution or undesirable solubilization of fibrous compounds.

Composition of structural carbohydrates in biomass: Precision of a liquid chromatography method using a neutral detergent extraction and a charged aerosol detector

We adapted and optimized a method to quantify the cellulose, hemicellulose, xylan, arabinan, mannan, galactan contents in lignocellulosic biomass. This method is based on a neutral detergent extraction (NDE) of the interfering biomass components, followed by a sulfuric acid hydrolysis (SAH) of the structural polysaccharides, and a liquid chromatography with charged aerosol detection (LC-CAD) to analyze the released monosaccharides. The first step of this NDE-SAH-LC-CAD method aims at removing all compounds that interfere with the subsequent sulphuric acid hydrolysis or with the subsequent chromatographic quantification of the cellulosic and hemicellulosic monosaccharides. This step includes starch hydrolysis with an analytical thermostable α-amylase followed by an extraction of soluble compounds by a Van Soest neutral detergent solution (NDE). The aim of this paper was to assess the precision of this method when choosing fiber sorghum (Sorghum bicolor (L.) Moench), tall fescue (Festuca arundinacea Schreb.) and fiber hemp (Cannabis sativa L.) as representative lignocellulosic biomass. The cellulose content of fiber sorghum, tall fescue and fiber hemp determined by the NDE-SAH-LC-CAD method were 28.7±1.0, 29.7±1.0 and 43.6±1.2g/100g dry matter, respectively, and their hemicellulose content were 18.6±0.5, 16.5±0.5 and 14.5±0.2g/100g dry matter, respectively. Cellulose, mannan and galactan contents were higher in fiber hemp (dicotyledon) as compared to tall fescue and fiber sorghum (monocotyledons). The xylan, arabinan and total hemicellulose contents were higher in tall fescue and fiber sorghum as compared to fiber hemp. The precision of the NDE-SAH-LC-CAD method was better for polysaccharide concentration levels above 1g/100g dry matter. Galactan analysis offered a lower precision, due to a lower CAD response intensity to galactose as compared to the other monosaccharides. The dispersions of the results (expanded uncertainty) of the NDE-SAH-LC-CAD method were smaller as compared to the Van Soest (VS) method. In addition, the NDE-SAH-LC-CAD method was able to provide additional information on the composition of the hemicellulose (xylan, arabinan, mannan and galactan content) that is not provided by the Van Soest method. The NDE-SAH-LC-CAD method offers also the advantage of a better specificity for hemicellulose and cellulose, as compared to the NREL and Uppsala methods.

Simulation of variations in the composition of samples in the evaluation of neutral detergent fiber contents by using cellulose standard in filter bags made from different textiles

The objective of this study was to evaluate the efficiency of using nylon textiles (50 μm), F57 (Ankom®) and non-woven textile (NWT - 100 g/m²) on laboratory evaluation of neutral detergent fiber (NDF) by using quantitative filter paper as purified cellulose standard and by simulating different composition of samples with additions of corn starch, pectin, casein and soybean oil. The quantitative filter paper was processed in a knife mill with a 1-mm screen sieve and the procedures for analyses of NDF contents were performed in a fiber analyzer (Ankom220®). Four experiments were carried out with additions of different ingredients into the filter paper: corn starch added at the levels of 15 or 50%; pectin, 15 or 50%; casein, 10 or 30%; and soybean oil at 0, 5, 10, 15, 25 or 50% of dry matter, respectively. The ratio 20 mg of dry matter/cm² of surface was followed. When it was relevant, in function of the evaluated treatments, heat-stable α-amylase was used. The use of F57 and NWT resulted in accurate estimates of NDF contents whereas nylon textile caused loss of insoluble fibrous particles, compromising accuracy of the results. For samples containing starch, use of heat-stable α-amylase is recommended in the evaluation of NDF contents. Pectin and casein are completely solubilized by neutral detergent solution. Levels of oil higher than 10% cause overestimation of NDF contents.

Effect of harvesting date on the composition and saccharification of Miscanthus x giganteus

The chemical composition of the whole aerial biomass and isolated organs of Miscanthus x giganteus was examined for saccharification into fermentable sugars at early and late harvesting dates. Delayed harvest was mainly related to increased amounts of cell wall and ester-linked phenolic acids. Addition of an enzyme cocktail (cellulases, β-glucosidase and xylanase) resulted in similar enzyme digestibilities at the two harvesting dates, ranging from 11–13% and 8–9% of the cellulose and arabinoxylan, respectively. However, the internodes, leaves and sheaths varied in cell wall content and composition and gave rise to different saccharification yields with internodes being the most recalcitrant organs . Non-cell wall fraction was estimated as the amount of material extracted by neutral detergent solution, and accounted for 23% of the whole aerial biomass harvested at an early date. However, saccharification yields from the miscanthus biomass did not change after soluble fraction removal . An ammonia pretreatment improved enzyme efficiency on early-harvested miscanthus, to a greater extent than on late-harvested biomass. This trend was confirmed for two different years of harvesting.

Qualitative and quantitative analysis of wood samples by Fourier transform infrared spectroscopy and multivariate analysis

Fourier transform infrared (FTIR) spectroscopy, in combination with multivariate analysis, enable the analysis of wood samples without time-consuming sample preparation. The aim of our work was to analysis the wood samples qualitatively and quantitatively by FTIR spectroscopy. A Van Soest method to determine the lignin, cellulose and hemicellulose content, was used as reference method. Multivariate calibration was performed based on first derivative of the FTIR spectra in the wave number range from 1900 to 800 cm −1, using principal component analysis (PCA), hierarchical cluster analysis (HCA) and partial least-squares (PLS) chemometric methods. Multivariate calibration models for FTIR spectroscopy have been developed. Using PCA and HCA approach, wood samples were classified as softwoods and hardwoods while wood samples with and without treatments were labeled as wood, neutral detergent solution fiber (NDSF), acid detergent solution fiber (ADSF) and strong acid solution fiber (SASF). Furthermore, PLS regression method was applied to correlate lignin, cellulose and hemicellulose contents in wood samples with the FTIR spectral data. The models’ refinement procedure and validation was performed by cross-validation. Although a wide range of input parameters (i.e., various wood species) was used, highly satisfactory results were obtained with the root-mean-square errors for the contents of lignin, cellulose and hemicellulose are 1.51, 0.96 and 0.62%, respectively. This study showed that FTIR spectra have the potential to be an important source of information for a quick evaluation of the chemical composition of wood samples.

Improved Feed Protein Fractionation Schemes for Formulating Rations with the Cornell Net Carbohydrate and Protein System

Adequate predictions of rumen-degradable protein (RDP) and rumen-undegradable protein (RUP) supplies are necessary to optimize performance while minimizing losses of excess nitrogen (N). The objectives of this study were to evaluate the original Cornell Net Carbohydrate Protein System (CNCPS) protein fractionation scheme and to develop and evaluate alternatives designed to improve its adequacy in predicting RDP and RUP. The CNCPS version 5 fractionates CP into 5 fractions based on solubility in protein precipitant agents, buffers, and detergent solutions: A represents the soluble nonprotein N, B1 is the soluble true protein, B2 represents protein with intermediate rates of degradation, B3 is the CP insoluble in neutral detergent solution but soluble in acid detergent solution, and C is the unavailable N. Model predictions were evaluated with studies that measured N flow data at the omasum. The N fractionation scheme in version 5 of the CNCPS explained 78% of the variation in RDP with a root mean square prediction error (RMSPE) of 275 g/d, and 51% of the RUP variation with RMSPE of 248 g/d. Neutral detergent insoluble CP flows were overpredicted with a mean bias of 128 g/d (40% of the observed mean). The greatest improvements in the accuracy of RDP and RUP predictions were obtained with the following 2 alternative schemes. Alternative 1 used the inhibitory in vitro system to measure the fractional rate of degradation for the insoluble protein fraction in which A = nonprotein N, B1 = true soluble protein, B2 = insoluble protein, C = unavailable protein (RDP: R2=0.84 and RMSPE = 167 g/d; RUP: R2=0.61 and RMSPE=209 g/d), whereas alternative 2 redefined A and B1 fractions as the non-amino-N and amino-N in the soluble fraction respectively (RDP: R2=0.79 with RMSPE=195 g/d and RUP: R2=0.54 with RMSPE=225 g/d). We concluded that implementing alternative 1 or 2 will improve the accuracy of predicting RDP and RUP within the CNCPS framework.

Influence of non-cellulose structural carbohydrate composition on plant material decomposition in soil

The C mineralisation pattern during the early stage of decomposition of plant materials is largely determined by their content of different carbohydrates. This study investigated whether detailed plant analysis could provide a better prediction of C mineralisation during decomposition than proximate analysis [neutral detergent solution (NDF)/acid detergent solution (ADF)]. The detailed analysis included sugars, fructans, starch, pectin, cellulose, lignin and organic N. To determine whether differences in decomposition rate were related to differences in hemicellulose composition, the analysis particularly emphasised the concentrations of arabinose and xylose in hemicelluloses. Carbon dioxide evolution was monitored hourly in soil amended with ten different plant materials. Principal component and regression analysis showed that C mineralisation during day 1 was closely related to free sugars, fructans and soluble organic N components (R2 = 0.83). The sum of non-cellulose structural carbohydrates (intermediate NDF/ADF fraction) was not related to C mineralisation between days 1 and 9. In contrast, a model including starch and protein in addition to the non-cellulose structural carbohydrates, with the hemicelluloses replaced by arabinose and xylose, showed a strong relationship with evolved CO2 (R2 = 0.87). Carbon mineralisation between days 9 and 34 was better explained by xylan, cellulose and lignin (R2 = 0.72) than by lignocellulose in the ADF fraction. Our results indicated that proximate analyses were not sufficient to explain differences in decomposition. To predict C mineralisation from the range of plant materials studied, we propose a minimum set of analyses comprising total N, free sugars, starch, arabinose, xylan, cellulose and lignin.

Relationship Between Chemical Component and In Vitro Digestibility of Tropical Grasses

Fifty samples of leaf and stem of Sorghum stipodeum, Themeda australis, Iseilema vaginiflorum, Brachyacne convergens, and Dicanthium fecundum with different stage of maturity were used to study the relationship between their chemical components and in vitro dry matter digestibility (IVDMD). The IVDMD was performed by two stage of digestion; the first stage was digestion in rumen inoculum and the second stage was digestion of protein using neutral detergent solution. The relationship between chemical components and IVDMD was analysed using regression method. There was a negative correlation between fiber component [neutral detergent fiber (NDF), acid detergent fiber (ADF), and lignin] and a positive correlation between water soluble extract (WSE) or crude protein with IVDMD. Water soluble extract was the best predictor of IVDMD with r = 0.71 and residual standard deviation of 8.4 unit. Since the method of WSE is simple and inexpensive, it can be used as a predictor of dry matter digestibility of most forages. Although there were large variation exist among the species, however, the stage of maturity was an important factor affecting IVDMD showed in four out of five species tested. In two of the five species measured, the IVDMD were higher in leaf than that in stem.