Untreated Barley Straw Research Articles

A zero-waste one step method to produce carboxy nanocellulose from the untreated barley and wheat straws

A zero-waste simple method was developed to produce carboxy nanocellulose directly from the untreated barley and wheat straw by treating with nitric acid (55%) and sodium nitrite at 40 °C for 12 h. This method significantly reduced the need for toxic chemicals such as TEMPO ((2,2,6,6-tetramethylpiperidin-1-yl)-oxyl) and radical generating chemicals. The process also reduced the usage of corrosive bases and acids and energy demand during the pretreatment process for the multi-step acid hydrolysis of biomass. Moreover, the by-product can be easily neutralized with the addition of NaOH, and the neutralized solution can be concentrated to obtain sodium nitrate which can be utilized as a fertilizer. The current method produces rod shaped and spherical particles of carboxy nanocellulose from the barley and wheat straw respectively with lower crystallinity (ca. ⁓30% of crystallinity index) than the barley and wheat straw itself (ca. ⁓60% of crystallinity index) as evidenced from the grazing incidence X-ray diffraction (GIXRD) technique. The conductometric titration revealed a high concentration (ca. ⁓2.6 mmol/g) of surface carboxylic (-COOH) acid groups and this result is supported by the high zeta potential value (ca ⁓-40mV) for the synthesized carboxy nanocellulose.

Techno-Economic Analysis of ZnO Nanoparticles Pretreatments for Biogas Production from Barley Straw

The aim of this study was to analyze the effect of ZnO nanoparticles (ZnO NPs) on the biogas production from mechanically treated barley straw and to perform a techno-economic analysis based on the costs assessment and on the results of biogas production. The structural changes of mechanically pretreated barley straw were observed using FTIR, XRD, TGA, and SEM. Additionally, both green ZnO NPs prepared from red alga (Antithamnion plumula) extract and chemically prepared ZnO NPs were characterized by FTIR, XRD, SEM, and TEM, surface area, and EDX. The results revealed that the biogas production was slightly improved by 14.9 and 13.2% when the barley straw of 0.4 mm was mechanically pretreated with 10 mg/L of both green and chemical ZnO NPs and produced 390.5 mL biogas/g VS and 385 mL biogas/g VS, respectively. On the other hand, the higher concentrations of ZnO NPs equal to 20 mg/L had an inhibitory effect on biogas production and decreased the biogas yield to 173 mL biogas/g VS, which was less than the half of previous values. It was also clear that the mechanically treated barley straw of 0.4 mm size presented a higher biogas yield of about 340 mL/g VS, in comparison to 279 mL biogas/g VS of untreated biomass. The kinetic study showed that the first order, modified Gompertz and logistic function models had the best fit with the experimental data. The results showed that the nanoparticles (NPs) of the mechanically treated barely straw are a suitable source of biomass for biogas production, and its yields are higher than the untreated barley straw. The results of the cost-benefit analysis showed that the average levelized cost of energy (LCOE), adopting the best treatments (0.4 mm + 10 mg/L ZnO), is 0.21 €/kWh, which is not competitive with the other renewable energy systems in the Egyptian energy market.

Identification of novel enzymes to enhance the ruminal digestion of barley straw

Crude enzyme extracts typically contain a broad spectrum of enzyme activities, most of which are redundant to those naturally produced by the rumen microbiome. Identification of enzyme activities that are synergistic to those produced by the rumen microbiome could enable formulation of enzyme cocktails that improve fiber digestion in ruminants. Compared to untreated barley straw, Viscozyme® increased gas production, dry matter digestion (P < 0.01) and volatile fatty acid production (P < 0.001) in ruminal batch cultures. Fractionation of Viscozyme® by Blue Native PAGE and analyses using a microassay and mass-spectrometry revealed a GH74 endoglucanase, GH71 α-1,3-glucanase, GH5 mannanase, GH7 cellobiohydrolase, GH28 pectinase, and esterases from Viscozyme® contributed to enhanced saccharification of barley straw by rumen mix enzymes. Grouping of these identified activities with their carbohydrate active enzymes (CAZy) counterparts enabled selection of similar CAZymes for downstream production and screening. Mining of these specific activities from other biological systems could lead to high value enzyme formulations for ruminants.

Effect of biological Treatment of Barley Straw with Baker’s Yeast (Saccharomyces cerevisiae) on some productive performance of growing lambs.

ABSTRACTThis study was conducted at the farm of Ruminants Research Station, Office of AgriculturalResearch, Ministry of Agriculture, Abu Ghraib – Baghdad. The experiment continued for 56 days,in addition to 14 days as preliminary period from 11/10/2015 until 06/12/2016 to study the effect oftreating barley straw with baker’s yeast (Saccharomyces cerevisiae) on some productiveperformance of growing lambs. Ten Awassi lambs used in this experiment with average initial weightof 38±0.50 kg and age 8-9 months. Lambs divided randomly into two equal groups and kept inseparate individual pens. Lambs fed individually on a unified concentrate diet (2.5% of body weight),while, roughages offered ad libitum. Each group fed on roughages (barley straw), as follows:1. The first group fed untreated barley straw plus concentrate mixture and operated as control2. The second group fed barley straw treated with baker’s yeast (Saccharomyces cerevisiae) at rate0.5% (5 kg / tones).Animals weighed every two weeks before morning feeding. The digestibility experimentperformed in the seventh week. Rumen liquor collected at fifth week of the experiment at three times(before feeding, after three and six hours from feeding). Results showed different effects amongtreatments. The yeast not significantly affected the feed intake, average daily gain (15 – 28 d), invivo digestibility, and rumen fermentation (pH and NH3-N). Moreover, there was significant decrease(P <0.05) in daily weight gain during 29 - 42 d with baker’s yeast compared with control (107.14and 160.71g/d, respectively), while a significant increase (P <0.05) found in daily weight gain in the(1 – 14 d and 43 – 56 d) with baker’s yeast (103.57 and 178.57 g/d, respectively) compared withcontrol (48.33 and 142.86 g/d, respectively). We conclude that treatment with baker’s yeast notimproved feed conversion ratio, feed intake, intake of different nutrients, weight gains, digestibilityand rumen fermentation (pH and NH3-N concentration).

Effect of Biological Treatment of Barley Straw with Baker's Yeast (Saccharomyces Cerevisiae) on Some Productive Performance of Growing Lambs

ABSTRACTThis study was conducted at the farm of Ruminants Research Station, Office of AgriculturalResearch, Ministry of Agriculture, Abu Ghraib – Baghdad. The experiment continued for 56 days,in addition to 14 days as preliminary period from 11/10/2015 until 06/12/2016 to study the effect oftreating barley straw with baker’s yeast (Saccharomyces cerevisiae) on some productiveperformance of growing lambs. Ten Awassi lambs used in this experiment with average initial weightof 38±0.50 kg and age 8-9 months. Lambs divided randomly into two equal groups and kept inseparate individual pens. Lambs fed individually on a unified concentrate diet (2.5% of body weight),while, roughages offered ad libitum. Each group fed on roughages (barley straw), as follows:1. The first group fed untreated barley straw plus concentrate mixture and operated as control2. The second group fed barley straw treated with baker’s yeast (Saccharomyces cerevisiae) at rate0.5% (5 kg / tones).Animals weighed every two weeks before morning feeding. The digestibility experimentperformed in the seventh week. Rumen liquor collected at fifth week of the experiment at three times(before feeding, after three and six hours from feeding). Results showed different effects amongtreatments. The yeast not significantly affected the feed intake, average daily gain (15 – 28 d), invivo digestibility, and rumen fermentation (pH and NH3-N). Moreover, there was significant decrease(P <0.05) in daily weight gain during 29 - 42 d with baker’s yeast compared with control (107.14and 160.71g/d, respectively), while a significant increase (P <0.05) found in daily weight gain in the(1 – 14 d and 43 – 56 d) with baker’s yeast (103.57 and 178.57 g/d, respectively) compared withcontrol (48.33 and 142.86 g/d, respectively). We conclude that treatment with baker’s yeast notimproved feed conversion ratio, feed intake, intake of different nutrients, weight gains, digestibilityand rumen fermentation (pH and NH3-N concentration).

Fermentation of Ammonia Fiber Expansion Treated and Untreated Barley Straw in a Rumen Simulation Technique Using Rumen Inoculum from Cattle with Slow versus Fast Rate of Fiber Disappearance.

The purpose of this study was to determine the effect of rumen inoculum from heifers with fast vs. slow rate of in situ fiber digestion on the fermentation of complex versus easily digested fiber sources in the forms of untreated and Ammonia Fiber Expansion (AFEX) treated barley straw, respectively, using an artificial rumen simulation technique (Rusitec). In situ fiber digestion was measured in a previous study by incubating untreated barley straw in the rumen of 16 heifers fed a diet consisting of 700 g/kg barley straw and 300 g/kg concentrate. The two heifers with fastest rate of digestion (Fast ≥ 4.18% h-1) and the two heifers with the slowest rate of digestion (Slow ≤ 3.17% h-1) were chosen as inoculum donors for this study. Two Rusitec apparatuses each equipped with eight fermenters were used in a completely randomized block design with two blocks (apparatus) and four treatments in a 2 × 2 factorial arrangement of treatments (Fast or Slow rumen inoculum and untreated or AFEX treated straw). Fast rumen inoculum and AFEX straw both increased (P < 0.05) disappearance of dry matter (DMD), organic matter, true DMD, neutral detergent fiber, acid detergent fiber, and nitrogen (N) with an interactive effect between the two (P < 0.05). Fast rumen inoculum increased (P > 0.05) methane production per gram of digested material for both untreated and AFEX straw, and reduced (interaction, P < 0.05) acetate: propionate ratio for untreated straw. Greater relative populations of Ruminococcus albus (P < 0.05) and increased microbial N production (P = 0.045) were observed in Fast rumen inoculum. AFEX straw in Fast inoculum had greater total bacterial populations than Slow, but for untreated straw this result was reversed (interaction, P = 0.013). These findings indicate that differences in microbial populations in rumen fluid contribute to differences in the capacity of rumen inoculum to digest fiber.

Disintegration in the biogas sector – Technologies and effects

Pretreatment of organic material prior to anaerobic digestion is seen as an option to increase the overall efficiency of the process. An overview of physical, chemical, and biological disintegration (DT) of substrates in the biogas sector is given. The energy demands DT were surveyed. The technologies were evaluated by reference to the Technology Readiness Assessment Guide of the U.S. Department of Energy. The evaluation focuses on ligno-cellulosic substrates like straw. Data of a survey among biogas plant operators were analyzed regarding the prevalence of disintegration technology classes in Germany. Furthermore, biochemical methane potential tests were conducted in laboratory scale to determine the specific methane yields of un-/treated barley straw (thermal pressure hydrolysis (TPH)). A methane potential of 228mlCH4/gVS was measured for untreated barley straw; and of 251mlCH4/gVS for TPH-straw (190°C, 30min). The reaction rates in BMP were calculated between 0.0976 and 0.1443d−1.

COMPARISON OF DIFFERENT IONIC LIQUIDS PRETREATMENT FOR CORN STOVER ENZYMATIC SACCHARIFICATION

Recently, application of ionic liquids (ILs) has received much attention due to their special solvency properties as a promising method of pretreatment for lignocellulosic biomass. Easy recovery of ionic liquids, chemical stability, temperature stability, nonflammability, low vapor pressure, and wide liquidus range are among those unique properties. These solvents are also known as green solvents due to their low vapor pressure. The present study was set to compare the effect of five different ILs, namely, 1-ethyl-3-methylimidazolium acetate ([EMIM][Ac]), 1-butyl-3-methylimidazolium chloride ([BMIM][Cl]), 1-ethyl-3-methyl imidazolium diethyl phosphate ([EMIM][DEP]), 1-allyl-3-methylimidazolium chloride ([AMIM][Cl]), and 1-ethyl-3-methylimidazolium-hydrogen sulfate ([EMIM][HSO4]), on corn stover in a bioethanol production process. The performance of ILs was evaluated based on the change observed in chemical structure, crystallinity index, cellulose digestibility, and glucose release. Overall, [EMIM][Ac]-pretreated corn stover led to significantly higher saccharification, with cellulose digestibility reaching 69% after 72 hr, whereas digestibility of untreated barley straw was measured at only 21%.

Maximum Production of Fermentable Sugars from Barley Straw Using Optimized Soaking in Aqueous Ammonia (SAA) Pretreatment

Soaking in aqueous ammonia (SAA) pretreatment was investigated to improve enzymatic digestibility and consequently to increase total fermentable sugar production from barley straw. Various effects of pretreatment process parameters, such as reaction temperature, reaction time, solid:liquid ratio, and ammonia concentration, were evaluated, and the optimum conditions for two of the most important factors, reaction temperature and time were determined using response surface methodology. Optimized reaction conditions were 77.6 °C treatment temperature, 12.1 h. treatment time, 15 wt.% ammonia concentration, and 1:8 solid-to-liquid ratio, which gave a sugar recovery yield of 71.5 % (percent of theoretical sugar recovered from the untreated barley straw) with enzyme loading of 15 FPU/g-glucan. In the optimization of the SAA pretreatment process, ammonia concentration, reaction temperature, and reaction time were determined to be the most significant factors correlated to subsequent enzyme digestibility. Based on tested conditions exhibiting high sugar recovery yields of >60 %, it appeared that reaction temperature affected total fermentable sugar production more significantly than reaction time.

Objective Bayesian vs. least squares estimation for by-products degradability with different rumen fluids

The degradation kinetic curves of different by-products have been obtained. The considered by-products were lemon and several types of treated and untreated barley straw, and they were degraded by in vitro incubation with rumen fluid extracted from two herds of Murciano-Granadina goats, one of them fed alfalfa hay and the other one fed barley straw. The feeds were incubated at 39ºC for 12, 24, 36, 48 and 72 hours with each rumen fluid. The resulting fitted exponential-type degradation curves obtained with a frequentist statistical analysis were compared with those resulting from an objective Bayesian statistical analysis. The use of the objective Bayesian analysis smoothed the estimates of the frequentist fit using least squares, which did not suitably process the involved restrictions and avoided biologically unacceptable results. On the other hand, the rumen fluid from goats fed alfalfa hay fomented the greatest effective degradability and the degradabilities of the different by-products were also compared, with the result that the lemon by-product was the best degraded one under both statistical analyses. Key words: In vitro fermentation, by-product, degradation curve

Supplementing spineless cactus (Opuntia ficus-indica f. inermis) based diets with urea-treated straw or oldman saltbush (Atriplex nummularia). Effects on intake, digestion and sheep growth

Atriplex nummularia L. (atriplex) foliage and urea-treated straw have been used as nitrogen supplements for Barbarine lambs given Opuntia ficus-indica f. inermis (cactus) and their effects on feed intake, diet apparent digestibility, nitrogen balance and daily gain have been evaluated. Twenty-four lambs (mean live weight 19·9±2·79 kg) were randomly allocated to one of four experimental groups, groups 1–3 received freshly cut pads of cactus ad libitum. Group 1 was supplemented with 600 g untreated barley straw (C+US), while group 2 received 600 g urea-treated straw (C+UTS). Group 3 received 600 g untreated straw and 400 g atriplex (C+A). The amount of atriplex was calculated so that groups 2 and 3 receive iso-nitrogenous diets (i.e. C+UTS and C+A). Group 4 (US+BW) received a diet commonly offered to sheep by Tunisian smallholders, untreated straw ad libitum and 400 g of ground barley grain and wheat bran mixture (50[ratio ]50). A growth trial (60 days) followed by a digestibility trial (8 days) were performed in 1999. Irrespective of dietary treatment, cactus intake was high, averaging 500 g dry matter (DM)/day. It was not affected (P&gt;0·05) with N supplementation, as urea-treated straw or atriplex. Sheep fed cactus-containing diets drank considerably less (P&lt;0·001) water than those on the common diet (US+BW). Nitrogen provision improved significantly apparent digestibility of cactus-based diets. Urea treatment of straw increased content of digestible dry matter, organic matter, crude protein and cell wall (NDF) by 100, 100, 120 and 290 g/kg diet, respectively. There was a further increase when atriplex was provided instead of urea-treated straw. Nitrogen balance was positive across all dietary treatments but was improved when the nitrogen content of cactus-based diets was increased. Sheep fed on cactus and supplemented with atriplex retained the same amount of N as those fed the common diet (US+BW). The efficiency of microbial N production, estimated by the urinary excretion of allantoin, was improved (P&lt;0·05) with N supplementation of cactus-diets (5·7, 12·4 and 11·4 mg/kg digestible OM intake for diets C+US, C+UTS, C+A, respectively). The diet C+US covered maintenance requirements of the sheep (7·7 g of daily gain). Nitrogen supplementation of cactus-based diets raised the average daily gain of lambs. Indeed, sheep given C+UTS or C+A diets grew at a rate of 19·9 or 31·4 g/day, respectively. It is noteworthy to mention that C+A and US+BW diets had similar effect (P&gt;0·05) on sheep growth (31·4 and 39·7 g/day, respectively). It is concluded that cactus may be considered as an emergency feed and water source for sheep in arid and semi-arid zones. Nitrogen supplementation of cactus-based diets with urea-treated straw or atriplex foliage improved the feeding value of these diets and consequently sheep growth. A cactus-based diet, supplemented with atriplex, promoted similar growth in sheep as the commonly used diet (US+BW).

Histochemistry and UV-microspectrometry of cell walls of untreated and ammonia-treated barley straw

Histochemical staining reactions with acid phloroglucinol and ultraviolet (UV) absorption spectra of the individual cell walls in spring barley straw (Hordeum vulgare L.) were investigated in combination with spectrometric measurements of the dioxane-water soluble lignin. Changes in lignin structure of barley straw with ammonia treatment were also investigated. Parenchyma and metaxylem vessel walls in untreated straw stained red with acid phloroglucinol and had higher absorbances around 550 nm than did epidermis and sclerenchyma cell walls, being consistent with the λmax of coniferylaldehyde. Following a reductive treatment, the lignins isolated from untreated barley straw showed an increase in UV absorbance at 280 nm and a decrease in that around 320 nm. These regions in UV and IR absorption spectra are assigned to conjugated carbonyl groups as shown by the narrowing of the IR absorption band at 1660 cm−1, and this was consistent with the staining observation of the specific tissue walls. UV microspectrometry indicated that parenchyma cell walls were much less lignified tissues than metaxylem and protoxylem vessel walls and probably epidermal cell walls. The lignins isolated from untreated and ammonia-treated straw had similar values for empirical formulae of the C9 units, phenolic hydroxyl and methoxyl group contents, and molecular weight, although the lignin of ammonia-treated straw had a slightly higher contents of nitrogen and hydrogen. The IR bands of 1730–1680 cm−1 in ammonia-treated straw lignin also disappeared. Therefore, ammonia appeared to react with the carbon atoms of the propane side-chain. Key words: Ammonia treatment, barley straw, lignin distribution, lignin structure, staining with acid phloroglucinol, ultraviolet microspectrometry

Factors affecting degradation of barley straw in sacco and microbial activity in the rumen of cows fed fibre-rich diets: III. The amount of supplemental energy

A basic diet composed of 76.2% untreated barley straw +23.8% grass hay was given to three non-lactating cows at 90% of ad libitum intake; the diet was supplemented with fishmeal to make the ration up to 12% protein on dry matter basis, a mineral–vitamin mixture and either 1.5 kg; 3.0 kg or 4.5 kg of rolled barley/cow×day in a Latin Square design. The inclusion of rolled barley affected the degradability of DM, OM and individual components of the cell wall of barley straw incubated in nylon bags for up to 72 h. The higher the energy level of supplementation, the lower the digestion of the cell wall components. The amount of starch influenced rumen pH, ammonia and VFAs concentrations, ATP and protozoal numbers, but no treatment effect could be detected upon the outflow rate of liquid or particulate phases. The ATP and DNA concentrations found inside the nylon bags suggest the presence of an inactive or less active population towards the substrate after 24 h of incubation.

Factors affecting degradation of barley straw in sacco and microbial activity in the rumen of cows fed fibre-rich diets II: The level of supplemental fishmeal

A diet composed of 76.2% untreated barley straw + 23.8% rye grass hay was given to three nonlactating cows at 90% of ad libitum intake. The cows were supplemented via cannulae with three different levels of fishmeal in order to make the ration up to 8%, 10% and 14% crude protein on a dry-matter basis. Treatments were arranged in a Latin Square design. Nylon bags containing untreated barley straw were incubated in the rumen of the cows for up to 72 h. Degradability of dry matter, total organic matter and the individual components of the cell wall of barley straw were affected by the protein level of the diet. The inclusion of fishmeal to a level of 14% dietary protein produced the highest degradability of all parameters measured. The protein level also affected ammonia and total VFA concentrations; both fermentation products were highest in the treatment with the high fishmeal level. Rumen pH and rumen outflow rate of liquid and particulate phases were not affected by protein level. The ATP concentration found in the solid residue, remaining after removal of the liquid phase from the rumen content, increased with increasing fishmeal level, while ATP in the liquid phase remained unchanged. This indicates that, under the conditions of this study, fishmeal exerts its effects on the microbes intimately associated to the fibre, and not upon the whole microbial population. The microbial DNA concentration of digesta within nylon bags increased during the first 24 h of incubation and then decreased until the end of incubation, indicating a process of colonization and depletion of degradable substrates.

Differences in microbial fermentation of barley straw induced by its treatment with anhydrous ammonia

AbstractThe effect of ammonia treatment of straw on both the rumen environment and the extent of its microbial fermentation was studied. Four rumen cannulated sheep were randomly given 700 g/day of untreated straw plus urea (US), ammonia-treated straw (TS) and alfalfa hay (AH) in a change-over design with three periods. Rumen pH was lower and ammonia-nitrogen and total volatile fatty acid (VFA) concentrations were higher (P &lt; 0·001) with AH than with US or TS. With the straw diets, TS promoted a lower pH than US (P &lt; 0·05), but differences were less than 0·3 units and the mean pH was never below 6·5. There were no differences between the straw diets in ammonia-nitrogen or VFA concentration (P &gt; 0·05). When untreated barley straw (BS) and treated straw (TS) were incubated in situ disappearance of dry matter (dDM) at 12, 24 and 48 h (P &lt; 0·01) and neutral-detergent fibre (dNDF) at 48 h (P &lt; 0·001) were higher with TS. In vitro incubation showed a higher gas production with TS only after 36 h (P &lt; 0·05) whereas gas from BS fermentation was higher up to 14 h (P &lt; 0·05). Among diets, dDM, dNDF and gas production with US were numerically higher than with TS or AH throughout, although few significant differences were observed, except for a higher dDM at 12 (P &lt; 0·01) and 24 (P &lt; 0·10) h and a higher dNDF at 12 h (P &lt; 0·10). Particle-associated enzymes were extracted from BS and TS incubated in the rumen for 4, 8, 22 and 24 h. Results ofxylanase and cellulase activities support those of straw incubation, with a drop between 4 and 8 h in TS diet. The concentration of residual phenolics per unit of incubated straws after 12 and 24 h show that phenolics release to the media was higher with the TS diet. Daily changes of phenolic concentration into rumen liquid was also higher with TS than with US (P &lt; 0·001). The increased release of straw phenolics by ammoniation reduced the potential for rumen degradation of straw, mainly in the first hours of the fermentation period.

Effect of ammoniation or protein supplementation of barley straw on digestion and purine derivative excretion in sheep

AbstractAn experiment was conducted to examine the effect of ammonia treatment or soya-bean meal supplementation on rumen and lower tract digestion and urinary purine-derivative excretion in sheep given barley straw-based diets. Four wethers each fitted with simple rumen and duodenal cannulae were randomly allocated to four diets in a 4×4 Latin-square design. The diets were, untreated barley straw + molasses meal (diet 1), ammonia-treated barley straw + molasses meal (diet 2), untreated barley straw + soya-bean meal + molasses meal (diet 3) and ammonia-treated barley straw + soya-bean meal + molasses meal (diet 4). Dry-matter (DM) intake, total tract neutral- and acid-detergent fibre apparent digestibility and faecal nitrogen (N) output were higher for diets 2 and 4. Microbial protein yield, determined from total urinary purine-derivative excretion, was also high in sheep on diets 2 and 4. However, supplementation with soya-bean meal in diet 4 reduced DM and fibre digestion but increased intake and microbial synthesis. Despite the lower microbial protein synthesis for diet 3, total tract N digestion was high for the diet, an indication of higher nutrient absorption in the lower tract. The above results indicated that there was a substantial increase in rumen microbial N yield from ammoniated straw-based diets. However, not all the N was made available to the animals. Some of the microbial N absorbed in the lower tract may have been overestimated by the use of the purine derivative-microbial N evaluation method. On the other hand, when protein supplements were given the amount of microbial protein available to the ruminant through absorption in the lower tract may have been underestimated by urinary purine derivatives.

Effect of ammonia treatment or protein supplementation on rumination behaviour in sheep given barley straw

AbstractA study was conducted to compare the effects of ammoniation and protein supplementation of barley straw on rumination behaviour of sheep. Four wethers were allocated to four diets offered ad libitum in a 4 × 4 Latin-square design. The diets were, untreated barley straw + molasses meal (diet 1), untreated barley straw + soya-bean meal + molasses meal (diet 2), ammonia-treated barley straw + molasses meal (diet 3) and ammonia-treated barley straw + soya-bean meal + molasses meal (diet 4). Animals were kept in metabolism crates throughout each 16-day experimental period and allowed free access to water and a mineralized salt lick. The first 11 days of each period were for adaptation to the harnesses and diets while the last 5 days were used for rumination studies. Animals given diets 3 and 4 had slower eating rates compared with those given diets 1 and 2. Rumination index and duration of each rumination period was lower for sheep consuming diets 3 and 4 than for those on diets 1 and 2 but not significantly so (P &gt; 0·05). Rumination time per 100 g neutral-detergent fibre (NDF) intake was significantly lower (P &lt; 0·01) for diets containing ammoniated straw. Animals given ammoniated straw diets also regurgitated fewer boluses per unit NDF intake than did those on untreated straw diets. The results showed that increased intake and digestibility, which is usually associated with ammoniated straws, was due to sheep doing less work per unit of time to break down straw for digestion. In this way, potentially digestible tissues within a given amount of straw is more readily exposed. The foregoing suggests that ammonia treatment results in less rumination so that ruminants given ammonia-treated straw diets do less work ruminating.

In vivo digestibility of treated and untreated barley straw: results of direct and by-difference digestibility trials

A herd of 28 castrated adult male goats of the Murciano-Granadina breed was used to determine the direct and by-difference digestibility of untreated straw, straw treated with 4% urea and straw treated with 4% urea and 1% NaOH.In the four direct digestibility trials the diets consisted exclusively of alfalfa hay, untreated (with N supplementation), or treated straws. In the three by-difference digestibility trials we used alfalfa hay as a basic diet at a ratio of 50,50 and untreated or treated straw. Dry matter digestibility increased when the straw was treated (P < 0.001), but there were no differences (P < 0.05) between the methods for determining digestibility. An effect of methodology on crude protein digestibility (CPD) was found (P < 0.001) and the type of straw X methods interaction was also significant (P < 0.001). CPD was significantly greater in straw treated with urea (P < 0.001) than in straw treated with urea + NaOH or untreated straw. The digestibility of the straw fibrous fractions improved with the treatments. On calculating the by-difference digestibility of crude fibre (CF), it was noted that straw treated with urea + NaOH had higher (P < 0.01) digestibility coefficients than in the direct digestibility trial. The digestible organic matter (DOM) content of the straw improved (P < 0.001) with the treatments and was not affected (P < 0.05) by the method used to calculate the digestibility. However, in urea + NaOH-treated straw, the DOM content was lower (P < 0.05) when determined directly than when calculated by difference, due to associative effect. In general, a greater standard error was found when the digestibility was calculated by difference, but both techniques showed the effect of treatment on straw. However, in urea + NaOH-treated straw it is advisable that digestibility be calculated by difference, in order to avoid high concentrations of alkali from urea + NaOH-treated straw in the rumen.

The dacron bag technique for comparing rumen degradability of untreated and ammonia-treated barley straw – effect of particle size and degree of replication

SUMMARYSix rumen-fistulated steers were studied over six periods of 3 days at Reading University's Animal Production Research Unit. In each period, eight dacron bags comprising two replicates of the 22 factorial treatment set consisting of untreated and NH3-treated barley straw in chopped (12–54 mm) or ground (2·5 mm screen) form were placed in the rumen of each steer. Bags were left in the rumen for a given time which was one of the set 6, 9, 15, 24, 48, 72 h. Percentage dry matter (DM) disappearance from dacron bags was consistently higher for NH3-treated than untreated straw and higher for ground than chopped straw. Analysis of variance gave F ratios for period and steer which were non-significant but of similar size, showing that using fewer animals could be compensated for by using more periods. Percentage DM disappearance as a function of time was well described by the model y = a — beet. The parameter defining rate of disappearance c, was similar for the four forms of straw. Differences between straws occurred in values of a (potential degradability) and b suggesting that physical form of material put into dacron bags needs standardizing if absolute values of a are to be used (e.g. for predicting roughage intake). Experimental designs need further research.

Effects of Energy Supplementation of Ammoniated Barley Straw on Performance of Cull Beef Cows

Feed value and performance of ruminants fed small grain straws are improved when these crop residues are chemically treated with anhydrous ammonia. Pelleted beet (Beta vulgaris (L.) subsp. vulgaris] pulp (high-fiber) and barley (Hordeum vulgare L.) grain (high-starch) energy supplementation of ammoniated straw diets may have differing effects on dry matter (DM) intake, DM digestibility, and animal performance. Thin cull beef cows (Bos taurus) (n = 96; average weight = 831 Ib ± 21; average condition score = 3.8 ± 0.2, scale 1 to 9) were allowed ad libitum access to untreated or ammoniated barley straw with or without energy supplementation for a 60 d feeding period