Digestibility Of Barley Straw Research Articles

Effect of Exogenous Fibrolytic Enzyme Application on the Microbial Attachment and Digestion of Barley Straw In vitro.

The effects of exogenous fibrolytic enzymes (EFE; a mixture of two preparations from Trichoderma spp., with predominant xylanase and β-glucanase activities, respectively) on colonization and digestion of ground barley straw and alfalfa hay by Fibrobacter succinogenes S85 and Ruminococcus flavefaciens FD1 were studied in vitro. The two levels (28 and 280 μg/ml) of EFE tested and both bacteria were effective at digesting NDF of hay and straw. With both substrates, more NDF hydrolysis (p<0.01) was achieved with EFE alone at 280 than at 28 μg/ml. A synergistic effect (p<0.01) of F. succinogenes S85 and EFE on straw digestion was observed at 28 but not 280 μg/ml of EFE. Strain R. flavefaciens FD1 digested more (p<0.01) hay and straw with higher EFE than with lower or no EFE, but the effect was additive rather than synergistic. Included in the incubation medium, EFE showed potential to improve fibre digestion by cellulolytic ruminal bacteria. In a second batch culture experiment using mixed rumen microbes, DM disappearance (DMD), gas production and incorporation of 15N into particle-associated microbial N (15N-PAMN) were higher (p<0.001) with ammoniated (5% w/w; AS) than with native (S) ground barley straw. Application of EFE to the straws increased (p<0.001) DMD and gas production at 4 and 12 h, but not at 48 h of the incubation. EFE applied onto S increased (p<0.01) 15N-PAMN at 4 h only, but EFE on AS increased (p<0.001) 15N-PAMN at all time points. Prehydrolysis increased (p<0.01) DMD from both S and AS at 4 and 12 h, but reduced (p<0.01) 15N-PAMN in the early stage (4 h) of the incubation, as compared to non-prehydrolyzed samples. Application of EFE to barley straw increased rumen bacterial colonization of the substrate, but excessive hydrolytic action of EFE prior to incubation decreased it.

Utilisation of Barley Straw by Steers: The Effect of Quantity and Source of Nitrogen on the Degradation of Straw Fractions, Particle Outflow Rate and Intake

Nsahlai, I.V., Bryant, M.J. and Umunna, N.N. 1998. Utilisation of barley straw by steers: The effect of quantity and source of nitrogen on the degradation of straw fractions, particle outflow rate and intake. J. Appl. Anim. Res., 14: 33–50. This study evaluated the effect of quantity of rumen degradable nitrogen (RDN; 1.37 vs 1.87 g RDN/MJ ME) and of source of nitrogen (N; Fish vs rapeseed meal) on the degradability of straw fractions, rumen metabolities, particle passage rate, intake and digestibility of barley straw using six ruminally fistulated Friesian steers in a replicated 3x3 latin square experimental design. The degradability of leaves of spring (LS) and unknown (LU)varieties and stems of spring (SS) and unknown (SU) varieties of barley straw was determined. The three test protein supplements were designated low nitrogen with rapeseed meal (LNR; 1.37 g RDN/MJ ME; 14.25 g N/kg DM) and high nitrogen with either rapeseed meal (HNR; 1.86 g RDN/MJ ME; 18.80 g N/kg DM) or fish meal (HNF; 1.36 g RDN/MJ ME; 18.82 g N/kg DM). For both the DM and ADF, leaves degraded to a greater extent (P<0.01) and faster (P<0.01) than stems. Increased RDN improved the rate of degradation of straw fraction by proportionately 0.082 to 0.289, but the difference was significant (P<0.05) for the LS fraction only. With the exception of LU, HNF increased (P<0.05) the rate of degradation by proportionately 0.139 to 0.153 compared with LNR. Both HNR and HNF increased straw intake relative to the LNR. HNR also increased the duration over which rumen concentration of ammonia-N was above 14 mg/l compared to HNF (P<0.05) and LNR (P<0.05). Meanwhile, HNF sustained higher ruminal concentrations of iso-valerate than either HNR or LNR. The HNR and HNF diets were respectively associated with 7% and 10% increase in the flow of indigestible matter through the gut. It was concluded that the quantity of RDN but not the source of N is an important factor affecting the degradation of leaves of barley straw.

Estimation of in vitro digestibility of barley straw by using a homogenized rumen fluid and artificial saliva mixed with nitrogen and energy sources

Estimation of in vitro digestibility of barley straw by using a homogenized rumen fluid and artificial saliva mixed with nitrogen and energy sources

Effects of chemical treatments of barley straw on leaching, and digestibility by rumen fluid and cellulolytic bacteria

Effects of chemical treatments on in sacco and in vitro digestibility of barley straw by rumen fluid and pure cultures of celluloytic bacteria were studied to evaluate the pretreatment and to improve the poor quality feed. Chemicals were applied by dissolving them in water equivalent to 40% of the weight of the straw (dry matter basis). Pretreatment with 5% NaOH yielded the largest increase in sacco digestion followed by pretreatment with 2% (NH4)2SO3, 2.6% NH4OH, 1.6% NaHSO3 and untreated straw (control). In sacco dry matter digestibility of straw treated with NaOH and (NH4)2SO3 continued to increase as the concentration of chemical increased (1 to 7.5%), as it was the in vitro dry matter loss by leaching. Treatment of barley straw with 5% NaOH enhanced significantly (p<0.01) in vitro digestibility by rumen fluid, Fibrobacter succinogenes and Ruminococcus albus though the fermentation products by celluloytic bacteria were low, whereas the treatment with 5% (NH4)2SO3 inhibited in vitro digestibility by F. succinogenes and R. albus together with lower fermentation products. Dry matter loss by leaching and bacterial digestion from barley straw treated with NaOH and (NH4)2SO3 suggested the effect of pretreatment with these chemicals were based on leaching, and the celluloytic bacteria had little to do with digestion.

Influence of variety, row type and time of sowing on the morphology, chemical composition and in vitro digestibility of barley straw

SUMMARYLeaf proportions (LP) were determined in spring barley straws harvested at Cambridge in 1984 and 1985. Linear regression equations showed that a greater number of days to flowering increased LP whilst greater plant height decreased LP in spring barley straws. Plant height accounted for more than 70% of the variance in LP. By contrast, grain yield and stem diameter accounted for only a small percentage of the variance in LP. Straws from two-rowed winter barleys had slightly higher LP than six-rowed winter barleys but LP in winter and spring barleys were similar.Leaf blade and leaf sheath fractions of the straws had lower acid detergent fibre and lignin contents and were more digestible than the stem fractions. Linear regression equations of straw digestibility in spring barleys on LP, grain yields, days to flowering and plant heights showed that LP accounted for a higher percentage of the variance in digestibility in 1984 than the other characteristics. In 1985, when harvesting conditions were unusually wet, grain yield accounted for the highest percentage of the variance in straw digestibility.There were no differences in chemical composition and straw digestibility between two-rowed and six-rowed barleys, but winter barleys had higher straw digestibility than spring barleys. Date of sowing did not influence straw quality in two-rowed winter barleys.The ranking of two-rowed spring barleys for LP, chemical composition and digestibility suggested that varieties with consistently better straw quality could be identified.

Use of a ‘Floor’ method instead of metabolism crates for collecting faeces from goats, for estimating digestibility of dry matter

Total collection of faeces from goats fed long straw ad libitum in crates requires much labour. This is particularly so when feeding straw generously to facilitate selection by goats of the more nutritious leaf-plus-sheath component (Wahed, Owen, Naate and Hosking, 1990). Confining goats in crates is also stressful to animals and in future will be discouraged. An experiment was therefore made to compare the digestibility of barley straw supplemented with concentrates, measured by collecting faeces in one of two ways. One involved total collection of faeces from goats confined in metabolism crates. The other involved estimating the output of faeces from the increase in weight of sawdust bedding provided for individually-penned goats.

Voluntary intake and digestibility of barley straw as influenced by variety and supplementation with either barley grain or cottonseed cake

Voluntary intake and digestibility trials using Awassi sheep were conducted with straw from seven barley varieties and a landrace from Syria. Two straws were allocated to each of four 4 × 4 Latin squares and one straw in each square was also supplemented with either barley grain (average 169 g per head day −1) or cottonseed cake (average 130 g per head day −1). Organic matter intakes (OMI) for the seven varieties ranged from 31.0 to 45.9 g kg −0.75 day −1 and were correlated ( P < 0.05) with straw yield ( r = 0.82) and days from sowing to maturity ( r = 0.78). Organic matter digestibility (OMD) ranged from 43.0 to 47.7% and was less important that voluntary intake in determining straw feeding value. For the landrace, straw OMI and OMD were 47.5 g kg −0.75 day −1 and 49.8%, respectively. Supplementation with barley grain improved straw OMI from 34.9 to 41.7 g kg −0.75 day −1 for a two-rowed variety ( P < 0.05) but did not significantly improve OMI of straw from three 6-rowed varieties. Cottonseed cake supplementation improved straw OMI for all four varieties tested ( P < 0.05) but OMI was significantly lower ( P < 0.05) for one six-rowed variety (43.5 g kg −0.75 day −1) compared with the three other varieties (55.6, 54.4 and 55.7 g kg −0.75 day −1). These results suggest the presence of variety × supplementation interactions for straw OMI. Within the barley/sheep farming system practiced in semi-arid areas of west Asia the selection of barley varieties with superior grain yield and straw quality could have an important impact on sheep production.

Effects of ammonia and sulphur dioxide gases on the composition and digestion of barley straw

Barley straw was prepared by hammermilling, or by cutting into pieces of internodal stem, and treated so as to contain 400 g water kg −1. The straw was used to examine the effects of NH 3 (0 or 95 g kg −1 DM) and SO 2 (none, or sufficient just to bleach the straw) in two replicated factorial experiments. NH 3 was applied for 28 days at 21 °C and SO 2 for 24 h at 21 °C. SO 2 was applied after the NH 3 in the combined treatment. Under these conditions, sulphuration alone had no effect on the amount or composition of the cell wall, no effect on any N fraction, and virtually no effect on digestibility. Ammoniation increased the total N content from 11.1 to 24.1 mg g −1 DM with the major part of the added N being NH 3-N. There were also increases in the cell wall N and the detergent-soluble, water-insoluble N. The cell wall organic matter was reduced from 754 to 662 mg g −1 DM owing to the solubilisation of some of the hemicellulose, with no effect on the cellulose. The combined treatment gave a further increase in total N (to 68.4 mg g −1 DM), again mainly through the retention of additional NH 3-N (69% of the added N). This treatment hydrolysed part of the cellulose, further reducing the cell wall organic matter to 520 mg g −1 DM. Although the cellulose content of ammoniated straw cell wall was greater than that of the untreated straw, the composition of the cell wall in untreated straw and in straw given the combined treatment, was similar. The total S contents were 4.5 and 49.4 mg g −1 DM after sulphuration and the combined treatment, respectively, compared with 1.5 mg g −1 DM in the untreated and ammoniated straws. Dry matter disappearances after nylon bag incubation for 48 h (an estimate of in vivo digestibility) and 120 h (an estimate of potential digestibility) were, respectively, 49, 65; 50, 66; 69, 82; 84, 94% for the nil, sulphuration, ammoniation and combined treatments. There were no treatment effects on the rate of DM digestion. The digestion of intact internodal stem tissues was slower than for the ground straw, and the potential (204 h) digestibility values were lower. However, the digestibility rankings were the same as for the ground straws.

A note on the effects of dietary protein degradability in the rumen on the voluntary intake and digestibility of barley straw by lactating beef cows

In a previous experiment with pregnant beef cows (Alawa, Fishwick, Parkins, Hemingway and Aitchison, 1986) when equal amounts of crude protein (CP) were supplied from a range of concentrates providing different amounts of rumen-degraded protein (RDP), the voluntary intake of barley straw dry matter (DM) and the metabolizable energy (ME) obtained from straw were positively and significantly correlated with the intake of RDP. Whilst increasing proportions of rumen-undegraded protein (UDP) have been shown to increase the milk yield of ewes (Robinson, McHattie, Calderon Cortes and Thompson, 1979) the response of lactating beef suckler cows to UDP in terms of milk yield is not clear. There is an increasing interest in the use of peas as a protein supplement but they have not been compared with more conventional protein sources. Accordingly these present experiments were conducted to study the response of lactating beef cows and their calves to proteins from different sources providing different amounts of RDP and UDP.

Treatment of barley straw with mixtures of calcium hydroxide and urea : Effect on intake and digestibility in sheep

Calcium hydroxide (Ca(OH)2) is widely available in Third World countries because of extensive limestone deposits. Previous studies (reviewed by Owen et al 1984) have shown Ca(OH)2-treated straw to be prone to mouldiness and low intakes. Urea was added to Ca(OH)2 in the present study to inhibit mould and supply nitrogen. Two experiments are reported which investigated the amounts of Ca(OH)2 and urea required for improving intake and digestibility of barley straw in sheep.Forty Suffolk x Mule store lambs (20 castrates, 20 ewe lambs) aged 8 months were used to measure intake and digestibility of 5 straws (Table 1) in a randomized block experiment, with blocking according to weight and sex. Animals were fed restricted concentrates (Table 1) and ad libitum straw (allowing refusals of 25% of intake) over a period of 35 days, with collection of faeces over the last 8 days. For treatment, straw was chopped, mixed with chemical solutions (Table 1) in a concrete mixer, and “ensiled” for 60 days (September &amp; October) at 500 g dry matter (DM) per kg, in plastic bags contained in 45-gallon oil drums. Straw was aerated for 3 days before feeding. Untreated straw was simply chopped before feeding.

Intake and Digestibility of Barley Straw by Goats : Effect of Ammonia Treatment of Straw and Straw-Previously-Refused by Goats

Wahed and Owen (1986) reported a 0.33 increase in barley straw dry matter (DM) intake when stall-fed goats were allowed to refuse 0.5 of the amount offered rather than the 0.2, or less, allowed in conventional ad lib feeding. This approach offers a possible strategy for maximising intake and improving utilization of straw in Third World countries developing stall feeding systems for goats based on crop residues and other by-products. Generous feeding of straw (say allowing refusal-rates of 0.5 of amounts offered) could be followed by the refeeding of refusals after treating them with ammonia.The experiment was undertaken to investigate refeeding straw previously refused by goats and to measure the effect of ammonia-treating such refusals on Intake and digestibility. Barley straw and refusals (0.5 of amount offered) of the same straw were chopped and half of each material treated with ammonia (0.11 of 330 g NH3/kg solution per kg straw in sealed plastic bags for 30 days).

Influence of energy source and dietary protein degradability on the voluntary intake and digestibility of barley straw by pregnant beef cows

ABSTRACTThree experiments, designed as three simultaneous 4 × 4 Latin squares (21-day feeding periods), were conducted using pregnant beef cows. Diets were based on barley straw given ad libitum together with 1·7 kg dry matter (DM) of either molassed sugar-beet pulp (MSBP) (experiment 1), unmolassed sugarbeet pulp (USBP) (experiment 2), or rolled barley (BARLEY) (experiment 3). In the respective experiments, MSBP, USBP and BARLEY were given either alone, to provide about 200 g crude protein (CP) per day (CONTROL) or were supplemented with urea (U), untreated soya-bean meal (SBM) or formaldehyde-treated soya-bean meal (FT-SBM) to provide a further 200 g CP per day. The contrasting dietary treatments in the three experiments provided intakes of rumen-degradable protein (RDP) ranging from 16 to 388 g/day.All protein supplements improved overall straw DM intakes, the improvement being significant for U only (P &lt; 0·01). A linear relationship between the daily intake of RDP (g) and straw DM (kg) was obtained. The regression equation was:DM intake = 5·03 + 0·0035 × RDP (R2 = 0·703; residual s.d. 0·561; d.f. 35; P &lt; 0·001).All protein supplements also improved the apparent digestibility of straw organic matter (OM) (P &lt; 0·05) and the metabolizable energy (ME) obtained from straw (P &lt; 0·01). Blood urea was increased due to supplementation with urea (P &lt; 0·001), SBM (P &lt; 0·01) and FT-SBM (P &lt; 0·05). Supplementation with BARLEY appeared to improve straw DM intake over MSBP and USBP but this was not reflected in improved ME intake from straw.

EFFECT OF BRANCHED-CHAIN AMINO ACIDS OR FATTY ACID SUPPLEMENTATION ON IN VITRO DIGESTIBILITY OF BARLEY STRAW OR ALFALFA HAY

In vitro dry matter digestibilities of ground barley straw or alfalfa hay, supplemented with branched-chain amino acids (valine, leucine and isoleucine) or their corresponding fatty acids (isobutyric, isovaleric and 2-methyl butyric acids), at 4% of substrate dry matter were determined. In vitro digestibilities were obtained after incubation in either rumen fluid or rumen fluid followed by pepsin in 0.1 N hydrochloric acid. Urea was added to the branched-chain fatty acid treatments so they were isonitrogenous with the amino acid treatments. Digestibility of barley straw was increased (P &lt; 0.05) by supplementation with all branched-chain fatty acids, when added either alone or in combination in both digestion systems. The greatest increase was from 34.8% for unsupplemented barley straw to 63.1% for barley straw plus all three branched-chain fatty acids. Valine did not improve digestibility of barley straw when incubated with either rumen fluid or rumen fluid followed by pepsin solution. Addition of isoleucine increased digestibility (P &lt; 0.05) of barley straw in both systems, while leucine was effective only when samples were incubated in both rumen fluid and pepsin solution. However, all combinations of amino acids increased (P &lt; 0.05) the digestibility of barley straw in both systems. In vitro digestibility of alfalfa hay was increased (P &lt; 0.05) only when valine and leucine were used together in either system. Incubating alfalfa hay in rumen fluid plus pepsin solution increased (P &lt; 0.05) in vitro digestibilites for all treatments. The greatest increase was from 72.8% for control to 89.5% for the treatment receiving a combination of valine and leucine. Key words: In vitro dry matter digestibility, branched-chain amino acids, branched-chain fatty acids, barley straw, alfalfa hay

Digestion and utilization of straw. 1. Effect of different chemical treatments on degradability and digestibility of barley straw by sheep

ABSTRACTBarley straw was treated with anhydrous ammonia, sodium hydroxide, ammonia plus sodium hydroxide, sulphuric acid or ammonia plus sulphuric acid to study the effect on the digestibility of straw and the degradability of the straw in the rumen of sheep.In experiment 1 four wethers fitted with rumen cannulae were given ammonia-treated straw to appetite and were used for measuring the dry- and organic-matter degradability of straw in the rumen after different in sacco incubation times. The organic-matter degradability (g/kg) after 48 h in sacco incubation was 459, 603, 576 and 660 for control, ammonia, sodium hydroxide and ammonia plus sodium hydroxide-treated straw respectively. Each treatment improved the degradability significantly (P &lt; 0·01). The effect of ammonia plus sodium hydroxide treatment on rumen degradability of straw was additive (P &lt; 0·05).In experiment 2 the treated straws studied in experiment 1 were given to four wethers in a 4 × 4 Latin-square design, to measure the voluntary intake, digestibility, water consumption and urine excretion. The digestibility (g/kg) and daily intake of digestible organic matter (g/kg M0·75 per day) were 554, 12·5; 628, 24·7; 653, 19·7; and 668, 24·3 for the control, ammonia, sodium hydroxide and ammonia plus sodium hydroxide-treated straws, respectively. Intake of ammonia-treated straw was significantly greater than for sodium hydroxide-treated straw (P &lt; 0·01). The water consumption and urine excretion by sheep were increased significantly by sodium hydroxide and ammonia plus sodium hydroxide treatments (P &lt; 0·01).In experiment 3, either straw or ammonia-treated straw were treated with 20, 40 and 60 g sulphuric acid (200 ml/1 solution per kg). The degradability of the acid-treated straws was measured using three wethers fitted with cannulae and given ammonia-treated straw to appetite. The dry-matter degradabilities (g/kg) after 48 h in sacco incubation were 52·0, 53·9, 58·7 and 67·4 for the control, and 20, 40 and 60 g acid per kg treatments, whereas the values were 61·3, 60·4, 68·4 and 69·4 for the ammonia-treated straw, and 20, 40 and 60 g acid per kg treatments respectively. There was a significant effect of acid treatment and ammonia treatment on dry-matter degradability.

Effect of chemical and physical treatment on the composition and digestibility of barley straw

Baled straw was used as a control material (1). Other straw materials were pressed into cobs. These included: straw pressed without additives (2); NaOH-treated pressed straw (3); pressed compound cobs with the ingredients 50% NaOH-treated straw, 40%grain (oats + barley) and 10% beet molasses (4); and straw pressed with 10% molasses (5). Diets 1,2,3 and 5 were supplemented with soy—barley mixture (1:1) 400 g/day peranimal and diet 4 with soy 100 g/day per animal. A Na-free mineral mixtures was included in all and NaCl was given with 1,2 and 5. A digestibility trial was carried out with castrated adult male sheep using a latin square design. The digestibility of organic matter was higher in control straw (47) than in pressed straw (40) or straw to which molasses was added (43). NaOH-treated pressed straw was digested better (57) than control straw. Compound straw—grain pellets had the highest digestibility (67).

The effect of a sodium hydroxide spray treatment on digestibility of barley straw in sheep and goats

To investigate the possible potential of cheaper foodstuffs for small ruminants, an experiment was designed to compare the digestibility and acceptability of barley straw and barley straw sprayed with sodium hydroxide (NaOH). In feeding trials involving six sheep and six goats, chopped untreated barley straw (US) was compared with straw chopped and sprayed with 5 g NaOH in 60 ml solution for each 100 g straw. The treated straw (TS) was neither washed nor neutralised. Both US and TS were fed to appetite to sheep and goats, with protein, mineral and vitamin supplements and water ad libitum. Both diets were readily consumed and there were no metabolic problems. Dry Matter Intake (g kg −1 W 0.75) was significantly increased (P < 0.05) in sheep but not in goats following alkali-treatment of the straw. The Energy Digestibility and Organic Matter Digestibility (OMD) of the TS diet were significantly higher than the US diet (P < 0.05) in both species. The digestibility of Crude Fibre (CF) by sheep and goats was markedly improved (P < 0.01) following treatment and the improvement was significantly higher (P < 0.05) for the sheep fed on US than for the goats fed US. Values for the OMD and Metabolisable Energy (ME) of the US and TS were derived and both parameters were significantly increased (P < 0.05) following treatment of the straw with alkali. TS, if adequately supplemented with nitrogen, minerals and vitamins is apparently capable of supplying the ME requirements for maintenance and limited production in sheep and goats.

Effect of Alkali Treatment on Intake and Digestion of Barley Straw by Beef Steers

Effect of Alkali Treatment on Intake and Digestion of Barley Straw by Beef Steers

Effect of aqueous ammonia and other alkalis on the in‐vitro digestibility of barley straw

AbstractThe in‐vitro digestibility of the organic matter of unground barley straw was increased by approximately 14 units by treatment with aqueous ammonia for 1 week at 20°C. Longer treatment times of 4 and 13 weeks had little or no additional effect on digestibility. Treatment with sodium hydroxide or tetramethylammonium hydroxide increased digestibility by up to 22 units. The content of cell walls of the straw after treatment with any of the alkalis was lower than that of untreated straw and the degradability of the walls from alkali‐treated straw was more than 85% greater than that of the walls from untreated straw. Alkali treatment of straw caused loss of p‐coumaric, ferulic and diferulic acids from the cell walls, the loss being greater with the stronger alkalis. The loss of ferulic was greater than that of p‐coumaric acid.

A note on the influence of a supplement of barley and dried lucerne on the intake of barley straw by cattle

SUMMARYSix castrated male cattle of 350 kg live weight were used in an incomplete Latin square design to measure intake and digestibility of barley straw offered ad libitum alone and with 5 levels, 1·5 to 7·5 kg/day, of a barley and dried lucerne concentrate. Straw intake declined and total organic-matter intake increased linearly with increasing concentrate level. On average 1 kg additional organic matter as concentrate, increased total organic-matter intake by 0·68 kg. There was no evidence that the crude protein content of the whole diet affected straw consumption.

Intake and digestion of barley straw by sheep given expelled groundnut meal with different amounts of calcium.

Six wether sheep were used in a 6×6 latin square experiment to study the effect of calcium intake on intake and digestibility of barley straw fedad libitum with low and high oil groundnut meal. The level of added calcium ranged from 1.6 to 3.0 g/day for the low oil and 6.4 to 10.4 g/day for the high oil diet. Each experimental period was of 21 days duration which comprised 14 days for adaption to the diet followed by a sevenday collection.