Vocal fold injection material does not preclude interpretation of laryngeal electromyography.

INTRODUCTION/AIMS: Temporary vocal fold injection (VFI) is a common treatment for acute and subacute vocal fold paralysis (VFP). Laryngeal electromyography (LEMG) is useful for diagnosing neurogenic causes of VFP. This study evaluated whether the presence of VFI material prevents interpretation of LEMG in patients with acute and subacute VFP. METHODS: Patients with acute and subacute unilateral VFP (onset ≤6 mo) who underwent temporary VFI within 3 mo preceding LEMG were evaluated. A matched control group that did not undergo VFI was also studied. The LEMG team (laryngologist and electromyographer) performed and interpreted LEMG using a pre-specified protocol, including qualitative and quantitative motor unit analysis. RESULTS: Eighteen patients with VFI underwent LEMG successfully with interpretation of spontaneous activity and motor unit recruitment. Fourteen patients were seen in follow-up to determine accuracy of established LEMG prognosis. Seven of seven subjects with poor LEMG prognosis did not recover vocal fold motion. Five of seven subjects with fair LEMG prognosis recovered vocal fold motion. Findings were similar for the control group. DISCUSSION: VFI augmentation material did not prevent interpretation of meaningful LEMG data in patients with acute and subacute VFP, and accurate prognoses of vocal fold motion recovery were established.

Effects of fibre-degrading enzymes in combination with different fibre sources on ileal and total tract nutrient digestibility and fermentation products in pigs.

The study was conducted to determine effects of a complex of fibre-degrading enzymes (xylanase, cellulase and ß-glucanase) on nutrient digestibility, fibre fermentation and concentrations of short chain fatty acids (SCFA) at different parts of digestive tract in pigs fed different fibre-rich ingredients. A total of 36 barrows fitted with T-cannulas in the distal ileum (initial body weight of 41.1 ± 2.7 kg) were randomly allotted to six dietary treatments with three different high-fibre diets including maize bran (MB), sugar beet pulp (SBP) and soybean hulls (SH) with or without supplementation of fibre-degrading enzymes. Enzyme supplementation improved (p < 0.05) apparent ileal digestibility (AID) of dietary gross energy (GE), crude protein, dry matter (DM), organic matter (OM), total dietary fibre (TDF), neutral detergent fibre (NDF) and apparent total tract digestibility (ATTD) of dietary GE, DM, OM, TDF, insoluble dietary fibre (IDF) when pigs were fed MB, SBP or SH diets. When compared to the SBP and SH diets, the AID of GE, DM, ash, OM and NDF in diet MB was higher (p < 0.05), but the hindgut disappearance and ATTD of nutrients, except for ether extract and crude ash, were lower (p < 0.05). Enzyme supplementation increased acetate and total SCFA concentrations in ileal digesta and faeces of pigs. In conclusion, enzyme addition improved IDF fermentation and SCFA concentration in the whole intestine of pigs, and there was a large variation of digestibility of fibre components among MB, SH and SBP owing to their different fibre composition. Therefore, fibre-degrading enzymes should be applied to fibrous diets to improve efficient production of swine, especially considering low fibre digestibility of fibre-rich ingredients.

Effect of cellulase and Lactobacillus casei on ensiling characteristics, chemical composition, antioxidant activity, and digestibility of mulberry leaf silage.

With the lack of feed resources in China, mulberry leaves have been developed as a ruminant forage rich in protein and functional components. To make full use of mulberry leaves, including their nutrients and biological activities, we investigated the effects of cellulase and Lactobacillus casei LC on the nutritive value and antioxidant capacity of mulberry leaf silage. Mulberry leaves from 2 locally prevailing high-yield cultivars were separately subjected to ensiling treatments either with or without addition of Lactobacillus culture, in combination with variable levels of cellulase application. After 60-d ensiling, the resulting silage was sampled and analyzed for fermentation parameters, antioxidant activity, carbohydrates, and protein fractions, as well as in vitro rumen gas production. The results showed that nutrients, including functional components of mulberry leaves, were well preserved during the ensiling process. Compared with the control, the application of cellulase and Lactobacillus casei LC resulted in greater dry matter recovery, higher contents of lactic acid, true protein, and total flavonoid, and increased antioxidant activity and microbial protein production, as well as decreased pH value, lower concentrations of ammonium nitrogen, and lower fiber fractions in the mulberry leaf silage, which varied between the 2 selected mulberry cultivars. These results suggest that mulberry leaf silage could be a quality feed with robust antioxidant capacity, which could be improved by the application of cellulase and Lactobacillus casei LC.

The impact of direct-fed microbials and enzymes on the health and performance of dairy cows with emphasis on colostrum quality and serum immunoglobulin concentrations in calves.

Thirty-six cows were blocked by calving date and randomly assigned to one of three treatments. Cows were on treatments 3 weeks prepartum through 8 weeks post-partum. Treatments were as follows: (i) no direct-fed microbial (DFM) or cellulase and amylase enzymes (C), (ii) 45.4 g/day of DFM (D) or (iii) 45.4 g/day of DFM and 18.2 g/day of enzyme (DE). Total mixed ration fed and refused were measured daily to determine dry matter intake (DMI). Blood samples were taken three times weekly and analysed for ß-hydroxybutyrate, glucose and non-esterified fatty acids. Body weight (BW) was measured weekly. Colostrum was weighed and analysed for IgA and IgG concentration. Calves were fed 4 L of colostrum within 2 hr of birth. Calf blood samples were taken at 0 and 24 hr for analysis of IgA and IgG concentrations and apparent efficiency of absorption. Milk yield was measured daily and samples collected weekly. Initial BW was different among treatments with D being lesser than C or DE treatments. Body weight, weight gain, efficiency of gain, DMI and blood parameters were unaffected. Treatment did not affect colostrum yield. Ash percentage of colostrum tended to increase with D and DE, while IgA and total solids yield decreased with D. Colostrum fat yield was decreased in D and DE. Treatments did not impact BW, serum IgA and IgG concentrations or apparent efficiency of absorption of calves. Post-partum BW, DMI, blood parameters, milk production and composition were unaffected by treatment. However, cows on D gained more BW and tended to have greater efficiency of gain compared to those on DE, but were similar to C. Somatic cell scores were greatest for D. Results indicate that DFM and enzyme supplementation did not improve health and performance of dairy cattle during the pre- and post-partum periods under conditions of this study.

A meta-analysis on the effect of dietary application of exogenous fibrolytic enzymes on the performance of dairy cows.

The aim of this study was to use meta-analytical methods to estimate effects of adding exogenous fibrolytic enzymes (EFE) to dairy cow diets on their performance and to determine which factors affect the response. Fifteen studies with 17 experiments and 36 observations met the study selection criteria for inclusion in the meta-analysis. The effects were compared by using random-effect models to examine the raw mean difference (RMD) and standardized mean difference between EFE and control treatments after both were weighted with the inverse of the study variances. Heterogeneity sources evaluated by meta-regression included experimental duration, EFE type and application rate, form (liquid or solid), and method (application to the forage, concentrate, or total mixed ration). Only the cellulase-xylanase (C-X) enzymes had a substantial number of observations (n = 13 studies). Application of EFE, overall, did not affect dry matter intake, feed efficiency but tended to increase total-tract dry matter digestibility and neutral detergent fiber digestibility (NDFD) by relatively small amounts (1.36 and 2.30%, respectively, or <0.31 standard deviation units). Application of EFE increased yields of milk (0.83 kg/d), 3.5% fat-corrected milk (0.55 kg/d), milk protein (0.03 kg/d), and milk lactose (0.05 kg/d) by moderate to small amounts (<0.30 standard deviation units). Low heterogeneity (I 2 statistic <25%) was present for yields and concentrations of milk fat and protein and lactose yield. Moderate heterogeneity (I 2 = 25 to 50%) was detected for dry matter intake, milk yield, 3.5% fat-corrected milk, and feed efficiency (kg of milk/kg of dry matter intake), whereas high heterogeneity (I 2 > 50%) was detected for total-tract dry matter digestibility and NDFD. Milk production responses were higher for the C-X enzymes (RMD = 1.04 kg/d; 95% confidence interval: 0.33 to 1.74), but were still only moderate, about 0.35 standardized mean difference. A 24% numerical increase in the RMD resulting from examining only C-X enzymes instead of all enzymes (RMD = 1.04 vs. 0.83 kg/d) suggests that had more studies met the inclusion criteria, the C-X enzymes would have statistically increased the milk response relative to that for all enzymes. Increasing the EFE application rate had no effect on performance measures. Application of EFE to the total mixed ration improved only milk protein concentration, and application to the forage or concentrate had no effect. Applying EFE tended to increase dry matter digestibility and NDFD and increased milk yield by relatively small amounts, reflecting the variable response among EFE types.

Improving the performance of dairy cattle with a xylanase-rich exogenous enzyme preparation.

The objective of this experiment was to examine effects of adding 2 exogenous fibrolytic enzymes (EFE) to the total mixed ration (TMR) on the performance of lactating dairy cows (experiment 1) and the kinetics of ruminal degradation of the diet (experiment 2). Twelve EFE had been screened in a series of in vitro assays that identified the most potent EFE and their optimal doses for increasing the digestibility of bermudagrass. In experiment 1, 66 Holstein cows (21±5 d in milk) were grouped by previous milk production and parity (45 multiparous and 21 primiparous) and assigned randomly to 1 of the following 3 treatments: (1) control (CON, untreated), (2) Xylanase Plus [2A, 1mL/kg of TMR dry matter (DM); Dyadic International, Jupiter, FL], and (3) a 75:25 (vol/vol) mixture of Cellulase Plus and Xylanase Plus EFE (3A, 3.4mL/kg of TMR DM; Dyadic International). The EFE were sprayed twice daily onto a TMR (10% bermudagrass silage, 35% corn silage, 5% alfalfa-orchardgrass hay mixture, and 50% concentrates; DM basis) and fed for a 14-d training and covariate period and a 70-d measurement period. Experiment 2 aimed to examine the in situ DM ruminal degradability and ruminal fermentation measurements of the diets fed in experiment 1. Three ruminally fistulated lactating Holstein cows were assigned to the diets. The experiment had a 3×3 Latin square design with 23-d periods. In experiment 1, application of 2A increased intakes (kg/d) of DM (23.5 vs. 22.6), organic matter (21.9 vs. 20.9), and crude protein (3.9 vs. 3.7) and tended to increase yields (kg/d) of fat-corrected milk (41.8 vs. 40.7) and milk fat (1.48 vs. 1.44). In particular, 2A increased milk yield (kg/d) during wk 3 (41.2 vs. 39.8, tendency), 6 (41.9 vs. 40.1), and 7 (42.1 vs. 40.4), whereas 3A increased milk yield (kg/d) during wk 6 (41.5 vs. 40.1, tendency), 8 (41.8 vs. 40.0), and 9 (40.9 vs. 39.5, tendency). In experiment 2, EFE treatment did not affect ruminal DM degradation kinetics or ruminal pH, ammonia-N, and volatile fatty acid concentration. Application of 2A to the bermudagrass-based TMR increased DM intake and milk production, implying that this EFE could be used to increase the performance of lactating dairy cows fed diets containing up to 10% bermudagrass.

Effects of cellulase supplementation to corn soybean meal-based diet on the performance of sows and their piglets.

A total of 15 primiparous sows (Landrace × Yorkshire) and their litters were used in the current study to evaluate the efficacy of cellulase supplementation on the production performance of sows and piglets. Pigs were randomly allocated into one of three treatments with five replicates per treatment. The dietary treatments were as follows: (i) CON (corn-soybean meal-based control); (ii) EZ1 (CON + 0.05% cellulase); and (iii) EZ2 (CON + 0.10% cellulase). The supplementation of cellulase had no effect (P > 0.05) on body weight and feed intake of lactating sows. At weaning, back fat thickness loss decreased (P = 0.04) linearly in EZ1 and EZ2 treatments. The average daily gain (ADG) of piglets increased (linear P = 0.06, quadratic P = 0.04)) during days 14 to 21 as well as at days 21 to 25 (linear P = 0.03 and quadratic P = 0.01) with the increase in the level of supplemented enzyme. Dry matter and nitrogen digestibility increased (linear P = 0.01) in lactating sows fed EZ1 and EZ2 diet compared with CON. In conclusion, it is suggested that cellulase supplementation to corn-soybean meal based diet exerts beneficial effects to sows in reducing their back fat thickness loss at weaning and also helps to improve nutrient digestibility. It also helped to improve the ADG of piglets.

Effect of wheat dried distillers grains with solubles and fibrolytic enzymes on ruminal fermentation, digestibility, growth performance, and feeding behavior of beef cattle.

Two experiments were conducted to evaluate the effect of wheat dried distillers grains with solubles (DDGS) and fibrolytic enzymes (FE) on ruminal fermentation, in situ ruminal and in vivo total tract digestibility, growth performance, and feeding behavior of growing beef cattle. In Exp. 1, 6 ruminally cannulated Angus heifers (average BW of 794 ± 44.2 kg) were used in a 6 × 6 Latin square design with 2 × 3 factorial arrangement of treatments. Treatments were a control diet consisting of 50% barley silage, 10% grass hay, and 40% barley grain-based concentrate (CON) and the CON with 15% DDGS substituted for barley grain (WDG) combined with either 0, 1, or 2 mL FE/kg diet DM, respectively. Inclusion of DDGS increased total tract digestibility of CP ( < 0.01), NDF ( = 0.04), and ADF ( = 0.03). Increasing FE linearly ( = 0.03) increased CP digestibility without affecting the digestibility of other nutrients. There were no effects of DDGS inclusion or FE on ruminal pH or VFA concentration except that propionate was greater ( = 0.04) with the WDG. In situ ruminal DM and NDF disappearance of barley silage was greater ( < 0.04) in heifers fed the WDG than in heifers fed the CON after 24 h of incubation. Increasing FE linearly ( = 0.03) increased in situ NDF disappearance of barley silage after 24 h of incubation. In Exp. 2, 120 weaned steers (initial BW of 289 ± 11.0 kg) were fed diets similar to those in Exp. 1. The steers fed the WDG had greater ( < 0.01) final BW, ADG, DMI, and G:F compared with steers fed the CON. Increasing FE did not alter ADG or G:F but tended ( < 0.07) to linearly decrease DMI. There were interactions ( < 0.02) between DDGS and FE on eating rate and the time spent at the feed bunk. Supplementing FE decreased ( < 0.01) time at the bunk and increased ( < 0.01) eating rate for steers fed the WDG but not for steers fed the CON. Eating rate ( < 0.01) and meal frequency ( = 0.02) were greater but eating duration was shorter ( < 0.01) for steers fed the WDG than for those fed the CON. These results indicate that inclusion of wheat DDGS in a growing diet increased total tract digestibility of NDF and CP and improved the feed efficiency of steers. Moreover, supplementation of FE in barley silage-based growing diets may also have the potential to increase profits, with the evidence of the trend for a decline on DMI without decreasing ADG when adding FE.

In vitro and in vivo evaluation of biodegradable embolic microspheres with tunable anticancer drug release.

Natural polymer-derived materials have attracted increasing interest in the biomedical field. Polysaccharides have obvious advantages over other polymers employed for biomedical applications due to their exceptional biocompatibility and biodegradability. None of the spherical embolic agents used clinically is biodegradable. In the current study, microspheres prepared from chitosan and carboxymethyl cellulose (CMC) were investigated as a biodegradable embolic agent for arterial embolization applications. Aside from the enzymatic degradability of chitosan units, the cross-linking bonds in the matrix, Schiff bases, are susceptible to hydrolytic cleavage in aqueous conditions, which would overcome the possible shortage of enzymes inside the arteries. The size distribution, morphology, water retention capacity and degradability of the microspheres were found to be affected by the modification degree of CMC. An anticancer drug, doxorubicin, was successfully incorporated into these microspheres for local release and thus for killing cancerous cells. These microspheres demonstrated controllable degradation time, variable swelling and tunable drug release profiles. Co-culture with human umbilical vein endothelial cells revealed non-cytotoxic nature of these microspheres compared to monolayer control (P>0.95). In addition, a preliminary study on the in vivo degradation of the microspheres (100-300µm) was performed in a rabbit renal embolization model, which demonstrated that the microspheres were compatible with microcatheters for delivery, capable of occluding the arteries, and biodegradable inside arteries. These microspheres with biodegradability would be promising for embolization therapies.

The thermostable ß-1,3-1,4-glucanase from Clostridium thermocellum improves the nutritive value of highly viscous barley-based diets for broilers.

1. Microbial ß-1,3-1,4-glucanases improve the nutritive value of barley-based diets for poultry by effectively decreasing the degree of polymerisation of the anti-nutritive soluble ß-glucans. Glycoside hydrolases (GHs) acting on recalcitrant polysaccharides display a modular architecture comprising a catalytic domain linked to one or more non-catalytic Carbohydrate-Binding Modules (CBMs). 2. GHs and CBMs have been classified in different families based on primary structure similarity (see CAZy webpage at http://www.cazy.org ). The role of CBMs is to anchor the appended GHs into their target substrates, therefore eliciting the efficient hydrolysis of structural carbohydrates. 3. Here we describe the biochemical properties of the family 16 GH from Clostridium thermocellum, termed CtGlc16A. CtGlc16A is a thermostable enzyme that specifically acts on ß-1,3-1,4-glucans with a remarkable catalytic activity (38000 U/mg protein). 4. CtGlc16A, individually or fused to the family 11 ß-glucan-binding domain of cellulase CtLic26A-Cel5E of C. thermocellum, was used to supplement a highly viscous barley-based diet for broilers. 5. The data showed that birds fed on diets supplemented with the recombinant enzymes displayed an improved performance when compared with birds given diets not supplemented with exogenous enzymes. However, inclusion of the non-catalytic CBMs had no influence on the capacity of CtGlc16A to reduce the anti-nutritive effects of soluble ß-1,3-1,4-glucans. 6. The data suggest that at elevated dosage rates, CBMs might be unable to potentiate the catalytic activity of appended catalytic domains; this effect may only be revealed when feed enzymes are incorporated at low levels.

Safety and efficacy of carboxymethylcellulose in the treatment of glottic insufficiency.

OBJECTIVES/HYPOTHESIS: No studies to date have examined the clinical safety and efficacy of carboxymethylcellulose (CMC) for vocal fold injection. The current study investigates the voice outcomes and complications of CMC injection. STUDY DESIGN: Retrospective review. METHODS: All patients who underwent CMC injection from three independent sites in a 1-year period were reviewed. Voice outcomes in the form of voice handicap index-10 (VHI-10) and complications from injection were recorded. RESULTS: Seventy-eight patients with VHI-10 results from 1 to 8 weeks after CMC injection were evaluated. Thirty-eight patients were treated for vocal fold immobility, and 15 patients underwent treatment for hypomobility, 15 for vocal fold atrophy, seven for scar/sulcus, one for previous laryngeal fracture, one for functional dysphonia, and one for persistent granuloma. In 60 patients with available VHI-10 data, overall improvement in voice was seen. There was a mean decrease in VHI-10 of 7.48 (26.4 to 18.9, P < .05), correlating to a 19.9% decrease. Forty-five patients (75%) showed a decrease in VHI-10, nine (15%) showed an increase, and six (10%) showed no change. Statistically significant differences were seen for patients with immobility (decrease of 8.6, or 31%) and hypomobility (decrease of 10.7, or 37.8%). There were no complications of vocal fold stiffness, inflammatory reaction, or scar in the 78 patients during the total follow-up period. CONCLUSIONS: CMC is a viable, safe, and efficacious material for the temporary treatment of glottic insufficiency in vocal fold immobility and hypomobility, with minimal risk of permanent adverse voice outcomes.

Effects of a mono-component endo-xylanase supplementation on the nutritive value of wheat-based broiler diets.

1. Two trials were conducted to evaluate the effects of a mono-component thermostable endo-1,4-ß-xylanase derived from Thermomyces lanuginosus on the nutritive value of wheat-based broiler diets. In a 5-week growth trial, the efficacy of xylanase supplementation at 0, 100, 150, 200, 400 and 4000 FXU/kg diet was evaluated. A short-term balance trial was carried out according to a 4 × 2 factorial arrangement of treatments, involving 4 wheat cultivars and endo-xylanase at 0 or 200 FXU/kg. 2. In the growth trial, enzyme supplementation from 0 to 400 FXU/kg reduced feed intake and improved feed conversion linearly. Digesta viscosity was significantly reduced by all enzyme inclusion levels by 49·6-56·9%, in a quadratic manner. 3. In the balance trial, xylanase supplementation resulted in a significant improvement of protein, lipid and dry matter apparent digestibility coefficients of diets, accompanied by improved dietary AME(N) values. There was a significant wheat × enzyme interaction on AME(N) and lipid digestibility. There was a significant effect of wheat cultivar on dry matter digestibility.

Statistical optimization of single-cell production from Taxus cuspidata plant cell aggregates.

Flow-cytometric characterization of plant cell culture growth and metabolism at the single-cell level is a method superior to traditional culture average measurements for collecting population information. Investigation of culture heterogeneity and production variability by obtaining information about different culture subpopulations is crucial for optimizing bio-processes for enhanced productivity. Obtaining high yields of intact and viable single cells from aggregated plant cell cultures is an enabling criterion for their analysis and isolation using high-throughput flow cytometric methods. The critical parameters affecting the enzymatic isolation of single cells from aggregated Taxus cuspidata plant cell suspensions were optimized using response-surface methodology and factorial central composite design. Using a design of experiments approach, the output response single-cell yield (SCY, percentage of cell clusters containing only a single cell) was optimized. Optimal conditions were defined for the independent parameters cellulase concentration, pectolyase Y-23 concentration, and centrifugation speed to be 0.045% (w/v), 0.7% (w/v), and 1200 × g, respectively. At these optimal conditions, the model predicted a maximum SCY of 48%. The experimental data exhibited a 72% increase over previously attained values and additionally validated the model predictions. More than 99% of the isolated cells were viable and suitable for rapid analysis through flow cytometry, thus enabling the collection of population information from cells that accurately represent aggregated suspensions. These isolated cells can be further studied to gain insight into both growth and secondary metabolite production, which can be used for bio-process optimization.

Effect of feeding alfalfa hay or Tifton 85 bermudagrass haylage with or without a cellulase enzyme on performance of Holstein cows.

Forty-four lactating Holstein cows (173±30 DIM, 42.5±6.8 kg of milk, 4.03±0.69% fat, 674±78 kg of body weight) were used in an 8-wk, completely randomized trial with a 2 × 2 factorial arrangement of treatments to determine the effect of forage source and supplemental cellulase enzyme on performance. Treatments included 2 forage combinations (corn silage plus 12.2% dry matter, DM, from either alfalfa hay or Tifton 85 bermudagrass haylage) with or without a commercial cellulase enzyme applied to the total mixed ration at the rate of 4 g/head per day (Promote N.E.T.-L, Cargill Animal Nutrition, Minneapolis, MN). Experimental diets were formulated to provide similar concentrations of protein (16.5% of DM), energy (1.63 Mcal of net energy for lactation/kg of DM), and neutral detergent fiber (41.7% of DM) and were fed once daily as a total mixed ration behind Calan doors for ad libitum intake. The cellulase enzyme provided 1,200 cellulase units of activity/g of product and was applied to the total mixed ration and allowed to mix for 5min before feeding. Before beginning the trial, all cows were trained to use Calan (American Calan, Northwood, NH) doors and then fed the alfalfa hay-based diet for 2 wk. Data collected during wk 2 were used as a covariate in the statistical analysis. At the beginning of the 6-wk experimental period, cows were assigned randomly to 1 of the 4 experimental diets. No interactions were observed between forage and enzyme for any measures. Daily DM intake; milk yield; concentrations of milk fat, true protein, lactose, and solids not fat; energy-corrected milk yield; and dairy efficiency were not different among alfalfa or Tifton 85 bermudagrass rations with or without cellulase enzyme supplementation. The results of this trial indicate that Tifton 85 bermudagrass haylage can replace alfalfa hay in diets fed to high-producing, lactating dairy cows without depressing DM intake or milk yield when rations are balanced for NDF. Although supplemental cellulase enzymes have been shown to improve ration digestibility and animal performance in previous trials, no advantages were observed in the current trial.

Effect of different cellulase dosages on cell viability and ethanol production by Kluyveromyces marxianus in SSF processes.

This study was aimed to study the effect of commercial cellulases (Celluclast 1.5 LFG) on Kluyveromyces marxianus CECT 10875 growth and ethanol production in SSF processes. Preliminary tests carried out in glucose (50 g/L) fermentation medium showed that high enzyme amounts (2.5-3.5 FPU/mL) could cause a negative effect on K. marxianus growth rate and viable cells number. However, the maximum ethanol production was not affected and about 86% of the theoretical (22 g/L) was reached in all cases independently of the enzyme dosage. In SSF experiments, cell viability was always affected by enzyme loading. Nevertheless, slight differences observed on cell viability during glucose fermentation processes with the detected concentrations of the additives did not justify the negative effect observed in SSF experiments.

A family 11 carbohydrate-binding module (CBM) improves the efficacy of a recombinant cellulase used to supplement barley-based diets for broilers at lower dosage rates.

1. Exogenous microbial beta-1,3-1,4-glucanases and hemicellulases contribute to improving the nutritive value of cereals rich in soluble non-starch polysaccharides for poultry. 2. In general, plant cell wall hydrolases display a modular structure comprising a catalytic module linked to one or more non-catalytic carbohydrate-binding modules (CBMs). Based on primary structure similarity, CBMs have been classified in 50 different families. CBMs anchor cellulases and hemicellulases into their target substrates, therefore eliciting efficient hydrolysis of recalcitrant polysaccharides. 3. A study was undertaken to investigate the effects of a family 11 beta-glucan-binding domain in the function of recombinant derivatives of cellulase CtLic26A-Cel5E of Clostridium thermocellum that were used to supplement a barley-based diet at lower dosage rates. 4. The results showed that birds fed on diets supplemented with the recombinant CtLic26A-Cel5E modular derivative containing the family 11 CBM or the commercial enzyme mixture Rovabio Excel AP tended to display improved performance when compared to birds fed diets not supplemented with exogenous enzymes. 5. It is suggested that at lower than previously reported enzyme dosage (10 U/kg vs 30 U/kg of basal diet), the beta-glucan-binding domain also elicits the function of the recombinant CtLic26A-Cel5E derivatives. 6. Finally, the data suggest that exogenous enzymes added to barley-based diets act primarily in the proximal section of the gastrointestinal tract.

Influence of direct-fed fibrolytic enzymes on diet digestibility and ruminal activity in sheep fed a grass hay-based diet.

Six rumen-fistulated Merino sheep were used in a crossover design experiment to evaluate the effects of an exogenous fibrolytic enzyme preparation (12 g/d; ENZ), delivered directly into the rumen, on diet digestibility, ruminal fermentation, and microbial protein synthesis. The enzyme contained endoglucanase and xylanase activities. Sheep were fed a mixed grass hay:concentrate (70:30; DM basis) diet at a daily rate of 46.1 g/kg of BW(0.75). Samples of grass hay were incubated in situ in the rumen of each sheep to measure DM and NDF degradation. The supplementation with ENZ did not affect diet digestibility (P = 0.30 to 0.66), urinary excretion of purine derivatives (P = 0.34), ruminal pH (P = 0.46), or concentrations of NH(3)-N (P = 0.69) and total VFA (P = 0.97). In contrast, molar proportion of propionate were greater (P = 0.001) and acetate:propionate ratio was lower (P < 0.001) in ENZ-supplemented sheep. In addition, ENZ supplementation tended to increase (P = 0.06) numbers of cellulolytic bacteria at 4 h after feeding. Both the ruminally insoluble potentially degradable fraction of grass hay DM and its fractional rate of degradation were increased (P = 0.002 and 0.05, respectively) by ENZ treatment. Supplementation with ENZ also increased (P = 0.01 to 0.02) effective and potential degradability of grass hay DM and NDF. Ruminal fluid endoglucanase and xylanase activities were greater (P < 0.001 and 0.03, respectively) in ENZ-supplemented sheep than in control animals. It was found that ENZ supplementation did not affect either exoglucanase (P = 0.12) or amylase (P = 0.83) activity. The results indicate that supplementing ENZ directly into the rumen increased the fibrolytic activity and stimulated the growth of cellulolytic bacteria without a prefeeding feed-enzyme interaction.

An effective combination of carbohydrases that enables reduction of dietary protein in broilers: importance of hemicellulase.

After observing the effects of purified cellulase (C), hemicellulase (H), pectinase (P), and their combinations on the in vitro digestibility of a corn-soybean meal broiler diet, we examined the associations between pectin breakdown and the digestibilities of CP and DM by using free galacturonic acid (GA) as an index of pectin breakdown. There was no significant effect of the single enzymes except for H. However, the enzyme combinations H + P, C + H, and C + H + P significantly increased CP and DM digestibilities, whereas the combination of C + P was not effective. Because H has activities of both H and P, these enzymes were considered to be important in stimulating digestion. Furthermore, when the enzymes increased CP and DM digestibilities, GA concentration was significantly higher, and clear correlations between CP and DM digestibilities and GA concentration were observed, whereas correlations between the digestibilities and concentration of glucose or xylose + mannose as indices of cellulose and hemicellulose breakdown, respectively, were not significant. From these observations, we hypothesized that a mixture of enzymes could increase the protein digestibility of broiler feed. Thus, in the in vivo experiment, low-protein (19% CP) diets made mainly of corn and soybean meal with or without mixed enzymes were prepared and given to broiler chicks. The birds given the diet containing mixed enzymes showed significantly higher BW gain, with higher CP and DM digestibilities than the birds given the diet without the mixed enzymes. Moreover, the growth rate was same as that of the birds given the normal (21% CP) diet. The results indicate that the mixed enzyme preparation can effectively degrade indigestible cell constituents and thus enable the protein of the broiler feed to become more digestible. Furthermore, the results indicate the importance of H as a rate-limiting factor of cell wall breakdown.

Effects of yeast culture and fibrolytic enzyme supplementation on in vitro fermentation characteristics of low-quality cereal straws.

The effects of yeast culture and fibrolytic enzyme preparation (containing cellulase and xylanase) on in vitro fermentation characteristics of rice straw, wheat straw, maize stover, and maize stover silage were examined using an in vitro gas production technique. Four levels of yeast culture and fibrolytic enzyme supplements (0, 2.5, 5.0, and 7.5 g/kg of straw DM, respectively) were tested in a 4 x 4 factorial arrangement. Supplementation of yeast culture increased the cumulative gas production, theoretical maximum of gas production, rate of gas production, IVDMD, and in vitro OM disappearance (IVOMD), and decreased the lag time for each type of straw. Fibrolytic enzyme supplementation tended to increase cumulative gas production, theoretical maximum of gas production, and rate of gas production; prolonged lag time of gas production; and enhanced IVDMD and IVOMD for 4 types of cereal straws, with the significance of this effect being dependent on the level of supplemented enzymes. There were significant interactions between fibrolytic enzymes and yeast on all in vitro gas production parameters, IVDMD, and IVOMD of each type of straw. The outcome of this research indicated that the application of fibrolytic enzyme preparation and yeast culture could improve in vitro gas production fermentation of cereal straws.