No abstract

This study was conducted in order to assess the influence of four doses (0, 0.5, 1, and 2 mg (g dry matter)-normal1 of commercial fibrolytic enzymes (MAXFIBER-Inormal®, SHAUMANN GmbH, Wahlstedt, Germany) on in vitro fermentation of date palm (Phoenix dactylifera) by-products: date kernels, wasted dates, floral stems, and palm fronds. Rumen contents were obtained from two non-lactating Holstein cows. Enzyme supplementation to by-products was carried out 12 h prior to incubation.Compared to the control, the enzymatic supplementation quadratically increased the extent but not the gas production rate of date kernel fermentation. Indeed, the potential gas production increased notably by 14.8 % with the lowest enzymes dose following recorded gas production after 48, 72, and 96 h of incubation. The estimated organic-matter digestibility, metabolisable energy, and total volatile fatty acids in the incubation fluid tended to be increased with the lowest dose by 7.8 %, 8.4 %, and 13.9 % respectively. For the wasted dates, this feed additive tended to linearly increase the gas production rate of fermentation with the highest dose. On the other hand, this supplementation had no effect on the ruminal fermentation of the floral stems and palm fronds. The exogenous fibrolytic enzymes were more effective on fibrous but not on lignified date palm by-products.

This research was performed to evaluate the effects of increasing doses of exogenous fibrolytic enzymes (EFE), namely at 0 (control), 1 (low), 2 (medium) and 4 (high) μL/g dry matter (DM), on the ruminal fermentation of low-quality agro-industrial by-products, grape pomace, almond hull and pomegranate peel. For pomegranate peel, the addition of EFE increased gas production linearly from the immediately soluble fraction, and from the insoluble fraction, the potential of gas production (significant linear effect), organic matter digestibility and metabolizable energy. The highest doses were the most effective. As the doses increased, the effectiveness increased accordingly. Unlike pomegranate peel, EFE had a quadratic effect on the indices of almond hull, namely a significant response on gas production from the immediately soluble fraction, the insoluble fraction, potential of gas production, organic matter digestibility and metabolizable energy. The lowest dose was the most effective while the highest dose had inhibitory effects for gas indices, organic matter digestibility and metabolizable energy. On the other hand, this supplementation had no effect on the ruminal fermentation of grape pomace. This study indicates that the response to this feed additive was influenced by the dose, the structure of the substrate, and the interaction between dose and the substrate. Exogenous fibrolytic enzymes could enhance the use of almond hull and pomegranate peel in ruminant nutrition, and reduce their negative environmental impact.

Abstract. Olive mill waste is low-quality feed and rarely used in ruminant nutrition because of its high lignocellulose content, the existence of anti-nutritional factors such as total polyphenol and condensed tannin, and low protein contents. This in vitro research was conducted to valorize this waste (crude olive cake, extracted olive cake, and olive leaves) using an exogenous fibrolytic enzyme produced from Trichoderma longibrachiatum in ruminal nutrition. The enzymatic activity of this additive was 1161 units of endoglucanase per millilitre, 113 units of exoglucanase per millilitre, and 2267 units of xylanases per millilitre. This treatment was applied by spraying substrates with four doses: 0 (control), 1 (low), 2 (medium), and 4µL g−1 µL g−1 (high) of dry matter olive mill waste in an air-conditioned room at 26 ∘C for 12 h before in vitro incubation. For the crude olive cake, this additive at high doses increased degradation of 14 % of cellulose and 8 % of hemicellulose compared with the control at 12 h before the in vitro incubation. Consequently, it increased dry matter solubility and reduced sugars at this period compared to the control. Upon ruminal incubation, the high dose of exogenous fibrolytic enzyme increased the gas production from the immediately soluble fraction and insoluble fraction, the rate of gas production for the insoluble fraction, the dry matter degradability by 26 %, the organic matter degradability by 24 %, the metabolizable energy value by 28 %, and the microbial crude protein production by 24 % compared with the control. For olive leaves, an exogenous fibrolytic enzyme at medium dosage can also hydrolyse the hemicellulose compound, release fewer sugars, and increase dry matter solubility compared with the control at 12 h before the in vitro incubation. Upon in vitro incubation, the medium dose increased the gas production from immediately soluble and insoluble fractions, the rate of gas production for the insoluble fraction, the dry matter degradability by 13 %, the organic matter degradability by 11 %, the metabolizable energy value by 12 %, and the microbial crude protein production by 12 % compared with the control. However, the highest dose altered the gas production from insoluble fractions and decreased microbial crude protein production by 6 % compared with the control. Under the same conditions, an exogenous fibrolytic enzyme applied to extracted olive cake did not produce any effect in the chemical composition and nutritional value. These results showed clearly that effectiveness of exogenous fibrolytic enzyme varied with incubated waste. Increasing the nutritional value of crude olive cake and olive leaves using an exogenous fibrolytic enzyme can encourage breeders to use this waste as feed at a low cost in animal nutrition. This valorization of waste is a good solution to reduce pollution of soils and groundwater caused by throwing out this polluted waste into the environment.

No abstract

The present study was undertaken to evaluate the efficacy of exogenous fibrolytics enzymes (EFE) to improve the in vitro cell wall hydrolysis, ruminal fermentation and digestibility of untreated (WS) and chemically pretreated wheat straw with NaOH (SWS), urea (UWS), and diluted H2SO4 (AWS). An in vitro gas production study during 96 h of incubation and an in vitro enzymatic hydrolysis during 20 h was conducted. The first EFE was a mixture (1:1, v/v) of cellulase and xylanase (Dyadic complex), applied at increasing doses (1, 2, 5 and 10 μl/g DM). The second EFE (MaxFiber complex) was also applied at increasing dose (0.5, 1, 2 and 4 mg/g DM). The rate and the extent of the in vitro gas production (GP) of WS improved with both EFE supplementation especially with the optimal doses D1 and M2. In association with NaOH pre-treatment, the EFE failed to have any effect on wheat straw digestibility. In contrast, the urea pre-treatment seems to have a synergetic effect with EFE on ruminal utilization by accelerating the fermentation process. However, for AWS an antagonist effect was detected with both EFE. Moreover, the in vitro enzymic hydrolysis indicated a linear positive effect of EFE on reducing sugar release for almost all substrates and an increase in dry matter losses for only WS and AWS. These results revealed that the positive effect of EFE supplementation effect depended on the type of chemical pre-treatments and it was detected only for WS and UWS.

This study aims to provide possible utilization of sunflower head byproduct (SFH) as a feedstuff by implementing chemical pretreatments (4% sodium hydroxide (SFHNaOH) or 4% urea (SFHurea) and supplementation with either exogenous fibrolytic enzymes (EFE) or functional feed additive (FFA). The experimental EFE was a complex (1:1, v/v) of two enzyme products with high activity of β-1,3-1,4-glucanase and endo-1,4-β-D-xylanase and applied at 0 (SFHout), 1, 2, 5, and 10 µL/ gdry matter, while FFA was a fermentation byproduct rich in cellulase and xylanase activities, applied at 0 (SFHout), 0.5, 1, 2, and 4 mg/g DM. SFHurea had the highest (p < 0.05) crude protein (CP) content compared to other SFH substrates. Linear enhancements (p < 0.05) in kinetics of gas production (GP), metabolizable energy (ME), organic matter digestibility (OMD) and total short-chain fatty acids (SCFAs) concentrations were observed for all SFH substrates supplemented with EFE. The SFHout had the highest (p < 0.05) potential GP, maximum rate (Rmax) of GP, ME, OMD and SCFAs. Supplementation of EFE was more pronounced than FFA in affecting the kinetic parameters of in vitro GP for all SFH substrates. SFHout supplemented with EFE seems to be the most promising substrate to enhance microbial fermentation in vitro.

No abstract