Effect of forage type, harvesting time and exogenous enzyme application on degradation characteristics measured using in vitro technique

Effect of lactic acid bacteria, yeast, and their mixture on the chemical composition, fermentation quality, and bacterial community of cellulase-treated Pennisetum sinese silage

The present study investigated the effects of Lentilactobacillus buchneri, Saccharomyces cerevisiae, and a mixture of the two on the cellulose degradation and microbial community of cellulase-treated Pennisetum sinese (CTPS) during biological pretreatment. The CTPS was stored without additives (CK) or with L. buchneri (L), yeast (Y, S. cerevisiae), and their mixture (LY) under anaerobic conditions for 60 days. All inoculants enhanced the anaerobic fermentation of CTPS. In relative to L, inoculations with Y and LY decreased the cellulose level of fermented-CTPS by 8.90 ~ 17.13%. Inoculation with L inhibited the growth of Weissella cibaria during anaerobic storage. However, inoculations with LY increased the relative abundance of the homofermentative bacterium Lactiplantibacillus plantarum by 6.04%. Therefore, inoculating S. cerevisiae reduced the adverse effects of L. buchneri-stimulated fermentation on cellulose degradation by altering the bacterial community during anaerobic storage of P. sinese. This work provides a new insight for the subsequent anaerobic digestion of P. sinese.

Effects of Addition of Exogenous Fibrolytic Enzymes on Digestibility and Milk and Meat Production – A Systematic Review

Exogenous fibrolytic enzymes (EFE) added to the ruminant diet can increase fiber digestibility and production efficiency. A systematic review was conducted to understand the interactions between EFE and diet on digestibility and animal performance. The database included variables from 384 experiments with EFE and 264 controls from 85 papers published since 2000 (classification criteria: 1) type of study (in vitro, in situ, in vivo), 2) type of ruminants (sheep, buffaloes, goats, beef and dairy cattle), 3) primary EFE activity (cellulases (Cel) or xylanases (Xyl)), 4) forage proportion (FP), 5) type of plant (TP: legumes or grasses), 6) number of ingredients in diets, and 7) application time (AT)). In over 52.85% of cases, EFE improved the degradability of dry matter (DMD), neutral and acid detergent fiber (NDFD and ADFD), in vitro gas production (GP), volatile fatty acids (VFA), the acetate: propionate ratio (A:P ratio), protein and fat milk, milk yield and average daily gain (ADG) (by 7.78–21.85%). Cel improved organic matter degradability (OMD), GP, VFA, milk yield, and milk protein and fat content. EFE in FP≥40% diets enhanced the ADG, and in grassbased diets increased the dry matter intake (DMI). The AT of EFE affected the DMD, NDFD, and ADFD. Significant correlations were found between the improvements of NDFD or ADFD with DMD (r>0.59), milk yield (r=0.64), and ADG (r=0.59). In conclusion, many factors interact with EFE supplementation effects, but EFE consistently enhanced the DMD, NDFD, and ADFD of ruminant diets, which are related to improvements in productive performance.

Silage fermentation and ruminal degradation of cassava foliage prepared with microbial additive

To effectively utilize the tropical cassava (Manihot esculenta Crantz) foliage (CF) resources, the CF silages were prepared with microbial additives, including Chikuso-1 (CH1, Lactobacillus plantarum), Snow Lact L (SN, L. rhamnosus), Acremonium cellulase (CE), SN + CE and CH1 + CE. Silage fermentation, chemical composition and ruminal degradation were studied in Hainan, China. CF silages prepared with lactic acid bacteria (LAB) and CE were well preserved, with a higher (P < 0.05) lactic acid, a lower (P < 0.05) pH value, butyric acid content and NH3-N ⁄ total-N compared with the controls. The additive-treated silages showed increased crude protein (CP) content, but decreased (P < 0.05) NDF and ADF contents. Meanwhile, the additive treatment improved relative feed value and ruminal degradability of dry matter (DM), CP, neutral detergent fiber and acid detergent fiber. In addition, the combination of LAB and CE resulted in better fermentation quality and ruminal degradability compared with LAB or CE single treatment. The results demonstrated that the CF could be prepared as ruminant feed, and the combination of LAB and CE might exert beneficial synergistic effect on silage fermentation.

Comparative analysis of silage fermentation and in vitro digestibility of tropical grass prepared with Acremonium and Tricoderma species producing cellulases

Objective

To find out ways of improving fermentation quality of silage, the comparative analysis of fermentation characteristics and in vitro digestibility of tropical grasses silage applied with cellulases produced from Acremonium or Tricoderma species were studied in Thailand.

Methods

Fresh and wilted Guinea grass and Napier grass silages were prepared with cellulases from Acremonium (AC) or Trichoderma (TC) at 0.0025%, 0.005%, and 0.01% on a fresh matter (FM), and their fermentation quality, chemical composition and in vitro digestibility were analyzed.

Results

All silages of fresh Napier grass were good quality with lower pH, butyric acid, and ammonia nitrogen, but higher lactic acid content than wilted Napier grass and Guinea grass silage. Silages treated with AC 0.01% had the best result in terms of fermentation quality. They also had higher in vitro dry matter digestibility and in vitro organic matter digestibility at 6 and 48 h after incubation than other silages. Silages treated with lower levels at 0.005% or 0.0025% of AC and all levels of TC did not improve silage fermentation.

Conclusion

The AC could improve silage fermentation and in vitro degradation of Guinea grass and Napier grass silages, and the suitable addition ration is 0.01% (73.5 U) of FM for tropical silage preparation.

Silage fermentation and ruminal degradation of stylo prepared with lactic acid bacteria and cellulase

In order to improve the silage fermentation of stylo (Stylosanthes guianensis) in tropical areas, stylo silages were prepared with commercial additives Lactobacillus plantarum Chikuso-1 (CH1), L. rhamnasus Snow Lact L (SN), Acremonium cellulase (CE) and their combination as SN+CE or CH1 + CE, and the fermentation quality, chemical composition and ruminal degradation of these silages were studied. Stylo silages treated with lactic acid bacteria (LAB) or cellulase, the pH value and NH₃ -N ⁄ total-N were significantly (P < 0.05) decreased while the ruminal degradability of dry matter (DM), crude protein (CP), neutral detergent fiber (aNDFom) and acid detergent fiber (ADFom) were significantly (P < 0.05) increased compared to control. Compared to LAB or cellulase-treated silages, the DM, CP contents and relative feed value (RFV), and the ruminal degradability in LAB plus cellulase-treated silages were significantly (P < 0.05) higher, but the aNDFom content was significantly (P < 0.05) lower. CH1 + CE treatment was more effective in silage fermentation and ruminal degradation than SN+CE treatment. The results confirmed that LAB or LAB plus cellulase treatment could improve the fermentation quality, chemical composition and ruminal degradation of stylo silage. Moreover, the combined treatment with LAB and cellulase may have beneficial synergistic effects on ruminal degradation.

In vitro gas production of foliage from three browse tree species treated with different dose levels of exogenous fibrolytic enzymes

The aim of this study was to evaluate the effect of different dose levels of exogenous fibrolytic enzymes (EFE) on in vitro ruminal fermentation kinetics and energy utilization of foliages from three browse trees (Pithecellobium dulce, Heliocarpus velutinus and Guazuma ulmifolia). Mixture of EFE product was added to the leaves of the three browse tree species at three dose levels: 0 (control), 3.5 and 7.0 mg/g of DM. Chemical composition of the foliages, including plant secondary metabolites such as total phenolics (TP), saponins (SAP) and aqueous fraction (AF), was determined. In addition, in vitro assaying of ruminal gas production kinetics was determined for the three browse three foliages treated with EFE. P. dulce had the highest crude protein content (p < 0.05), whereas G. ulmifolia had the highest content of neutral detergent fibre and SAP (p < 0.05) and H. velutinus had the lowest content of TP (p < 0.05). The interaction between tree species and dose level of EFE was significant (p < 0.05) for gas production (GP) at 24 h of incubation, parameters b and c of the accumulated GP curve, short-chain fatty acids (SCFA) and metabolizable energy (ME). The lowest (p < 0.01) extent of accumulated GP as well as the b and c values occurred in G. ulmifolia at 0 mg EFE/g DM. P. dulce had the highest (p < 0.05) values for ME and SCFA at the highest dose of EFE. Tree species and dose level had significant (p < 0.05) effects on all parameters describing in vitro ruminal fermentation kinetics and energy utilization. Addition of EFE improved the fermentation kinetics of the browse species considered in this study.