Influence of maize genotypes and harvest stages on in-silo fermentation quality and nutritional value of corn silage during hot summer condition of the tropics

The aim of the experiment was to evaluate the potential of promising summer maize genotypes and optimal stage of harvesting these genotypes for ensiling in terms of dry matter (DM), starch, and crude protein (CP) yields, silage fermentation quality, nutrients profile, total digestible nutrients, metabolizable energy (ME) content, Cornell Net Carbohydrate and Protein System (CNCPS) carbohydrate (CHO) subfractions composition, in vitro DM digestibility (DMD) and in situ starch degradation characteristics. Six maize genotypes were chosen for the study: DK9108 from Monsanto, P30Y87, P3939 from Pioneer, QPM-300 (quality protein maize) and W94 from the International Maize and Wheat Improvement Center (CIMMYT), and a local cultivar, Afgoii, from the Cereal Research Institute (Persabaq, KP). A total of 72 plots (8 m × 10 m) were blocked in three replicate fields, and within each field, each genotype was sown in four replicate plots according to a randomized complete block design. For the data analysis, the Proc-Mixed procedure of Statistical Analysis System with repeated measure analysis of variance was used. The DM yield was strongly influenced (P < 0.001) by maize genotypes, varying from 12.6 to 17.0 tons/ha. Except for total CHO and ammonia nitrogen (NH3-N), the contents of all measured chemical components varied (P < 0.001) among the genotypes. Further comparison revealed that, genotype P3939 had a higher (P < 0.05) content of CP (7.27 vs. 6.92%), starch (36.7 vs. 27.9%), DMD (65.4 vs. 60.0%), ME (2.51 vs. 2.30 Mcal/kg) and lactic acid (5.32 vs. 4.83%) and lowest content of NDF (37.3 vs. 43.1%), pH (3.7 vs. 4.10) compared to the local cultivar (Afgoii). Advancement of post-flowering maturity from 25 to 35% DM (23 to 41 days after flowering (DAF)) increased (P < 0.05) the DM yield (10.4 to 17.8 tons/ha), starch content (29.1 to 35.0%), DMD (65.3 to 67.3%) and ME (2.34 to 2.47 Mcal/kg), and decreased (P < 0.001) the contents of CP (7.42-6.73%), NDF (48.8-38.5%), pH (4.10 to 3.60), NH3-N (8.93-7.80%N) and effective degradability of starch (95.4 to 89.4). Results showed that for higher yields and silage nutritional and fermentation quality, maize crops should be harvested at whole crop DM content of 30-35% (34 to 41 DAF). It was further concluded that genotype P3939 is the most suitable summer maize genotype for silage production in terms of yields and silage nutritional and fermentation quality under the hot environmental conditions of the tropics.

Novel techniques for the mass production of nutritionally improved, fungus-treated lignocellulosic biomass for ruminant nutrition

BACKGROUND

Laboratory-scale experiments have shown that treatment with selective lignin-degrading white-rot fungi improves the nutritional value and ruminal degradability of lignocellulosic biomass (LCB). However, the lack of effective field-applicable pasteurization methods has long been recognized as a major obstacle for scaling up the technique for fungal treatment of large quantities of LCB for animal feeding. In this study, wheat straw (an LCB substrate) was subjected to four field-applicable pasteurization methods - hot-water, formaldehyde fumigation, steam, and hydrated lime - and cultured with Pleurotus ostreatus grain spawn for 10, 20, and 30 days under solid-state fermentation. Samples of untreated, pasteurized but non-inoculated and fungus-treated straws were analyzed for chemical composition, aflatoxin B1 (AFB1 ), and in vitro dry matter digestibility (IVDMD), in vitro total gas (IVGP), methane (CH4 ), and volatile fatty acid (VFA) production.

RESULTS

During the 30-day fungal treatment, steam and lime pasteurized straws had the greatest loss of lignin, resulting in marked improvements in crude protein (CP), IVDMD, IVGP, and total VFAs. Irrespective of the pasteurization method, the increase in IVDMD during fungal treatment was linearly (R2  = 0.77-0.92) related to lignin-loss in the substrate during fungal treatment. The CH4 production of the fungus-treated straw was not affected by the pasteurization methods. Aflatoxin B1 was within the safe level (<5 μg kg-1 ) in all pasteurized, fungus treated straws.

CONCLUSION

Steam and lime were promising field-applicable pasteurization techniques to produce nutritionally improved fungus-treated wheat straw to feed ruminants. Lime pasteurization was more economical and did not require expensive energy inputs. © 2023 Society of Chemical Industry.

Inclusion of the fungus Pleurotus florida in the diet affects performance and feed efficiency traits in calves: a case study on Ravi buffalo

The objective of the study was to investigate the effects of inclusion of Pleurotus florida treated wheat straw in the total mixed rations (TMRs) on feed intake, growth performance, nutrient digestibility, and nitrogen retention in male buffalo calves. As a pilot study, four TMRs, i.e., TMR1 having 0% P. florida treated wheat straw (FTWS), TMR2 (20% FTWS), TMR3 (40% FTWS), and TMR4 (60% FTWS) with berseem hay as basal diet, were formulated. Sixteen Nili-Ravi male buffalo calves (aged 10-12 months, weighing 73 ± 2.50 kg) were divided into four equal groups and randomly assigned one of four TMRs. A significant increase (P < 0.05) was observed in all nutrients intake, their digestibility, weight gain, and nitrogen retention with TMRs incorporated with FTWS. Highest feed conversion ratio (FCR) of 2.63 was noted with TMR1-0% and the lowest FCR (1.80) with TMR4-60%, on the other hand. In conclusion, the TMR4 (60% FTWS) has the potential to increase the weight gain, nutrient digestibility, nitrogen retention, and feed efficiency in buffalo calves. Therefore, inclusion of 60% Pleurotus florida treated wheat straw is recommended as TMRs with berseem hay based basal diet for feeding buffaloes calves.

Improving the nutritional value and digestibility of wheat straw, rice straw, and corn cob through solid state fermentation using different Pleurotus species

BACKGROUND

The growing food-feed-fuel competition, declining availability of traditional feeds, higher prices, and the urgent need to provide long-term sustainability for animal production have all triggered global research into the optimum extraction of energy and nutrients from lignin-rich plant biomass. Recent studies have shown that the Pleurotus species of white rot fungus can selectively degrade lignin in lignin-rich plant biomass; however, its effectiveness in selectively degrading lignin depends on the type of substrate and species of fungus. This study was therefore designed to treat wheat straw, rice straw, and corn cob, with Pleurotus eryngii, P. ostreatus, and P. florida for 30 days under solid-state fermentation, to identify a promising fungus-substrate combination for the selective degradation of lignin and optimal improvement in the nutritional value and digestibility of each substrate.

RESULTS

The type of fungus strongly influenced (P < 0.01) selectivity in lignin degradation, and the level of improvement in crude protein (CP), in vitro dry matter digestibility (IVDMD), and in vitro gas production (IVGP), in wheat straw, rice straw, and corn cob. Fungus-substrate interaction data revealed that P. ostreatus caused maximum (P < 0.05) degradation of lignin, and greater (P < 0.05) improvement in CP, IVDMD, and IVGP in wheat straw and rice straw. The lowest (P < 0.05) degradation of lignin and improvement in CP, IVDMD, and IVGP was caused by P. eryngii in corn cob. Among the fungi, the maximum (P < 0.05) degradation of lignin, and greater (P < 0.05) improvement in CP, IVDMD, and IVGP were caused by P. florida as compared with those of P. ostreatus and P. eryngii.

CONCLUSION

The results highlight significant influence of fungus-substrate combination for selective lignin degradability and the consequent improvement in the nutritional value of the substrates. Maximum selective lignin degradability and improvement in nutritional value and digestibility was caused by P. ostreatus in wheat straw and in rice straw, and by P. florida in corn cob. © 2021 Society of Chemical Industry.

The sustainable mitigation of in vitro ruminal biogas emissions by ensiling date palm leaves and rice straw with lactic acid bacteria and Pleurotus ostreatus for cleaner livestock production

AIMS

The sustainable utilization of date palm leaves (DPL) and rice straw (RS) as feed materials for ruminant was evaluated using an in vitro wireless gas production technique.

METHODS AND RESULTS

Date palm leaves and RS were individually ensiled with lactic acid bacteria (LAB) for 45 d or used as substrates for the cultivation of Pleurotus ostreatus (PO) mushroom for 35 d. A total mixed ration was formulated as a control ration. In the other rations, berseem hay replaced DPL (ensiled without additives or ensiled with lactic acid bacteria or PO) at 25, 50, 75 and 100%. Ensiling with LAB did not affect the chemical composition of DPL or RS, while PO treatment reduced their fiber fractions contents. Ensiling without additives lowered (P<0.05) the asymptotic production of total gas, methane (CH₄ ) and carbon dioxide (CO₂ ), and the rate of CH₄ and CO₂ while increasing (P<0.05) the lag time of CH₄ and CO₂ production. Ensiling of materials with LAB and treatment with PO decreased (P<0.05) the asymptotic production of total gas, CH₄ and CO₂ production and decreased the rate of CH₄ and CO₂ production. Ensiling without additives decreased (P<0.05) total bacterial count, and increased (P<0.05) fermentation pH and total volatile fatty acids (VFA), while LAB ensiled DPL increased (P<0.05) total VFA and propionate concentrations and decreased total protozoal count. The PO treated DPL decreased (P<0.05) bacterial count, protozoal count and fermentation pH and increased total VFA production.

CONCLUSIONS

Replacing berseem hay with LAB or PO treated DPL at 25% increased gas production; however, increased CH₄ and CO₂ production, while the other replacement levels decreased total gas, CH₄ and CO₂ production. The treatment with LAB is more recommended than the PO treatment.

Waste-to-nutrition: a review of current and emerging conversion pathways

Residual biomass is acknowledged as a key sustainable feedstock for the transition towards circular and low fossil carbon economies to supply whether energy, chemical, material and food products or services. The latter is receiving increasing attention, in particular in the perspective of decoupling nutrition from arable land demand. In order to provide a comprehensive overview of the technical possibilities to convert residual biomasses into edible ingredients, we reviewed over 950 scientific and industrial records documenting existing and emerging waste-to-nutrition pathways, involving over 150 different feedstocks here grouped under 10 umbrella categories: (i) wood-related residual biomass, (ii) primary crop residues, (iii) manure, (iv) food waste, (v) sludge and wastewater, (vi) green residual biomass, (vii) slaughterhouse by-products, (viii) agrifood co-products, (ix) C₁ gases and (x) others. The review includes a detailed description of these pathways, as well as the processes they involve. As a result, we proposed four generic building blocks to systematize waste-to-nutrition conversion sequence patterns, namely enhancement, cracking, extraction and bioconversion. We further introduce a multidimensional representation of the biomasses suitability as potential as nutritional sources according to (i) their content in anti-nutritional compounds, (ii) their degree of structural complexity and (iii) their concentration of macro- and micronutrients. Finally, we suggest that the different pathways can be grouped into eight large families of approaches: (i) insect biorefinery, (ii) green biorefinery, (iii) lignocellulosic biorefinery, (iv) non-soluble protein recovery, (v) gas-intermediate biorefinery, (vi) liquid substrate alternative, (vii) solid-substrate fermentation and (viii) more-out-of-slaughterhouse by-products. The proposed framework aims to support future research in waste recovery and valorization within food systems, along with stimulating reflections on the improvement of resources' cascading use.

Chemical composition, ruminal degradation kinetics, and methane production (in vitro) of winter grass species

BACKGROUND

Information about the nutritive value, dry matter (DM) digestibility, and methane (CH₄ ) emission potential of grass species is required for their optimal utilization in ruminant rations. The present study was designed: (i) to quantify the nutrient profile, mineral composition and in vitro dry matter digestibility (IVDMD) of winter grass species commonly available in northern Pakistan; and (ii) to measure the in vitro gas production (IVGP) and CH₄ emission of the grass species during 72 h in vitro ruminal fermentation. Seven grass species, namely, Cenchrus ciliaris, Setaria anceps, Panicum antidotale, P. maximum, Pennisetum purpureum, Pennisetum orientale, and Atriplex lentiformis were assessed.

RESULTS

A high level of variability (P < 0.001) was observed among grass species for the content of all measured nutrients, IVDMD, IVGP, and CH₄ -production. Notably, the content (g kg^-1 DM) of crude protein varied from 59.8 to 143.3, neutral detergent fiber from 560.3 to 717.9, IVDMD from 375.1 to 576.2, and 72 h cumulative IVGP from 97.6 to 227.4 mL g^-1 organic matter (OM) and CH₄ from 48 to 67 mL g^-1 OM. Among the grasses, P. antidotale had greater content (g kg^-1 DM) of crude protein (CP) (143.3), IVDMD (576.2), and 72 h cumulative IVGP (227.4 mL g^-1 OM), and produced the smallest amount of total CH₄ (48 mL g^-1 OM) during 72 h fermentation. In contrast, A. lentiformis had the lowest content (g kg^-1 DM) of CP (59.8), IVDMD (375.1), 72 h cumulative IVGP (97.6 mL g^-1 OM), and produced a greater amount of total CH₄ (67 mL g^-1 OM) during 72 h fermentation.

CONCLUSION

The findings of the current study highlight that it is possible to select and further develop grass species with high nutritional value and lower CH₄ -production, which can improve livestock productivity, farm profitability, and long-term environment sustainability. © 2020 Society of Chemical Industry.

Effect of Irpex lacteus, Pleurotus ostreatus and Pleurotus cystidiosus pretreatment of corn stover on its improvement of the in vitro rumen fermentation

BACKGROUND

The present work investigated changes in corn stover pretreated with different white rot fungi. Corn stover was inoculated with Irpex lacteus, Pleurotus ostreatus and Pleurotus cystidiosus prior to incubation under solid-state fermentation conditions at 28 °C for 42 days. Changes in the chemical composition, in vitro rumen degradability, lignocellulolytic enzyme activity and multi-scale structure of the corn stover were analysed.

RESULTS

Content of all lignocellulose components decreased to a certain extent after fungal pretreatment. The total gas production of sterilized corn stover treated with I. lacteus for 42 days increased from 200 to 289 mL g^-1 organic matter. Moreover, the cellulase activity was highest at the later stage of I. lacteus pretreatment. Multi-scale structural analysis indicated that white rot fungal pretreatment, and in particular that of I. lacteus, increased and enlarged substrate porosity and caused changes in the structure of corn stover.

CONCLUSION

Irpex lacteus pretreatment improved the nutritional value of corn stover as a ruminant feed by degrading both cellulose and acid-insoluble lignin as well as changing the structure of the cell walls. © 2018 Society of Chemical Industry.

Potential use of cowpea (Vigna unguiculata (L.) Walp.) stover treated with white-rot fungi as rabbit feed

BACKGROUND

Lignin inhibitory effects within the cell wall structure constitute a serious drawback in maximizing the utilization of fibrous feedstuffs in animal feeding. Therefore treatments that promote efficient delignification of these materials must be applied. This study evaluated the potential of white-rot fungi to upgrade the nutritive value of cowpea stover for rabbit feeding.

RESULTS

There was an increase in the crude protein content of all substrates as a result of fungi treatments, reaching a net gain of 13% for Pleurotus citrinopileatus incubation. Overall, net losses of dry and organic matter occurred during fungi treatments. Although the fiber content remained identical, higher consumption of cell wall contents was measured for P. citrinopileatus incubation (between 40 and 45%). The incubation period did not influence lignin degradation for any of the fungi treatments. Differences within the fungal degradation mechanisms indicate that P. citrinopileatus treatment was most effective, enhancing in vitro organic matter digestibility by around 30% compared with the control.

CONCLUSION

Treatment of cowpea stover with P. citrinopileatus led to an efficient delignification process which resulted in higher in vitro organic matter digestibility, showing its potential in the nutritional valorization of this feedstuff. © 2017 Society of Chemical Industry.

Occurrence, prevention and remediation of toxigenic fungi and mycotoxins in silage: a review

Ruminants are considered to be less sensitive towards mycotoxins than monogastric animals because rumen microbiota have mycotoxin-detoxifying capacities. Therefore the effect of mycotoxins towards ruminants has been studied to a lesser extent compared with monogastric animals. Worldwide, a high proportion of the ruminant diet consists of silages made of forage crops (i.e. all parts of the crop above the stubble are harvested). In practice, silages are often contaminated with multiple mycotoxins. Exposure to a cocktail of mycotoxins can hamper animal production and have severe health consequences. In this article the different aspects associated with mycotoxin contamination of silage are reviewed 'from seed to feed'. An overview is given on the occurrence of toxigenic fungal species and their concomitant mycotoxins in forage crops before and after ensiling. The mycotoxin load of visually non-mouldy samples and mouldy hot spots within the same silo is also compared. Subsequently, this review delves into different problem-solving strategies. A logical first step is prevention of mould growth and mycotoxin production in the field, during harvest and during ensiling. If prevention should fail, several remediation strategies are available. These are listed, mainly focusing on the possibilities of microbial degradation of mycotoxins in vivo in silage. © 2015 Society of Chemical Industry.