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Bio-fermentation technology has been successfully developed for ensiling rice straw; however, its effects on the particle-attached microbial community remains unknown. Therefore, rice straw (RS) and bio-fermented rice straw (BFRS) were used as substrates for in vitro rumen fermentation to investigate the effect of bio-fermentation on particle-attached microbial community, as well as their effects on gas and methane production, fermentation products, and fiber degradation. Our results have shown that total gas production, fiber degradation, and in vitro fermentation products were significantly higher (p < 0.05) for the BFRS than the RS, while methane concentration in total gas volume was significantly lower (p < 0.05) for the BFRS than RS. Linear discriminant effect size (LefSe) analysis revealed that the relative abundance of the phyla Bacteroidetes, Fibrobacteres, Proteobacteria, and Lantisphaerae, as well as the genera Fibrobacter, Saccharofermentans, and [Eubacterium] ruminantium groups in the tightly attached bacterial community, was significantly higher (p < 0.05) for the BFRS than the RS, whereas other microbial communities did not change. Thus, bio-fermentation altered the tightly attached bacterial community, thereby improving gas production, fiber degradation, and fermentation products. Furthermore, bio-fermentation reduced methane concentration in total gas volume without affecting the archaeal community.

The nutritional properties of brewers' spent grain (BSG) have been widely studied, considering its potential as a healthy food ingredient. Because of its fiber composition (amount and ratio), however, adding BSG into the food matrix to bring about changes in physical properties has been believed to impact negatively on the acceptability of the final products' properties, particularly color and texture. Fiber modification can enhance the quality of fiber and can be applied to BSG. Although it appears challenging, modifying fiber composition requires further study, particularly if the acceptability of the final products is to be improved. Furthermore, the level of fiber degradation during the modification treatment needs to be examined to meet the increased demand for BSG in final food products. This concise synthesis provides a new perspective for increasing the use of BSG as a food ingredient that is characterized by high nutrition and acceptability.

In order to study the potential for efficient fiber degradation by intestinal microorganisms in Diqing Tibetan pigs, we first investigated the dietary structure of Diqing Tibetan pigs in their original habitat, then 60 healthy adult Diqing Tibetan pigs were randomly divided into 2 groups with 6 replicates each and 5 pigs in each replicate. The content of neutral detergent fiber in treatment 1 and 2 were adjusted to 20% and 40%, respectively. The total tract digestibility of nutrients and the degradation efficiency of fecal microorganisms to different types of fiber were determined. Results showed that the composition and nutritional level of Diqing Tibetan pig original diet differed greatly in different seasons. The content of crude fiber in the original diet was as high as 12.3% and the neutral detergent fiber was 32.5% in April, while the content of crude fiber was 4.9% and the neutral detergent fiber was 13.3% in October. With the increase of dietary fiber level, the total tract apparent digestibility of dry matter, crude fiber, crude protein, acid detergent fiber, neutral detergent fiber, ether extract, and organic matter decreased significantly (p < 0.05), and the contents of acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, and isovaleric acid in the feces were also significantly (p < 0.05) reduced. The ability of Diqing Tibetan pig fecal microorganisms to degrade neutral detergent fiber was significantly higher (p < 0.05) than “Duroc × Landrace × Yorkshire” pig. In addition, there was no significant difference (p > 0.05) in the degradation efficiency of the same type of fiber between NDF-20 and NDF-40 groups. Our results strongly suggested that Diqing Tibetan pigs have the potential to efficiently utilize fiber, and their unique intestinal microbial composition is the main reason for their efficient utilization of dietary fiber.

The addition of soy sauce residue (SSR) during soybean paste fermentation usually reduces the flavor quality due to high content of fibers. Steam explosion (SE) pretreatment is an effective way to promote the fiber degradation. In this study, SE-pretreated SSR was investigated and exploited during soybean paste fermentation. SE pretreatment increased the numbers of holes and the surface irregularity, resulting in a more pronounced wrinkled surface and looser internal structure than other pretreatments. Over half of cellulose and 10 percentage of hemicellulose were released from the dense structure of SE-pretreated SSR. The addition of 3–10 percentage of the SE-pretreated SSR was more suitable for soybean paste fermentation. The flavor formation of SSR during soybean paste fermentation was enhanced by SE pretreatment. In brief, SE pretreatment of SSR improve the quality of soybean paste.

Plants contain a large number of secondary compounds which are not required for the primary activities of plants but act as a defense against pathogenic microbes and dust particles. These plant secondary metabolites (PSM) include saponins, tannins, essential oils, alkaloids, terpene compounds, etc. These PSM have strong anti-methanogenic activity, and a few of them have also fiber degradation stimulating activity, but many of these have no effect on feed degradation or have an adverse effect on nutrient release. A proper combination of these PSM might have a balanced activity against methane inhibition and improve fiber degradation, making the process of livestock production economic and eco-friendly.

Nine samples of pure stand alfalfa hay, representative of the compositional variability found in Mediterranean and Intermountain West climates, were collected throughout California and western Nevada during the 2008 growing season. Samples were evaluated in vivo (at either maintenance or ad libitum intakes by lambs), in vitro, in silico, and by near infrared spectrophotometry to determine characteristics of DM and fiber degradation as well as energy metabolizability. Also determined, from these and other routine analyses, were common indices of alfalfa quality including relative feed quality, relative feed value, in vivo TDN and ME. Significant differences (P < 0.05) in observed ME (Mcal/kg) were noted for alfalfa hays depending on source; quality indices were compared with observed ME. None of the indices evaluated were valid predictors of observed ME (P < 0.050), with the exception of near infrared predicted ME at either level of intake. Users of quality indices may expect less than optimal prediction of animal performance from use of indices or calculations based on indices failing to accurately predict ME. Results from this study indicate that ME estimated from near infrared spectrophotometry of pure stand alfalfa hay may improve characterization of alfalfa hay quality in that, depending on the feeding standard, ME input explains the vast majority of variation in animal output. However, given the limited numbers of alfalfa hay samples evaluated in this study, more studies are required.

Reducing livestock negative environmental impacts get great interest in last years. So, present study was carried out to determine the effect of adding different levels of mixture of thyme and celery versus salinomycin on ruminal fermentation, gas production, dry, organic matter and fiber degradation. Four experimental treatments were used by in-vitro batch culture technique, as follow: 60% CFM, 40% clover hay (control), control diet + 2.5 gm thyme + 2.5 gm celery kg-1 DM (T1), control diet + 5 gm thyme + 5 gm celery kg-1 DM (T2), control diet + 10 gm thyme + 10 gm celery kg-1 DM (T3), control diet + 0.4 gm Salinomycin kg-1 DM (T4). Ruminal pH value was significantly increased (p < 0.05) with T4 compared with other treatments. While, the T4 recorded the lowest value (p < 0.05) for microbial protein, short chain fatty acids concentrations (SCFA), total gas production, dry matter and organic matter degradability (DMd and OMd) compared with other treatments. Fiber fraction degradability (NDFd and ADFd) appeared no significant variance (p > 0.05) between control and other treatments except for T1 that recorded the lowest value (p < 0.05). It is concluded that mixture of thyme plus celery could be alternate for ionophores in the ruminant diets to enhance ruminal fermentation, reducing gas production without any negative effect on nutrients degradability. Reducing livestock negative environmental impacts get great interest in last years. So, present study was carried out to determine the effect of adding different levels of mixture of thyme and celery versus salinomycin on ruminal fermentation, gas production, dry, organic matter and fiber degradation. Four experimental treatments were used by in-vitro batch culture technique, as follow: 60% CFM, 40% clover hay (control), control diet + 2.5 gm thyme + 2.5 gm celery kg-1 DM (T1), control diet + 5 gm thyme + 5 gm celery kg-1 DM (T2), control diet + 10 gm thyme + 10 gm celery kg-1 DM (T3), control diet + 0.4 gm Salinomycin kg-1 DM (T4). Ruminal pH value was significantly increased (p < 0.05) with T4 compared with other treatments. While, the T4 recorded the lowest value (p < 0.05) for microbial protein, short chain fatty acids concentrations (SCFA), total gas production, dry matter and organic matter degradability (DMd and OMd) compared with other treatments. Fiber fraction degradability (NDFd and ADFd) appeared no significant variance (p > 0.05) between control and other treatments except for T1 that recorded the lowest value (p < 0.05). It is concluded that mixture of thyme plus celery could be alternate for ionophores in the ruminant diets to enhance ruminal fermentation, reducing gas production without any negative effect on nutrients degradability.

The success of livestock business is influenced by the feeding cost which will affect production costs, Therefore, it is needed to find an alternative feeds which has high quality content with relatively low prices. Coconut dregs can be used as an alternative to livestock feeds, but it has high fiber content, so it has low digestibility. It is necessary to conduct a processing of coconut dregs by using fermentation with fiber degradating bacteria. The purpose of this research was to determine fiber content changes (NDF, ADF, and hemicellulose) in coconut dregs after experiencing fermentation process using fiber degradating bacteria from PLIEK U. The method used complete random factorial which was designed with two different factors and three replications. The results of analysis of NDF, ADF and hemicellulose showed that there were interactions on both factors, the highest fiber content (NDF, ADF, and hemicellulose) is on the interaction of P1W1 (1% and 3 days), and the lowest fiber content (NDF, ADF, and hemicellulose) was on the interaction of P3W3 (5% and 9 days). It was concluded that the fermentation of coconut dregs using bacteria from PLIEK U could degrade the fiber content of coconut dregs, the more bacteria given and the longer the incubation time, so the fiber content (NDF, ADF, and hemicellulose) more decrease, and the best fermentation treatment was found in P3W3 interactions that was fermentation with 5% inoculum and 9 days incubation.

The aim of this study was to improve the utilization of rice straw as forage in ruminants by investigating the degradation pattern of rice straw in the dairy cow rumen. Ground up rice straw was incubated in situ in the rumens of three Holstein cows over a period of 72 h. The rumen fluid at 0 h and the rice straw at 0.5, 1, 2, 4, 6, 12, 24, 48, and 72 h were collected for analysis of the bacterial community and the degradation of the rice straw. The bacterial community and the carbohydrate-active enzymes in the rumen fluid were analyzed by metagenomics. The diversity of bacteria loosely and tightly attached to the rice straw was investigated by scanning electron microscopy and Miseq sequencing of 16S rRNA genes. The predominant genus in the rumen fluid was Prevotella, followed by Bacteroides, Butyrivibrio, unclassified Desulfobulbaceae, Desulfovibrio, and unclassified Sphingobacteriaceae. The main enzymes were members of the glycosyl hydrolase family, divided into four categories (cellulases, hemicellulases, debranching enzymes, and oligosaccharide-degrading enzymes), with oligosaccharide-degrading enzymes being the most abundant. No significant degradation of rice straw was observed between 0.5 and 6 h, whereas the rice straw was rapidly degraded between 6 and 24 h. The degradation then gradually slowed between 24 and 72 h. A high proportion of unclassified bacteria were attached to the rice straw and that Prevotella, Ruminococcus, and Butyrivibrio were the predominant classified genera in the loosely and tightly attached fractions. The composition of the loosely attached bacterial community remained consistent throughout the incubation, whereas a significant shift in composition was observed in the tightly attached bacterial community after 6 h of incubation. This shift resulted in a significant reduction in numbers of Bacteroidetes and a significant increase in numbers of Firmicutes. In conclusion, the degradation pattern of rice straw in the dairy cow rumen indicates a strong contribution by tightly attached bacteria, especially after 6 h incubation, but most of these bacteria were not taxonomically characterized. Thus, these bacteria should be further identified and subjected to functional analysis to improve the utilization of crop residues in ruminants.

Nitrate decreases enteric CH4 production in ruminants, but may also negatively affect fiber degradation. In this experiment, 28 lactating Holstein dairy cows were grouped into 7 blocks. Within blocks, cows were randomly assigned to 1 of 4 isonitrogenous treatments in a 2×2 factorial arrangement: control (CON); NO3 [21g of nitrate/kg of dry matter (DM)]; DHA [3g of docosahexaenoic acid (DHA)/kg of DM]; or NO3+DHA (21g of nitrate/kg of DM and 3g of DHA/kg of DM). Cows were fed a total mixed ration consisting of 21% grass silage, 49% corn silage, and 30% concentrates on a DM basis. Based on the difference in natural (13)C enrichment and neutral detergent fiber and starch content between grass silage and corn silage, we investigated whether a negative effect on rumen fiber degradation could be detected by evaluating diurnal patterns of (13)C enrichment of exhaled carbon dioxide. A significant nitrate × DHA interaction was found for neutral detergent fiber digestibility, which was reduced on the NO3 treatment to an average of 55%, as compared with 61, 64, and 65% on treatments CON, DHA, and NO3+DHA, respectively. Feeding nitrate, but not DHA, resulted in a pronounced increase in (13)C enrichment of CO2 in the first 3 to 4 h after feeding only. Results support the hypothesis that effects of a feed additive on the rate of fiber degradation in the rumen can be detected by evaluating diurnal patterns of (13)C enrichment of CO2. To be able to detect this, the main ration components have to differ considerably in fiber and nonfiber carbohydrate content as well as in natural (13)C enrichment.

Apparel textiles in service will adsorb metabolism perspiration from human body, thus prompting microbial propagation and leading to fiber degradation and splash. More seriously, this microbe gives rise to allergy and red swelling on human skin, which makes our body unwell. Staphylococcus aureus is one of common bacteria on human skin, but its excessive breeding on skin will bring red swelling and inflammation. In order to avoid this situation happening, we add antibacterial ingredients in textiles which were not harmful to human and cannot have negative effect on human. And this study aims at seeking for anti-staphylococcus aureus plants, trying to add ingredients from plants in textiles to discuss their antimicrobial change and investigating whether to be potential in textiles application. Phyllanthus Urinaria Linn (PUL) is common in tropical East Asia and can suppress the growth of bacteria regarding staphylococcus aureus, typhoid bacillus, pseudomonas aeruginosa etc. It is shown that when PUL was treated at 60°C for 6 hours in 300 ml 95 % ethyl alcohols, extract rate was up to 12.53 %. And qualitative antimicrobial was effective between 12g/100ml and 0.09375g/100ml PUL extract liquor. And the fabric qualitative antimicrobial was obviously valid when extract concentration was above 0.75g/100 ml. Therefore, cotton treated by 1.5g/100ml PUL extract liquor had prominent antimicrobial effect.

Sixty-four male Holstein-Friesian x Dutch Friesian veal calves (46 +/- 3.0 kg) were used to evaluate the effect of the inclusion of different levels and sources of dietary roughage on animal performance and rumen development. Treatments consisted of 1) C100 = concentrate only; 2) C70-S30 = concentrate (70%) with straw (30%), 3) C70-G30 = concentrate (70%) with dried grass (30%), 4) C70-G15-S15 = concentrate (70%) with dried grass (15%) and straw (15%), 5) C70-CS30 = concentrate (70%) with corn silage (30%), 6) C40-CS60 = concentrate (40%) with corn silage (60%), 7) C70-CS30-AL = concentrate (70%) with corn silage (30%) ad libitum, 8) C70-G15-S15-AL = concentrate (70%) with dried grass (15%) and straw (15%) ad libitum. All dietary treatments were provided in addition to a commercial milk replacer. Concentrate was provided as pellets and roughage was chopped. The dietary treatments 1 to 6 were supplied restrictedly to a maximum of 750 g of dry matter (DM) per day, whereas treatments 7 and 8 were offered ad libitum in combination with a reduced amount of milk replacer. Calves were euthanized after 10 wk. Straw supplementation (C70-S30 vs. C70-G30 and C70-CS30) reduced DM intake, and ad libitum supply of concentrate and roughage increased DM intake. Roughage addition did not affect growth performance. Rumen fermentation was characterized by low pH and high total volatile fatty acids and reducing sugar concentrations. Calves fed ad libitum showed lower ruminal lactate concentrations than calves fed restrictedly. Ammonia concentrations were highest in calves fed C-100 and lowest in calves fed ad libitum. The recovery of CoEDTA (added to milk replacer) varied between 20.5 and 34.9%, indicating that significant amounts of milk entered the rumen. Roughage addition decreased the incidence of plaque formation (rumen mucosa containing focal or multifocal patches with coalescing and adhering papillae covered by a sticky mass of feed, hair and cell debris) and the incidence of calves with poorly developed rumen mucosa. However, morphometric parameters of the rumen wall were hardly influenced by the type and level of roughage. Ruminal polysaccharide-degrading enzyme activities reflected the adaptation of the microorganisms to the dietary concentrate and roughage source. Results indicated that in veal calves, the addition of roughage to concentrate diets did not affect growth performance and positively influenced the macroscopic appearance of the rumen wall.

Daily additions of 3 g of Amaferm to alfalfa (13% CP) and bromegrass (6% CP) diets were evaluated for effects on ruminal and postruminal fiber and organic matter digestion, fermentation profile, and duodenal bacterial nitrogen flow. Eight beef cows were fitted with ruminal and duodenal cannulas. Two experiments were conducted. Eight cows were fed bromegrass hay, four received Amaferm and four served as controls; later, seven cows received alfalfa hay with three receiving Amaferm and four serving as controls. Each experiment lasted 28 d: d 1 to 14 for adaptation, d 15 to 21 for measurement of feed intake, and d 22 to 28 for ruminal and duodenal sampling. Dacron bags containing NDF substrate from alfalfa or bromegrass were used to determine ruminal fiber degradation at 3, 6, 9, 12, 24, 48, and 72 h. There were no Amaferm effects (P > .15) on rate or extent of fiber degradation in situ when bromegrass of alfalfa was fed. There were no Amaferm effects (P > .10) on concentrations or molar proportions of ruminal VFA, pH, or NH3 or on feed intake in either experiment. There were no effects (P > .10) of Amaferm on site or extent of organic matter or fiber digestion, or duodenal nitrogen flow in cows fed either bromegrass or alfalfa. Amaferm increased (P < .10) the number of ruminal anaerobic bacteria in cows fed bromegrass but not in those fed alfalfa.(ABSTRACT TRUNCATED AT 250 WORDS)

Anaerobic fungi inhabit the rumen and actively degrade plant cell walls. Rumen fungi produce high levels of cellulases and hemicellulases and are particularly proficient in producing xylanases. These enzymes are regulated by substrate (especially soluble sugars) available to the organisms. Fungi degrade unlignified (i.e., no histochemical reaction for phenolics) plant walls totally, indicating that enzymes are able to hydrolyze or solubilize the entire plant wall. These organisms are better able to colonize and degrade the lignin-containing tissues than are bacteria; phenolics are solubilized but not metabolized from the plant wall by fungi. Anaerobic fungi are unique among rumen microorganisms in that they penetrate the cuticle. Residues after incubation with fungi are physically weaker than those incubated with whole rumen fluid or with rumen bacteria, suggesting that fungi could alter the fibrous residue for easier mastication by the animal. Data indicate that cocultures of anaerobic fungi with methanogenic bacteria stimulate cellulose degradation; other data suggest that fungi are inhibited by certain rumen microorganisms. The interaction of rumen fungi with other organisms in relation to fiber degradation in the rumen requires additional study. Rumen fungi have the potential to degrade the more recalcitrant plant walls in forages, but this potential is not always reached in the rumen.

Eight cows (7 to 9 yr old, 522 kg) and six heifers (10 mo old, 169 kg) were fed either alfalfa hay (18.7% CP) or mature brome hay (5.1% CP) to determine the effect of cattle age on apparent forage utilization. Cattle were fitted with ruminal and duodenal cannulas and were individually fed once daily (ad libitum intake, 1000). The split-plot design consisted of age (whole-plot) and two sampling periods feeding alfalfa or brome hay (subplot). Each period consisted of 28 d: d 1 to 13 for adaptation, d 13 to 20 for feed intake determination, and d 20 to 28 for sampling. Nylon bags containing NDF substrate from alfalfa or brome hay were incubated ruminally for 0, 3, 6, 12, 24, 48, 96, and 192 h to determine the rate and extent of fiber degradation. Ruminal liquid dilution rate and fermentation characteristics were conducted on d 27. Ruminal fill was determined by total evacuation at 0800 on d 28. Cows consumed more feed (BW.75; P.01) and had greater ruminal OM fill (P = .04) but had similar fluid fill (P = .88) compared with heifers. Ruminal liquid dilution rate was greater in cows than in heifers (P.01). The rate of in situ NDF degradation was 3 and .5% per hour greater in cows than in heifers when alfalfa and brome hay were fed, respectively (age x hay, P.01). Ruminal NDF digestibility as a percentage of intake was greater in cows than in heifers (P.01). Numbers of ruminal cellulolytic bacteria were not affected by treatment (P.21). These data indicate that mature cows have a smaller ruminal fluid fill that turns over more rapidly, and this may be responsible for a faster rate of ruminal fiber degradation in cows than in young heifers.

Fiber fermentation using the in situ bag technique was studied in a hay-fed cow. Entry of fine particles into bags of varying pore size, the effect of sample size, rumen contractions, bag porosity and rumen contraction (bags suspended in vitro or in situ) and obstruction of liquid flow through the bag cloth were investigated (Exp. 1). In Exp. 2 fiber degradation in vitro and in situ with 5- and 37-micron pore size bags was measured utilizing six fistulated heifers (four large: 610 kg and two small: 243 kg), two sheep and two goats (30 kg), three ponies (130 kg) and four rabbits (3.2 kg). Degradation rate (k) and indigestible fiber (B) were determined after curve fitting. Lag of fermentation was also calculated. Results of Exp. 1 showed that plant fiber containing approximately 50% lignin and 2.9% N entered even 20-micron pores, that rumen contractions increased fiber disappearance and that obstructing liquid exchange limited fermentation. Results of Exp. 2 showed lower fiber residues for 37-micron than for 5-micron pore size bags and that in situ method, time and species were highly significant (P less than .0001). All model factors differed significantly among species (P less than .05), but not among the three methods. Lag approached significance for methods (P = .07), but not for species. In situ measurements (37-micron) resulted in the following values for k (h-1), B (%) and lag (h): large heifers .040, 39 and -1; small heifers .025, 39 and 0; sheep-goats .051, 42 and 2; ponies .030, 59 and -5 and rabbits .107, 85 and 3.

The aim of this experiment was to examine the effects of concentrates in feed, differing in carbohydrate source, on the growth performance and rumen fermentation characteristics of veal calves. For this purpose, 160 Holstein Friesian x Dutch Friesian crossbred male calves were used in a complete randomized block design with a 5 x 2 factorial arrangement. Dietary treatments consisted of 1) milk replacer control, 2) pectin-based concentrate, 3) neutral detergent fiber-based concentrate, 4) starch-based concentrate, and 5) mixed concentrate (equal amounts of concentrates of treatments 2, 3, and 4). Concentrate diets were provided as pellets in addition to a commercial milk replacer. Calves were euthanized either at the end of 8 or 12 wk of age. The overall dry matter intake of the concentrate diets varied between 0.37 and 0.52 kg/d. Among the concentrate diets, the dry matter intake was lower in the starch diet (0.37 kg/d of dry matter) and differed between the NDF and pectin diets. The average daily gain for all the dietary treatments varied between 0.70 and 0.78 kg/d. The mixed- and NDF-fed calves had an increased average daily gain (0.78 and 0.77 kg/d, respectively) compared with the starch- and pectin-fed calves (0.70 and 0.71 kg/d, respectively). Rumen fermentation in the calves fed concentrates was characterized by a low pH (4.9 to 5.2), volatile fatty acid concentrations between 100 and 121 mmol/L, and high concentrations of reducing sugars (33 to 66 g/kg of dry matter). The volatile fatty acid concentrations of calves fed concentrates were higher than those of the control calves. All concentrate treatments showed a low acetate-to-propionate ratio in rumen fluid (between 1.3 and 1.9). Among the concentrates, the NDF diet had the highest (55.5%) and starch the lowest (45.5%) molar proportions of acetate. Calves fed the mixed, pectin, and starch diets had significantly higher molar proportions of butyrate (13.1 to 15.8%) than the NDF- and control-fed groups (9.9 and 9.6%, respectively). Calves fed the control diet had a higher lactate concentration (21 mmol/L) than the concentrate-fed calves (between 5 and 11 mmol/L). With the exception of the NDF diet, polysaccharide-degrading enzyme activities in the rumen contents generally showed an adaptation of the microorganisms to the carbohydrate source in the diet. The mixed diet exhibited the least variation in rumen polysaccharide-degrading enzyme activities among the enzymes systems tested. Results indicated that the carbohydrate source can influence intake, growth rate, and rumen fermentation in young veal calves.

In the last five decades, attempts have been made to improve rumen fermentation and host animal nutrition through modulation of rumen microbiota. The goals have been decreasing methane production, partially inhibiting protein degradation to avoid excess release of ammonia, and activation of fiber digestion. The main approach has been the use of dietary supplements. Since growth-promoting antibiotics were banned in European countries in 2006, safer alternatives including plant-derived materials have been explored. Plant oils, their component fatty acids, plant secondary metabolites and other compounds have been studied, and many originate or are abundantly available in Asia as agricultural byproducts. In this review, the potency of selected byproducts in inhibition of methane production and protein degradation, and in stimulation of fiber degradation was described in relation to their modes of action. In particular, cashew and ginkgo byproducts containing alkylphenols to mitigate methane emission and bean husks as a source of functional fiber to boost the number of fiber-degrading bacteria were highlighted. Other byproducts influencing rumen microbiota and fermentation profile were also described. Future application of these feed and additive candidates is very dependent on a sufficient, cost-effective supply and optimal usage in feeding practice.