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Cattle feeding in South Korea has been heavily dependent on domestically produced rice straw and imported grain. Around 42% of domestically produced rice straw is utilized for forage, and the remainder is recycled to restore soil fertility. Approximately 35% of round baleages were made with rice straw. However, higher quality hay is desired over rice straw. Due to increasing stockpiles of rice, there has been an economic burden on the government to store the surplus; therefore production of annual forage crops in rice fields has been further promoted in recent years. Hay import from the USA currently constitutes more than 80% of total imported hays. The main imported hays are alfalfa (Medicago sativa), timothy (Phleum pretense), and tall fescue (Festica arundinacea). The estimated forage required for cattle feeding was approximately 5.4 million MT in 2016. Domestically produced forage sates only 43% of that value, while low quality rice straw and imported hay covered the rest of demand by 33% and 20%, respectively. As utilization of domestically produced forage is more desirable for forage-based cattle production, long-term strategies have been necessary to promote domestic production of high quality baleage. One such strategy has been utilizing the fertile soil and abundance of fallow rice fields of western region of S. Korea to produce forage crops. Italian ryegrass (Lolium multiflorum) is the most successfully produced winter annual in the region and is approximately 56% of the total winter annual forage production. Forage sorghums (Sorghum bicolor), sorghum × sudangrass hybrids, and hybrid corn (Zea mays) produce a substantial amount of warm-season forage during summer. Produced forage has been largely stored through baleage due to heavy dew and frequent rains and has been evaluated according to S. Korea’s newly implemented baleage commodity evaluation system. The system weighs 50% of its total grading points on moisture content because of its importance in deliverable DM content and desirable baleage fermentation; this has proved to be an effective method. Although further improvement is required for the future of forage production in South Korea, the current government-led forage production in rice fields has been able to alleviate some of the country’s shortage for quality hay.

Fall- or spring-born steers grazed monoculture irrigated birdsfoot trefoil (BFT; Lotus corniculatus L.) or cicer milkvetch (CMV; Astragalus cicer L.) pastures for approximately 12 weeks for 3 years and were compared with steers on concentrate diets. In the 3rd year, an irrigated meadow bromegrass (MBG; Bromus biebersteinii Roem. and Schult.) pasture treatment was added for further comparison. Steer average daily gain (ADG) was 1.31, 0.94, 0.83 and 0.69 kg d−1 on concentrate, ‘Norcen’ BFT, ‘Oberhaunstadter’ BFT, and ‘Monarch’ CMV diets, respectively; ADG on grass pastures was 0.43 kg d−1. The ADG on the concentrate diet was greater than ADG on legume or grass pastures, ADG was greater on BFT than CMV in every year (p < 0.03), and ADG on BFT was greater than ADG on grass (p < 0.03). The rate constant of gas production of an in vitro rumen fermentation demonstrated a slower rate of microbial digestion for CMV than for BFT. The elevated ADG on BFT pastures may be due to greater non-fiber carbohydrate (NFC) concentration and reduced neutral detergent fiber (NDF) concentration combined with condensed tannins that protect proteins in the rumen but do not impede protein digestion in the abomasum and intestines.

Over-seeding cool-season annual forages in pastures in the southeastern US provides increased grazing opportunities for livestock and reduces the amount of hay needed during winter. The constant presence of vegetation can benefit soil health, the biological aspect of which has only received cursory investigation to date. Since 2009, a commercial cattle grazing operation located in south Mississippi has been over-seeding a diverse mixture of oats (Avena sativa L.), triticale (X Triticosecale Wittmack), annual ryegrass (Lolium multiflorum Lam.), hairy vetch (Vicia villosa Roth), radish (Raphanus sativus L.), turnips (Brassica rapa L. subsp. rapa), red clover (Trifolium pratense L.), ball clover (Trifolium nigrescens Viv.), and crimson clover (Trifolium incarnatum L.) into pastures dominated by bahiagrass (Paspalum notatum Flugge). Soil health properties were assessed across a heterogeneous landscape from soils collected immediately prior to seeding and following increased spring productivity of cool-season annuals from 2015 to 2017. Samples were collected across a topographic sequence to a depth of 15 and 30 cm. Three samples per site were collected from summit, backslope, and footslope locations. Soil chemical assessments included macronutrients, pH, soil organic matter (SOM), total carbon (TC), and total nitrogen (TN). Fatty acid methyl ester analysis and enzyme assays were used to determine soil microbial community structure and activity. While TC and TN did not change with time (20.5 and 2.4 g kg−1, respectively), SOM increased by 6% from 2015 to 2017. Nitrate-N decreased by 82% from 2015 to 2017. N-acetyl-β-glucosaminidase activity increased by 32%, while β-glucosidase remained constant. Total microbial abundance did not change with time; however, Gram positive bacteria and actinomycetes decreased by 51% and 43%, respectively, from fall to spring. Arbuscular mycorrhizal fungi increased from fall to spring by an average of 45%. This pasture management technique of over-seeding a diverse mix of winter annuals may have resulted in a steady state of TC and TN, while SOM increased and inorganic nitrogen decreased with time, and enhanced the total soil microbial community particularly fungi and their potential enzyme activity. Despite some biological indications of system stability, soil properties potentially limiting to plant growth were identified for some sites, but these limitations were not closely related to topographic position as expected.

Cup plant (Silphium perfoliatum L.) may serve as an alternative perennial forage crop in lowlands of the north central United States. Three feeding trials were conducted with Holstein cows (Bos taurus) at the early, mid, and late lactation stages to evaluate the impact of different cup plant silage substitution levels for alfalfa (Medicago sativa L.)-corn (Zea mays L.) silage mixture on milking cow performance. The concentrations of lignin and CP (crude protein) in the first cut and regrowth cup plant silage were lower than alfalfa silage. Substituting one-half of the silage reduced voluntary dry matter (DM) intake of early lactation stage cows by 11%. Although milk composition was not changed by the substitution, the 4% FCM (fat corrected milk) production was reduced by 7.5%. Another feeding trial tested substitution of one-third and two-thirds of the silage for mid-lactation cows. Increasing cup plant silage up to two-thirds of the forage portion in the diet reduced DM intakes and 4% FCM production by 21.8 and 8.7%, respectively. Milk composition did not change. Cow bodyweight was reduced as the substitution rate increased. Finally, a feeding trial with late-lactation cows indicated substitution of one-fourth of the silage performed equivalent in DM intake, milk composition, and milk production to those of cows fed a low forage diet (50% alfalfa-corn silage in diet), or a high forage diet (66% alfalfa-corn silage in diet). Based on the results of the three feeding trials, it is concluded that cup plant silage can substitute mixture of alfalfa-corn silage at up to 30% of the forage portion in diets without substantial negative impacts on the performance of dairy cows, especially during late lactation.

Biochar has been suggested as new adsorbent for removing heavy metals from aqueous solutions. However, adsorption nature of biochar is influenced by feedstock-specific properties. In this study, experiments were performed to characterize the effect of cation exchange on adsorption behavior of Cu and Zn in single- and binary-metal systems by rice straw biochar (RSB) made by pyrolysis at 600 °C. Result of kinetic experiment showed that the Cu and Zn in aqueous solution were rapidly adsorbed from the RSB in the first 2 h and then reached the equilibrium after 4 h. The fitting of intraparticale diffusion model showed fast Cu diffusion into boundary layer and pores of biochar than Zn. In parallel with 2.65 meq L−1 Cu and 1.79 meq L−1 Zn being adsorbed by RSB, up to 1.65 and 0.76 meq L−1 exchangeable cations were released into the solution, indicating that cation exchange could contribute 62.3 and 42.5% to Cu and Zn sorption by RSB. Langmuir maximum adsorption capacities (a) of RSB for Cu and Zn were 56.5 and 38.6 mg g−1 in single-metal system and 40.2 and 7.9 mg g−1 in binary-metal system, respectively. Overall, the results demonstrate that the Cu and Zn adsorption by RSB was closely related to the exchangeable cation. The application of RSB could be especially attractive when considering biochar with high cation exchange capacities.

Summary Efficient ethanol production from lignocellulosic biomass requires highly degradable feedstock; therefore, there is a similarity between forage crop production for ruminant animals and ethanol production from lignocellulosic biomass. Feed value analysis techniques may be used to estimate lignocellulosic biomass quality. Because lignin and its derivatives in cell walls are major compounds interrupting biomass degradation, fiber analysis and in vitro incubation tests were conducted with switchgrass (Panicum virgatum) and energycane (Saccharum spp.) biomass collected at 100 and 120 g lignin (acid detergent lignin) kg−1 DM (dry matter). Mean NDF (neutral detergent fiber) in switchgrass was consistently greater than that of energy cane regardless of lignin levels, while ADF (acid detergent fiber) did not differ. Mean of energycane in vitro true digestibility and digestible neutral detergent fiber were greater than those of switchgrass. The ADF and ruminal fermentation rate averaged by lignin levels differed, while most of the analysis results did not. Based on ADF and NDF concentrations, switchgrass contained a greater concentration of hemicellulose than energycane, while cellulose concentration was similar. Fermentability of energycane was consistently greater than that of switchgrass. Fermentation gas volume was positively correlated with cellulosic biomass degradation for ethanol production. Consequently, fermentation gas kinetic parameters obtained from biomass fermentation with rumen fluid or with yeast indicate that the fermentable pool size is the parameter most closely correlated to ethanol production potential across the species. Results obtained from feed value analyses demonstrate fermentation variability and meaningful relationships between fermentation gas parameters and ethanol production. Thus, the ruminal fermentation process is useful as a screening tool for ethanol production potential of biofuel feedstock. Copyright © 2015 John Wiley & Sons, Ltd.

Sugarcane molasses was studied as a substrate for butanol and isopropanol fermentation by Clostridium beijerinckii optinoii in 10 L batch fermentations. Using 3% glucose as a carbon source, the solvent concentrations (butanol and isopropanol) and solvent yields were 10.03 g/L and 0.43 g/g, respectively, with a sugar utilization of 81.7%. However, on 2.5% glucose medium supplemented with an additional 0.5% sugar supplied as sugarcane molasses, sugar consumption was 100% and the solvent concentrations (13.37 g/L) and solvent yields (0.45 g/g) were both higher. Sugarcane molasses (3%) with or without invertase and without P2 vitamin/mineral solution produced a solvent concentration of 12.15 ~ 12.81 g/L and solvent yield of. 0.39 ~ 0.41 g/g with sugar consumption of 94.88 ~ 100%. This work demonstrated the value of sugarcane molasses as a supplementary nutrient for glucose fermentation for butanol and isopropanol production using C. beijerinckii optinoii as well as its value as a low cost carbon and media source.

Sweet sorghum [Sorghum bicolor (L.) Moench] is recognized as a promising biomass energy crop for meeting the increasing demand for bioenergy feedstocks. Field experiments were conducted at sites in northern and southern Louisiana for 2 yr to assess planting date and harvest maturity effects on yield from primary plantings and ratoon crops. The cultivar M81-E was evaluated using a split plot arrangement of treatments in randomized complete block designs. Planting date from mid-March to early July was the primary plot treatment. Harvest maturity at the early heading (EH) or hard dough (HD) stage was assigned as the subplot treatment. A range of planting dates from mid-March to early June produced substantial yields of biomass and fermentable sugar with appropriate harvest maturity and could support sugar mill operation for up to three additional months. However, sweet sorghum planted in early May and harvested at the HD stage produced 30 to 210% more fermentable sugar than other tested planting dates and maturity combinations. Ratoon crop production was not dependable showing inconsistent tiller growth with resultant low biomass yields. Correlation coefficients of sugar yield with biomass or other quantitative agronomic characteristics were higher than 0.79, while that with brix was only 0.32 (P < 0.0001). Production management in Louisiana from long season cultivars such as M81-E based on a single harvest 150 to 160 d from planting at the HD stage can provide more biomass and fermentable sugar than can production management targeting a ratoon crop.

Sweet sorghum (Sorghum bicolor (L.) Moench) is widely recognized as a highly promising biomass energy crop with particular potential to complement sugarcane production in diversified cropping systems. Agronomic assessments have led to identification of four cultivars well suited for such sugarcane-based production systems in southern Louisiana. Sweet sorghum biofuel production systems are currently being developed, and research producing large sample numbers requiring ethanol yield assessment is anticipated. Fiber analysis approaches developed for forage evaluation appear to be useful for screening such large numbers of samples for relative ethanol yield. Chemical composition, forage fiber characteristics, digestibility, and ethanol production of sweet sorghum bagasse from the four cultivars were assessed. Measures of detergent fiber, lignin, and digestibility were highly correlated with ethanol production (P < 0.01). The best linear regression models accounted for about 80% of the variation among cultivars in ethanol production. Bagasse from the cultivar Dale produced more ethanol per gram of material than any of the other cultivars. This superior ethanol production was apparently associated with less lignin in stems of Dale. Forage evaluation measures including detergent fiber analyses, in vitro digestibility, and an in vitro gas production technique successfully identified the cultivar superior in ethanol yield indicating their usefulness for screening sweet sorghum samples for potential ethanol production in research programs generating large sample numbers from evaluations of germ plasm or agronomic treatments. These screening procedures reduce time and expense of alternatives such as hexose sugar assessment for calculating theoretical ethanol yield.

Sweet sorghum is one of the most attractive feedstocks for producing liquid fuels in the world since it is well adapted to the various land conditions and efficiently converts CO2 into sugars. Sweet sorghum was evaluated as a raw substrate for production of ethanol from the whole plant. It consists of 37% juice, 8% seed head, 36% bagasse, and 19% leaf matter which can produce ethanol via fermentation of Saccharomyces cerevisiae. Especially, starch in seeds was hydrolyzed to simple sugars by amylase. Bagasse and leaf matter were treated with calcium hydroxide at 121°C for 1 h at 15 psi before hydrolysis by cellulase. In this study, 1 ton of whole sweet sorghum contains 283 kg solid matter and 229.8 kg carbohydrates and produces 59 kg ethanol.

Sweet sorghum (Sorghum bicolor (L.) Moench) is currently recognized throughout the world as a highly promising biomass energy crop. Production systems and management practices for sweet sorghum have not been fully developed for the USA, although sporadic research efforts during recent decades have provided some insights into production of sweet sorghum primarily for fermentable sugar production. Field plot experiments were conducted at sites across Louisiana to assess biomass and sugar yield responses to N fertilizer, plant density, and selected cultivars. Although linear increases in stem biomass production and fermentable sugar yield were obtained with increasing N fertilizer rate under irrigated conditions, most of the increase was from the initial 45 kg N ha−1 increment. Nitrogen fertilization increased stem biomass production but not fermentable sugar yield in some non-irrigated environments. Increased plant density contributed to fermentable sugar yield only under growth-limiting conditions, particularly under limited soil moisture. Location effects indicate that sweet sorghum may not be suitable for some sub-optimal cropland and pasture environments in Louisiana. During the primary growing season, cultivar did not affect fermentable sugar yields, although Dale was consistently high in sugar concentration during this period. Nitrogen fertilizer increased fermentable sugar yields only when moisture was not limiting. Overall results indicate that in environments where soil moisture limits plant growth, sugar yield responses are likely from increased plant density and not from increased N fertilization.

Background Previous research indicates that bahiagrass may be successfully conserved as baleage, but nutritive value is typically low for lactating dairy cows. The purpose of this study was to determine the effect of adding modest amounts of alfalfa forage (22%), achieved by inter-seeding alfalfa into an existing bahiagrass pasture, on baleage nutritive value and lactation performance of Holstein cows. Forage treatments employed were monoculture bahiagrass baleage (MBB; negative control), bahiagrass-alfalfa mixture baleage (BAB) and conventional corn silage (CCS; positive control). Thirty six mid lactation Holstein cows [34.8 ± 5.8 kg 3.5% fat-corrected milk and 112 ± 19 d in milk (DIM)] were stratified according to milk yield and DIM and assigned randomly to 1 of 3 forage treatments. Cows were trained to Calan feeding gates and were offered a common CCS-based TMR in a 10-d covariance period followed by a 42-d treatment feeding period. Results The BAB contained more protein and less NDF than MBB (12.6 vs 10.3% CP and 71.8 vs 76.6% NDF). Diet DMI was similar for MBB and BAB (19.5 vs 21.6 kg/hd/d), but cows consumed more of the CCS diet (25.5 kg/hd/d) than either baleage-based diet. Cows offered BAB tended to produce more milk than cows offered MBB based TMR (28.4 vs 26.1 kg/hd/d), but both baleage diets generated less milk than CCS-based diets (33.1 kg/hd/d). Milk composition was similar across diets except for milk protein concentrations which were higher for CCS than either MBB or BAB diets; however, milk urea nitrogen (MUN) was lowest for cows fed CCS diets. Cow BW gain was higher for BAB than MBB implying that a portion of the higher energy contributed by the alfalfa was being used to replenish weight on these mid lactation cows. Conclusions Data from this study indicate that alfalfa inter-seeded in bahiagrass sod that produces BAB with as little as 22% alfalfa may improve nutritive value compared to monoculture bahiagrass baleage and marginally improve lactation performance of Holstein cows. However, the CCS diet was vastly superior to either MBB or BAB-based diets for milk production.

Background Algae are widely recognized for their high oil content and for exponentially accumulating biomass with particular potential to provide single cell protein for human consumption or animal feed. It is believed that along with biodiesel from algae, the high protein de-oiled algal residue may become an alternative feed supplement option in the future. This study was conducted to investigate de-oiled algal residue obtained from the common Chlorella species, Thalassiosira weissflogii, Selenarstrum capricornutum, Scenedesmus sp., and Scenedesmus dimorphus for assessment as potential feed supplements for ruminants by comparing with soybean (Glycine max) meal and alfalfa (Medicago sativa) hay. Results With the exception of T. weissflogii, algal residue had higher concentrations of Cu, Zn, and Mn and lower concentration of Ca, Mg, and K than soybean meal and alfalfa hay. The algal residue CP (crude protein) concentrations ranged from 140 to 445 g/kg DM and varied among the de-oiled residues. In vitro rumen fermentation gas accumulation curves indicated that algal biomass degradation potential was less than that of soybean meal or alfalfa hay by up to 41.7%. The gas production curve, interpreted with a dual pool logistic model, confirmed that the fraction sizes for fast fermenting and slow fermenting of de-oiled algal residues were smaller than those in soybean meal and alfalfa hay, and the fermenting rate of the fractions was also low. Conclusions Inferior in vitro rumen gas accumulation from the five de-oiled algal residues suggests that these algal byproducts are less degradable in the rumen.