Grass Silage Research Articles

Enhancing Biogas Production of Co-Digested Cattle Manure with Grass Silage from a Local Farm in Landshut, Bavaria, through Chemical and Mechanical Pre-Treatment and Its Impact on Biogas Reactor Hydraulic Retention Time

Cattle manure usually contains a proportion of carbohydrates in the form of organic residues from incompletely digested feed and farm husbandry practices. These are not usually available for biogas production due to the long fermentation time. This paper investigates the optimal application of alkali, NaOH and KOH and mechanical pre-treatments to improve the degradation of the lignocellulosic content and the potential biogas yields from a local farm in Bavaria, Germany. Parameters such as temperature, pH, soluble chemical oxygen demand, organic acids, dry matter and volatile solids were analysed for this purpose. Alkali pre-treatments in 0.2, 0.1 and 0.05 M NaOH concentrations were tested in single mode and combined with shredding in batch experiments. The maximum increment of the soluble chemical oxygen demand during the pre-treatments took place during the first 50 h of experimentation, and it showed an improvement of 10,060.0 ± 8% mg/L s COD after the application of 0.2 M NaOH compared to the untreated substrate, which had an initial value of 2145.0 ± 8% mg/L s COD. Pre-treatments with 0.1 and 0.05 M NaOH concentrations showed similar s COD increments, with an additional 6860.0 ± 8% mg/L s COD and 8505.0 ± 8% mg/L s COD, respectively. The pH values varied strongly after the addition of the pre-treatment chemicals, with a continuous pH of 12 by 0.2 M NaOH during the 7 days of pre-treatment. Batch biogas experiments were done by applying 0.05 M NaOH and 0.05 M KOH pre-treatments in single mode and combined with shredding. The chemically pre-treated substrates showed a faster biogas production with an advantage of 18 days in comparison to the untreated cattle manure by a biogas yield of 350.0 NL/kg VS. All experiments were done under mesophilic conditions.

Effect of different dry matter content on fermentation characteristics and nutritional quality of Napier grass silage with novel lactic acid bacteria strains.

To investigate the characteristics of different LAB strains isolated from subtropics and their effects on Napier grass (Pennisetum purpureum Schum.) silage with two dry matter (DM) levels, sugar fermentation pattern, and growth profiles of three screened lactic acid bacteria (LAB) strains [Pediococcus pentosaceus (PP04), Weissella cibaria (WC10), and Lactobacillus plantarum (LP694)] were characterized, and then used either individually or in combination at 1.0×106 cfu g-1 fresh weight to inoculate grass having 15% or 25% DM. Treatments were applied: (1) no inoculant (control); (2) PP04; (3) WC10; (4) LP694; (5) M-1 (PP04: WC10=2:1); (6) M-2 (PP04: LP694=1:2); (7) M-3 (WC10: LP694=2:1); (8) M-4 (PP04: WC10: LP694=2:1:1). The results showed that all inoculations increased LAB, DM recovery, and lactic acid (LA) concentration, while decreasing pH, the ammonia nitrogen/total nitrogen (NH3-N/TN), and butyric acid (BA) concentration compared to control group in both DM. However, the effect of inoculations was very limited at 15% DM. Silages with inoculants achieved higher silage quality at 25% DM than 15% DM. The different LAB inoculants result in significant differences in silage quality, while W. cibaria decreased the pH and inhibited the growth of undesirable bacteria and those characteristics were not affected by the DM content.

Fermentation losses and aerobic stability of elephant grass silages containing Parkia platycephala pod meal and urea

Fermentation losses and aerobic stability of elephant grass silages with inclusion of 4 levels of Parkia platycephala pod meal (PP) (0, 10, 20 and 30 %) and 2 levels of urea (0 and 1.5 %) on as-fed basis were evaluated. The silages were analyzed for gas and effluent losses, dry matter recovery (DMR), pH and aerobic stability (pH and temperature) to determine effects of interactions between levels of urea and PP on gas losses, dry matter recovery, temperature and pH of the silages. The combination of urea and PP increased gas losses and reduced the DMR. PP reduced effluent losses and urea increased aerobic stability of the silages. pH values decreased with inclusion of PP and increased with use of urea. Silages containing 20 and 30 % PP showed greater stability over time, especially when associated with urea. PP with urea were effective in reducing effluent losses, maintaining DMR and allowing higher aerobic stability, with stability rupture from 40 h with the inclusion of 20 % of PP in elephant grass silages.

Effects of graded levels of dietary chromium-yeast on rumen and blood metabolites, feed digestibility, and performance of goats

The study was conducted to determine the effect of dietary supplementation of Chromium-yeast minerals on consumption, feed digestibility, rumen and blood metabolites, Average Daily Gain (ADG) and body condition score (BCS). The research was conducted at Gunung Tugel Farm, Banyumas, Central Java, Indonesia. The material used was 24 male Jawarandu goats with an average initial weight of 25 ± 1.23 kg, individual cages, the feed given consisted of elephant grass silage and concentrate. The treatment feed contains chromium-yeast at levels of 0, 0.5, 1, and 1.5 mg/kg. The research method used was experimental using a completely randomized design. There were 4 treatments tested, namely T0 (70% concentrate + 30% elephant grass silage), T1 (70% concentrate + 30% elephant grass silage + 0.5 mg/kg chromium-yeast), T2 (70% concentrate + 30% elephant grass silage + 1 mg/kg chromium-yeast) and T3 (70% concentrate + 30% elephant grass silage + 1.5 mg/kg chromium-yeast). Each treatment was repeated 6 times so there were 24 trials. The further test used is polynomial orthogonal. The variables measured in this study were feed consumption, feed digestibility, rumen metabolite products, daily body weight gain and body condition score. The results of the analysis of variance showed that the treatment had a significant effect on dry matter and organic matter consumption, feed digestibility, rumen volatile fatty acids (VFA), ammonia nitrogen (NH3-N) and blood glucose 3 h post-feeding, chromium-yeast levels, and had a very significant effect on ADG and BCS. In conclusion, chromium-yeast supplementation was able to improve goat performance with optimal levels ranging from 1.04–1.36 mg/kg of feed.

Environmental impacts and animal performance of finishing bulls fed different silage-based total mixed rations

The objective of this study was to evaluate the effects of three different grass silage (GS) based diets on environmental impacts and animal performance of finishing bulls. Experiment 1 (Exp 1) was conducted using 53 Aberdeen angus (AA) and 52 Simmental (SI) beef bulls and experiment 2 (Exp 2) included 69 Holstein (HO) and 36 Nordic Red (NR) dairy bulls. The three experimental diets included three different proportions of concentrates and two different types of forages. Moderate concentrate diet (MC) included GS, barley grain and mineral-vitamin mixture in proportions of 600:385:15 on dry matter (DM) basis while the respective proportions on low concentrate diet (LC) were 850:135:15. No concentrate diet (NC) included GS, whole crop barley silage and mineral-vitamin mixture (685:300:15). The bulls were fed total mixed rations ad libitum. Environmental impacts of the dietary treatments were estimated using a gate-to-gate life cycle assessment approach with the following key impact categories; global warming potential (GWP), eutrophication, and acidification potential. In Exp 1 the carcass gain, carcass weight and carcass conformation of the SI bulls were 10, 8 and 23% higher, respectively, compared to the AA bulls (P < 0.001) but there was no difference in feed conversion (kg DM/kg carcass gain) between AA and SI. In Exp 2 the NR bulls had 12% better conformed carcasses compared to the HO bulls (P < 0.001) but the carcass gain of the HO bulls tended to be 4% higher (P = 0.06) compared to NR. There was no difference in feed conversion or carcass weight between HO and NR. In both experiments, LC and NC diets impaired growth performance, feed conversion and carcass conformation compared to MC. In Exp 1 the GWP was 19.1 kg CO2 eq/kg of produced beef during the experiment with MC, 20.7 kg with LC and 25.9 kg with NC. Eutrophic emissions were 17.1, 21.3 and 21.8 g PO4 eq/kg of produced beef and acidifying emissions 38.6, 49.9 and 53.7 AE eq/kg of produced beef, respectively for MC, LC, and NC treatments. In Exp 2 the GWP was 20.7, 21.7 and 26.3 CO2 eq/kg of produced beef, eutrophic emissions 16.4, 18.9 and 20,8 PO4 eq/kg of produced beef and acidifying emissions 39.4, 50.6 and 59.2 AE eq/kg of produced beef for MC, LC, and NC treatments, respectively. It can be concluded that impaired feed conversion in LC and NC diets led to the higher environmental impacts compared to MC.

Lipid Characteristics of the Muscle and Perirenal Fat in Young Tudanca Bulls Fed on Different Levels of Grass Silage.

Beef derived from grass-fed cattle is a specific quality criterion. The effect of grass silage intake on quality characteristics, i.e., fatty acids, fat-soluble vitamins, and lipid-derived volatile composition of intramuscular and perirenal fat from fattening bull weaners were studied. Visible (VIS) and near-infrared (NIR) spectra were also obtained from perirenal fat. Perirenal fat analysis was performed for feeding differentiation purposes. A total of 22 Tudanca breed 11-month-aged bulls were finished on three different diets: grass silage and a commercial concentrate ad libitum (GS-AC), grass silage ad libitum and the commercial concentrate restricted to half of the intake of the GS-AC group (GS-LC), and barley straw and concentrate ad libitum (Str-AC). Feeding had a significant effect (p &lt; 0.05) on γ-linolenic acid and the ratio n-6/n-3 fatty acids. Furthermore, β-carotene content was greater in beef from silage groups than in the Str-AC group. Feeding also affected the perirenal fat composition. Beef from silage-fed bulls and straw-fed bulls could be differentiated by fatty acid percentages, especially 18:0, t-18:1, and c9-18:1, β-carotene content, b* colour value, and carotenoid colour index. However, the VIS or NIR spectra data showed poor differentiating performance, and the volatile composition did not have appreciable differentiation power.

Characteristics of lactic acid bacteria, microbial community and fermentation dynamics of native grass silage prepared in Inner Mongolian Plateau.

To prepare high-quality silage, we studied the chemical composition, silage fermentation, characterization, and identification of lactic acid bacteria (LAB) associated with the silage fermentation of native grass on the Inner Mongolian Plateau. LAB were isolated from fresh native grass and their silage, and silages were prepared using a small-scale fermentation system with 2-3 cm length in plastic bags. The dominant species of native grasses used were Stipa baicalensis, Leymus chinensis, Cleistogenes squarrosa, Melissilus ruthenicus and Pulsatilla turczaninovii, which contained 47.83-59.43 % moisture, 55.12-67.74 % neutral detergent fiber (NDF), and 8.72-14.55 crude protein (CP), and these nutrients did not change greatly during ensiling. Good preservation with a relatively low pH (below 4.44) and high (p < 0.05) lactic acid content (>0.58) was obtained after ensiling. Based on the morphological and biochemical characteristics, these isolates were divided into 12 groups (A-L). All isolate strains were gram-positive and catalase-negative bacteria that produce lactic acid from glucose. Group A-K were cocci, while group L was rod-shaped. Group A-E formed D-lactic acid, but group H-K formed L-lactic acid, and other groups formed DL-lactic acid. Group A-E were heterofermentative, and Group F-L were homofermentative types of LAB. According to the 16S rRNA gene sequences analysis, strains were identified as genus Leuconostoc (A, B, and C), Weissellla (D, E), Pediococcus (F, G), Enterococcus (H, I, J and K), and Lactiplantibacillus (L). Enterococcus (E.) faecium (29.17%, percentage of total isolates) and Pediococcus (P.) acidilactici (18.75%) were the most frequently occurring dominant species. This study suggests that the native grasses contained abundant LAB species, and they can be used as good-quality silages in animal husbandry. In addition, the strains P. acidilactici and E. faecium were the most frequently isolated from native grass silages as dominant species which can be a potentially excellent inoculant for native grass silage.

Performance of Dairy Cows Offered Grass Silage Produced within Either a Three- or Four-Harvest System When Supplemented with Concentrates on a Feed-to-Yield Basis.

More frequent harvesting of grass swards provides an opportunity to improve the nutritive value of grass silage. This study investigated the effect of offering silages produced within either a three- (3H) or four-harvest (4H) system on dairy cow performance when concentrate supplements were offered according to the individual cow's milk yield (feed-to-yield). Cows (n = 80) were allocated to either 3H or 4H at calving and remained on experiment for 25 weeks. Within both treatments, cows were offered silage from each harvest consecutively in proportion to the dry matter (DM) yield for each harvest. Silage was offered as a mixed ration with concentrate added at a rate of 8 kg/cow/day. Additional concentrates were offered on a feed-to-yield basis. Herbage yields were reduced in the 4H system, but 4H silage contained higher metabolisable energy and crude protein content compared to 3H. Cows offered the 4H silage had greater silage DM intake, milk yield and milk protein content, while milk fat content was greater in cows offered 3H silages. In conclusion, increasing harvesting frequency from three to four harvests per year can improve silage feed value, silage intakes and milk yields when concentrates are offered on a feed-to-yield basis.

Feed Clusters According to In Situ and In Vitro Ruminal Crude Protein Degradation.

Effective degradation (ED) of crude protein (CP) was estimated in vitro at 0.02, 0.05 and 0.08 h-1 assumed ruminal passage rates for a total of 40 feedstuffs, for which in situ ED was available and used as reference degradation values. For this, the Streptomyces&amp;nbsp;griseus protease test was used. The differences between in vitro CP degradation and the in situ CP degradation values were lowest in legume grains and highest in cereal by-products and barley. The differences between in situ and in vitro ED were expressed using a degradation quotient (degQ), where degQ = (EDin vitro - EDin situ)/EDin situ. Among the tested feedstuffs, eight specific clusters were identified according to degQ for the assumed passage rates. The feedstuffs clustered in an unspecific way, i.e., feedstuffs of different nutrient composition, origin or treatment did not necessarily group together. Formaldehyde-treated rapeseed meal, soybean meal, wheat, a treated lupin, sunflower meal and barley could not be assigned to any of the clusters. Groupwise degradation (range of degQ for assumed passage rates are given in brackets) was detected in grass silages (-0.17, -0.11), cereal by-products together with sugar beet pulp (-0.47, -0.35) and partly in legume grains (-0.14, 0.14). The clustering probably based on different specific nutrient composition and matrix effects that influence the solubility of feed protein and limit the performance of the protease. The matrix can be affected by treatment (chemically, thermally or mechanically), changing the chemical and physical structure of the protein within the plant. The S. griseus protease test had reliable sensitivity to reflect differences between native feedstuffs and treatments (thermally or chemically) that were found in situ. The in situ results, however, are mostly underestimated. The clustering results do not allow a clear conclusion on the groupwise or feed-specific use of carbohydrate-degrading enzymes as pre- or co-inoculants as part of the S. griseus protease test and need to be tested for its potential to make this test more conform with in situ data.

Sensory and chemical evaluation of laboratory ensiled hybrid Napier grass prepared using Lactobacillus plantarum and propionic acid as additives

The present study was undertaken to evaluate silage made from hybrid Napier grass (Pennisetum purpureum) ensiled in the laboratory using various additives with regard to sensory as well as chemical characteristics. Four different silages were prepared viz., grass ensiled without additives (GS) as control, and grass silage with Lactobacillus plantarum at 1 x 105 CFU per gram of fresh forage (GSL), grass silage with propionic acid at the rate 0.45 kg per ton of fodder (GSA), and grass silage with combination of Lactobacillus plantarum (1 x 105 CFU per gram of fresh forage) and propionic acid (0.45 kg per ton of fodder) (GSLA) in triplicates. One from each triplicate was opened on 21, 30 and 45 days of ensiling and was evaluated for sensory (colour, aroma, presence or absence of extraneous matter) and chemical (pH, lactic acid, proximate analysis and fibre fractions) characteristics. From the overall results, it could be concluded that hybrid Napier grass, ensiled for 21 days using L. plantarum was effective in preserving its nutritive value.

Associative effects of a mixed Brachiaria decumbens and Pennisetum purpureum grass feed on the ensiling properties

This study aimed to evaluate the effects of the association between two tropical grasses, Signal grass (Brachiaria decumbens) and Napier grass (Pennisetum purpureum) on the proximate composition, in vitro digestibility, and fermentation characteristics of ensiled material. A complete randomized design was used on three treatments namely Signal grass, Napier grass, and Signal-Napier grass combination. Silage was made using molasses applied in proportions of 1:2 with water and mixed with silage at the rate of 5% for a 5kg bag of 2.5cm cut grass. Signal-Napier grass combination silage was superior in almost all parameters to the two sole crop silages. After ensiling, a significant difference (p&lt;0.05) in most parameters was recorded. A significant difference (p=0.0004) in pH was determined where pH was lower in the sole Napier grass silage than that of the Signal-Napier combination and Signal grass. A similar outcome (P&lt;0.05) was recorded for crude protein, ash, ether extracts, nitrogen-free extracts, and neutral detergent fiber. However, no significant difference (p&gt;0.05) was obtained in dry matter (p=0.1524), crude fiber (p=0.5924), and ADF (p=0.1168). Although having poor digestibility values in all treatments, Signal grass proved to be better than the rest. Organoleptic characteristics were promising, with normal color, smell, and texture changes observed. These results indicated that the association of grasses had an impressive positive effect on the nutritional value and quality of silages. Therefore, the use of mixed grass silages is encouraged.

Óleo essencial nanoformulado de alecrim pimenta (Lippia sidoides) como aditivo em silagens consorciadas

Abstract The presence of spoilage microorganisms in forage interferes with the fermentation process of silage, due to competition with lactic acid bacteria for substrate, generating losses and influencing the nutritional value of the ensiled material. Thus, the objective is to evaluate the effect of “Alecrim Pimenta” essential oil (Lippia sidoides) and nanoformulated thymol on microbiological, fermentative and aerobic stability profile of sorghum (Sorghum bicolor cv. BRS Ponta Negra) silage intercropped with Paiaguás grass (Urochloa brizantha cv. BRS Paiaguás). A 4 x 3 factorial design was adopted, with four additives applied to the silages (control treatment; nanoformulated "Alecrim Pimenta" essential oil (OEN); 62% nanoformulated thymol; and 100% pure nanoformulated thymol), associated with three silo period times (15, 30 and 45 days), with five replications per treatment, totaling 60 mini silos. The Clostridium population was higher in the control treatment and in the OEN. The Lactobacillus population decreased with the increase in silo opening time. Higher aerobic stabilities were recorded in silages with 100% nanoformulated thymol with opening at 15 days; and silages with 62% nanoformulated Thymol (opening period at 30 and 45 days). Silages with 100% thymol provided higher losses of dry matter, gases and effluents, while the use of OEN provided lower losses of dry matter and gases. Silos opened at 45 days showed higher losses of dry matter, gases and effluents. Sorghum and Paiaguás grass silages that received nanoformulated thymol were more efficient in controlling Clostridium and Lactobacillus populations, and this additive improved the aerobic stability of the silage.

Fermentation characteristics and microbial counts of Megathyrsus maximus silage as influenced by Moringa oleifera seeds and ensiling period

Abstract The fermentation characteristics and microbial counts of Megathyrsus maximus ensiled at varying inclusions of Moringa oleifera seeds at different ensiling periods were investigated. Factorial experiment consisting of 3 varying proportions of grass and seeds (100:0, 75:25, and 50:50) and 4 ensiling duration (30, 60, 90, and 120 days) was carried out. The pH was significantly highest (p &lt; 0.05) with the highest inclusion of seeds while pH decreased with increased ensiling duration. Colour and odour changed as the level of seed inclusion increased in the silage while the moisture content (9.10) was significantly higher (p &lt; 0.05) at 30 days of ensiling. Ammonia nitrogen was highest at the highest level of seed inclusion while lactic acid was highest at 60 days of ensiling. Crude protein and tannin contents of the silage increased (p &lt; 0.05) following the increased seed inclusion while there was a reduction as the ensiling duration increased. The total anaerobic bacteria count, total lactobacilli count, and total yeast count of the silage decreased following the increased inclusion of seeds in the silage. As the ensiling duration increased, a reduction in all the silage microbial counts was observed. Inclusion of 25 % of the seeds to 75 % of the grass for silage with ensiling up to 120 days supported improved fermentation characteristics, microbial and crude protein contents as well as a reduction in tannin content which implies that there will not be a detrimental effect on animals that feed on the silage.

Efficient Nitrogen Recovery from Agro-Energy Effluents for Cyanobacteria Cultivation (Spirulina)

The present study aimed to obtain an efficient liquid nitrogen fertilizer from the by-product of anaerobic digestion for its subsequent use in the production of cyanobacteria (Spirulina). A simple recovery technology was tested based on the stripping and acid absorption, modifying temperature (50 and 70 °C) and pH (10 and 12), of the ammonia nitrogen contained in the digestate produced in a large-scale plant treating livestock manure and grass silage. The results demonstrated how, at a relatively low temperature (50 °C), using sulfuric and citric acid solution, it is possible to recover nitrogen from a digestate in the form of ammonium sulfate and ammonium citrate with yields of 70% and 72.1% respectively. By carrying out Spirulina growth tests, promising results were obtained under semicontinuous production, with a maximum dry biomass daily productivity of 0.344 g L−1 day−1 with ammonium sulfate and 0.246 gDW L−1 day−1 with ammonium citrate. The results showed that nitrogen can be efficiently recovered on site by using the organic acid, digestate and waste heat from anaerobic digestion for Spirulina biomass production.

The effects of spring feeding strategy on pasture productivity, sward quality, and animal performance within intensive pasture-based dairy systems

The objective of this research was to evaluate how different feeding strategies based on various pasture availability (PA) treatments within intensive seasonal production systems affected pasture production and utilization, sward quality, and the milk production, body weight (BW), and body condition score (BCS) of dairy cows. The performance data were obtained from a 3-yr experiment conducted previously (2018-2020, inclusive). In total, records from 208 spring-calving dairy cows were available for analysis. The animals were randomly allocated to 1 of 3 PA grazing treatments in spring that varied in average pasture cover (measured as herbage mass available above 3.5 cm) that was established via different pasture management strategies in the previous autumn. Thus, the opening average pasture cover across all paddocks on February 1 was 1,100 kg of dry matter (DM)/ha for high pasture availability (HPA), 880 for medium pasture availability (MPA), and 650 for low pasture availability (LPA), respectively. The measurements were taken over an 8-wk period during the first grazing rotation in spring, commencing on February 16 (±2 d) and finishing when all paddocks were grazed once on April 12 (±5 d). Paddocks that were part of the HPA treatment showed the highest pregrazing herbage masses and pregrazing sward heights (1,645 kg of DM/ha and 8.2 cm, respectively) compared with MPA (1,412 kg of DM/ha and 7.5 cm, respectively) and LPA (1,170 kg of DM/ha and 6.9 cm, respectively). Owing to the differences in PA, daily herbage allowance was greatest for HPA (11.7 kg of DM/cow), intermediate for MPA (10.2 kg of DM/cow), and lowest for LPA (8.8 kg of DM/cow), with the remaining feed deficit composed of additional daily grass silage supplementation (0.8, 1.5, and 2.8 kg of DM/cow for HPA, MPA, and LPA, respectively), while the daily concentrate and daily total feed allowance were equal between treatments during spring (2.7 and 15.0 kg of DM/cow). Despite salient differences in fresh pasture used, complementing pasture intake with grass silage did not affect daily or cumulative milk, solids-corrected milk, fat, or protein yield or milk constituents. Similarly, BW and BCS were also unaffected by PA treatment. The results highlight the importance of high spring pasture utilization and grazing efficiency achievable with higher pregrazing herbage masses, which also allow larger animal intakes from grazed pasture as the cheapest feed source during spring. Moreover, targeting an adequate pasture supply at the commencement of calving increases the grazing days per hectare and lowers the requirement for supplementary feed on farm, particularly when facing increasing variability in climatic conditions.

An analysis of the social and private return to land use change from agriculture to renewable energy production in Ireland

Increased use of renewable energy is a major part of Ireland's plans to reduce greenhouse gas (GHG) emissions, lessen reliance on fossil fuels, and enable sustainable economic growth. Two forms of renewable energy interesting Irish policymakers are bioenergy and solar PV. To scale up these technologies, land will be required to grow bioenergy feedstocks and erect ground mount solar PV arrays. A micro, farm-based approach is utilised to generate private returns from renewable energy production, and agriculture, adjusted for the cost of GHGs. This considers both the cost to society of increasing GHG emissions and the benefit of reducing emissions.This paper compares income that could be derived from renewable energy production with average agricultural income from the main farm systems in Ireland. The private (market and subsidy) and social (GHG) return from substituting renewable energy sources for the existing agricultural land use on 1 ha is considered. We also use input-output modelling to generate output multipliers for renewable energy technologies: biogas, biomethane, short rotation coppice (SRC) willow, and solar PV.The results show that the market return from growing 1 ha of grass silage and SRC willow is less than for all the main farming systems. When the social value of the feedstock is considered by putting a monetary value on displaced GHG emissions, producing grass silage and willow biomass can provide a better return to farmers than cattle and sheep farming. Due to the high land rental amounts available to farmers from solar companies, the market and social return is higher for using land to erect solar PV than any of the main agricultural activities. Results from the output multiplier analysis show that biomethane production has the highest multiplier while solar PV has the lowest.

Supplementation with Sunflower/Fish Oil-Containing Concentrates in a Grass-Based Beef Production System: Influence on Fatty Acid Composition, Gene Expression, Lipid and Colour Stability and Sensory Characteristics of Longissimus Muscle.

Beef contains an array of conjugated linoleic acid (CLA) isomers for which positive effects have been reported in animal models of human disease. The objectives were to develop a CLA-enriched beef production system and to assess its quality. Sixty Spring-born heifers were housed in Autumn and offered unwilted grass silage and a barley/soyabean concentrate or wilted grass silage and a concentrate containing sunflower oil and fish oil. In May, both groups were offered either pasture for 22 weeks, restricted pasture and sunflower oil and fish oil for 22 weeks, or pasture for 11 weeks and restricted pasture and sunflower oil and fish oil for the final 11 weeks. The predominant CLA isomer in beef was cis9, trans11 representing on average, 80% total CLA. The modified winter diet followed by supplementation for 22 weeks resulted in beef that had a CLA concentration that was higher, at a comparable intramuscular fatty acid concentration, than previously reported. The lipid and colour stability (over 10 days in modified atmosphere packaging) and sensory characteristics were generally not negatively affected. There were minor effects on the expression of candidate genes involved in lipid metabolism. Consumption of this beef would make a substantial contribution to the quantity of CLA suggested to have a positive effect on consumer health.

Dynamics in fermentation quality, bacterial community, and metabolic profile during silage fermentation of late-harvested elephant grass.

The present study aimed to evaluate the effects of delayed harvest and storage length on fermentation products, bacterial community, and metabolic shifts of elephant grass silage. The late-harvested elephant grass (LG) was naturally fermented (NLG) for 1, 3, 7, 15, 30, and 60 days, respectively. After 60-day ensiling, NLG displayed homolactic fermentation with low pH value, butyric acid, and ammonia nitrogen concentrations, and high lactic acid concentration, and ratio of lactic acid to acetic acid. Pseudomonas, Sphingomonas, and Pantoea dominated the bacterial community in LG, but Lactobacillus, Lactococcus, and Pediococcus were the advantageous genera in a 3-day and 60-day NLG. The correlation heatmap revealed that Acetobacter was positively related to acetic acid, ethanol, ammonia nitrogen, and butyric acid concentrations. There were distinct differences in the KEGG (Kyoto Encyclopedia of Genes and Genomes) metabolic profiles of fresh and ensiled LG. Ensiling suppressed the metabolism of amino acid, vitamins, and energy, while promoted the metabolism of carbohydrate. The LG can be well-fermented without additives, but its low crude protein content should not be ignored when applied in agricultural practice. The ensiling process remarkably affected the fermentation quality, bacterial community, and metabolic profiles of NLG.

Removal of CO2 and H2S from biogas and enhanced compressed bio-methane gas production from swine manure and elephant grass

Anaerobic co-digestion of concentrated swine manure with elephant grass silage was used, and this study carried out in full-scale three continuously stirred tank reactors was operated at mesophilic temperature. The Biogas impurity removal procedure was enhanced by using a molecular sieve and activated carbon. Two molecular sieve tanks are used to absorb water from the biogas. An activated carbon tank (2 meters) was used to eliminate H2S to &lt; 1 ppm before entering the gas tank. In the form of compressed bio-methane gas (CBG), production was 14,400 m3/day (CH4 60-70%), and the amount of CBG was 9,600 m3/day 6.8 tons/day. The raw biogas containing CH4, CO2, and O2 are 68.8%, 29.7% and 0% with H2S 768 ppm. After the enhancement process, CBG having CH4, CO2, O2 are 89.35%, 10.05 0% and 0.02% with &lt; 0.01 ppm H2S. Therefore, after the purification process amount of CO2, H2S gas was considerably reduced and CH4 was improved by up to 90% by volume, and then the CBG was compressed to 250 bar tanks to the fuel for cars. Therefore, these results clearly demonstrate that the activated carbon method is feasible to process for the removal of CO2 and H2S from biogas in a large-scale plant.

Digestive and metabolic efficiency of energy and nitrogen during lactation and the dry period in dairy cows.

The objective of this study was to characterize total-tract nutrient digestibility, energy balance, and N balance in the critical dietary and metabolic transitions of the lactation cycle. Twelve dairy cows were housed in tiestalls from 10 wk before to 16 wk after parturition. After 2 wk of adaptation to the facility and diet, digestibility of organic matter (OM), neutral detergent fiber (NDF), starch, and N were measured, and energy and N balances determined at weekly intervals by total collection of feces, urine, and milk over 48 h. Cows were individually fed ad libitum a grass silage- and corn silage-based total mixed ration during lactation and a corn silage- and barley straw-based total mixed ration during the dry period. Effects of stage of lactation were evaluated by clustering week in 5 groups: late lactation (wk -8 to -7), dry period (wk -6 to -1), and 3 early lactation periods (wk 1 to 5, wk 6 to 10, and wk 11 to 16). In lactation, apparent total-tract digestibility of OM, NDF, and starch was lowest in the first 5 wk of lactation. From wk 2 to 16 after parturition, apparent nutrient digestibility of all nutrients increased linearly, but with a negative quadratic component for dry matter, OM, and NDF, to levels comparable to those reported in last 2 wk of the previous lactation. However, differences in digestibility across lactation stage were moderate, illustrated by the difference between OM digestibility in late lactation (last 2 wk, 74.8%) and early lactation (first 5 wk, 72.5%). Cows were in negative energy balance for the first 8 wk after calving, and in negative N balance for the first 4 wk after calving. Based on energy and N balance, we predicted that 36.5 kg of body fat and 3.5 kg of body protein were gained in the last 8 wk before calving, and that 47.5 kg of body fat and 7.6 kg of body protein were mobilized in the first weeks of lactation. These predicted changes in body mass, both the gain before calving and loss after calving, were greater by 37% and 10%, respectively, than fluctuations in measured body weight (corrected for predicted gut fill and fetus weights). At wk 1 and 2 postpartum, body N loss corresponded to 25 and 29%, respectively, of total N excretion in milk, and body energy loss corresponded to 64% and 44%, respectively, of the energy exported to milk, illustrating the important contribution of N and energy from body stores to milk production in early lactation. Metabolic N efficiency, measured as total N output (milk and body) over digestible N input (from diet and body), averaged 54.4% in the last 2 wk of lactation, increased to 65.9% 2 wk after calving, and decreased linearly as lactation advanced to 61.9% by wk 16. Short (48 h) but weekly repetition of total collection of feces and urine appears to be a suitable approach to evaluate temporal changes in nutrient digestibility, energy balance, and N balance across lactation and the dry period.