Studies on the fermentation of chopped sugarcane

The fermentation of freshly harvested and chopped sugarcane (whole plant) was studied using laboratory silos (600 g capacity). The fermentation was accompanied by a rapid drop in pH during the first 24 h. After a storage period of ten days the fermented sugarcane (canelage) contained less than 10% of the original water-soluble carbohydrates (WSC), approximately 9% ethanol (dry weight basis) and 44% more acid detergent fibre (ADF) than did the original sugarcane. Sugarcane (whole plant) that had been allowed to lie in the field for 48 h before chopping and ensilage, contained 37% less WSC than did the fresh cane; the composition of the canelage (ten-day fermentation) prepared from this “wilted” sugarcane was similar to that prepared from freshly harvested sugarcane. Canelage (pH 3.49) prepared (53 days storage) in a commercial, horizontal silo contained (dry weight basis) 0.80% ethanol, 7.29% WSC, 2.68% crude protein, 1.15% acetic acid, 1.60% lactic acid and 42.4% ADF.     

Fermentation patterns of forage sorghum ensiled under different environmental conditions

The effects of temperature, aerobic and anaerobic conditions in the silo and plant characteristics [water-soluble carbohydrate (WSC) contents, growing season] on the fermentation characteristics of a tropical forage species, Sorghum bicolor cv. sugar-drip, were investigated. Silages fermented in oxygen-impermeable bags were well preserved and had low pH (3.7), high lactic acid [72 g kg^–1 dry matter (DM) 80% of total acids], and low butyric acid (0.12 g kg^–1 DM) and ammonia nitrogen (NH₃–N) (57 g kg^–1 total nitrogen contents. Conversely, the use of oxygen-permeable bags as silos allowed aerobic decomposition of the ensiled forages. Increasing the incubation temperature lowered the population of lactic acid bacteria, reduced lactic acid production and caused the pH to rise. The heterofermentative Leuconostoc spp. predominated on fresh forages but homofermentative Lactobacillus plantarum began to dominate after 5 and 8 days of fermentation. Heterofermentative lactobacilli, notably Lactobacillus brevis, were dominant among the isolates obtained from 100-day silages. Varying the WSC contents, by crushing and/or chopping the forage, and growing season did not significantly affect the fermentation quality of the resulting silages. It was concluded that the maintenance of anaerobic conditions is essential if good quality silage is to be produced from tropical forage species.     

赤红壤植蔗坡地坡面径流及溶解态氮磷流失特征

为探究南方高强度、高频次降雨下赤红壤区坡耕地土壤侵蚀及氮磷养分流失的特征,基于野外径流小区原位观测试验,通过测定自然降雨下赤红壤植蔗坡地坡面径流和溶解态氮磷流失量,探讨自然降雨下甘蔗种植对赤红壤坡面径流及溶解态氮磷流失的影响。结果表明：(1)2019年和2020年,径流量分别为1111.3 m~3/hm~2和3269.4 m~3/hm~2,硝态氮(NO~-₃-N)流失量分别为1.39 kg/hm~2和15.60 kg/hm~2,铵态氮(NH~+₄-N)流失量分别为0.37 kg/hm~2和1.02 kg/hm~2,可溶性磷流失量分别为0.20 kg/hm~2和0.27 kg/hm~2。2019年和2020年植蔗坡地径流及溶解态氮磷流失量均集中在6月份,占流失总量的45%以上,硝态氮(NO~-₃-N)是径流氮素流失的主要形式,占79%以上。此外,2019年和2020年5月至8月,侵蚀性降雨场次分别为18次和23次,侵蚀性降雨量分别为407.8 mm和668.0 mm。(2)不同侵蚀性降雨条件下,植蔗坡地溶解态氮磷流失量及其...     

Lactic acid fermentation of food waste for swine feed

This study was conducted to determine the effects of lactic acid bacteria (LAB, Lactobacillus salivarius) inoculation on the microbial, physical and chemical properties of food waste mixture (FWM) stored at ambient temperature (25 degrees C) for 10 and 30 days. A complete pig diet including restaurant food waste, bakery by-product, barley and wheat bran, and broiler poultry litter was amended with LAB at the levels of 0.1%, 0.2%, 0.5% and 1.0% and fermented anaerobically. These treatments were compared with intact FWM before storage and non-anaerobically stored FWM. Non-anaerobic storage of FWM showed microbial putrefaction with the loss (P < 0.05) of water and water soluble carbohydrate (WSC) and increases (P < 0.005) in protein and fiber. Anaerobic fermentation of FWM with or without LAB seemed effective in both 10- and 30-day-storage. The addition of LAB inoculants to FWM showed a linear trend (P < 0.05) toward an increase in the number of total and lactic acid bacteria and toward the nutritional improvement with WSC increased and fiber decreased. Long-term (30 days) storage resulted in consistent reduction (P < 0.05) in numbers of total and lactic acid bacteria and pH and showed little change in chemical components, compared with short-term (10 days) storage. On the basis of these results, LAB inoculation improved fermentative characteristics of FWM. Among anaerobic treatments, further WSC increase and NDF reduction did not occur (P > 0.05) when LAB-added levels were over 0.2%. Based on these observations the optimum level of LAB addition to FWM was 0.2%.     

Effect of level of fibre on performance and digestion traits in growing rabbits

An experiment was conducted to determine the effects of level of fibre on production performance, gastrointestinal tract development, caecum fermentation and fibrolytic activity in weaner to 2-month-old New Zealand rabbits. One hundred weaner rabbits were allocated in individual cages for five treatments in which they were fed each diet with ADF at 130 (NDF, 274.1; ADL, 39.7; CP, 158.4; EE, 26.8; starch, 252.5 g/kg), 160 (NDF, 292.9; ADL, 41.9; CP, 160.3; EE, 25.6; starch, 249.4 g/kg), 190 (NDF, 312.4; ADL, 50.5; CP, 157.6; EE, 24.2; starch, 218.2 g/kg), 220 (NDF, 343.9; ADL, 51.2; CP, 158.5; EE, 22.2; starch, 217.6 g/kg), and 250 g/kg (NDF, 375.7; ADL, 66.0; CP, 156.9; EE, 22.4; starch, 220.8 g/kg) original matter basis, respectively. The results were: ADG and F/G deteriorated with increasing fibre (P<0.05); ADI increased with increasing dietary ADF (P=0.002). The stomach relative weight (g/kg LW), small intestine relative weight (g/kg LW), caecum weight, caecum content weight and caecum relative weight (g/kg LW) all increased with increasing ADF (P=0.003, 0.007, 0.002, 0.010 and <0.001, respectively). Quadratic effects of level of ADF on the villus height, villus height/crypt depth of the duodenum and the villus height/crypt depth of the jejunum were obtained; cubic effects of level of ADF on the crypt depth of the jejunum and the villus height/crypt depth of the ileum were obtained. Cubic effects of level of ADF on the pH, the butyric acid (% total VFA) and C2/C4 were obtained. The NH₃–N concentration dropped and the acetic acid (% total VFA) increased when the dietary ADF increased (P<0.001). The fibrolytic activity measured in the caecal contents increased when the dietary ADF increased (P<0.001). Providing a ration consisting mainly of clover meal, wheat straw and peanut hulls, the optimum dietary ADF content for weaner to 2-month-old growing meat rabbits was shown to be 190 g/kg feed.     

Ensilage characteristics of three tropical grasses as influenced by stage of growth and addition of molasses

When molasses was added during ensilage of three tropical grasses [hamil grass (Panicum maximum cv. Hamil), pangola grass (Digitaria decumbens) and setaria (Setaria sphacelata cv. Kazungula)] the final pH, concentration of fermentation acids (except lactic acid) and NH₃–N content were all similar after 100 days of incubation. Pangola grass silage had significantly higher lactic acid content (66 g/kg dry matter) than the other two. Adding either 4 or 8% (w/w) molasses reduced NH₃–N, volatile fatty acid content and pH but increased lactic acid content in the final silages. Numbers of lactic acid bacteria remained approximately constant during the course of the fermentation, although large differences were noted in the species composition of the populations. At the time of ensiling, only Pediococcus spp. and Leuconostoc spp. were detected. By 5 days, the homo-fermentative population, notably Lactobacillus plantarum, dominated (43%) and remained dominant. Hetero-fermentative rods were only detected in the 100-day silage, where they represented 29% of the strains isolated. Homo-fermenters were more abundant in pangola (60%) and setaria (47%) silages than hamil (27%) silages. Homo-fermenter populations were lowest in the 12-week forage. Molasses additions increased homo-fermenter populations. Pangola grass gave the best quality silage but, since the water-soluble carbohydrate content in the grasses was insufficient to promote a strong lactic fermentation, the addition of 20 to 30 kg molasses/tonne should achieve satisfactory preservation.M. Tjandraatmadja and B.W. Norton are with the Department of Agriculture, The University of Queensland, Queensland, 4072, Australia; I.C. Mac Rae is with the Department of Microbiology, The University of Queensland, Queensland, 4072, Australia.     

Studies on ammonia-treated straw. II. Fixation of ammonia in treated straw by spraying with acids

Ammonia-treated barley straw (NH₃ straw) was sprayed with either formic, acetic or phosphoric acid immediately after opening the stack in order to capture the excess ammonia. The amount of acid applied was estimated to neutralize 100% of the ammonia added to the straw (30 kg NH₃/t straw). After spraying with acid the straw was stored in plastic bags for about 8 weeks at room temperature (15–20° C). When bags of NH₃ straw treated with acids were opened, there was very little smell of ammonia whereas there was a very strong smell from the bag of NH₃ straw without acid added.The nitrogen content of the straw (g/100 g DM) was for untreated straw, 0.88, NH₃ straw without acid, 2.50, and NH₃ straw with added formic acid, 3.49, acetic acid, 3.81, and phosphoric acid, 2.27. The digestibility of organic matter determined in sheep was 47.3, 60.5, 59.0, 60.4 and 51.3 following the same order as above.It is concluded that spraying NH₃ straw with organic acids effectively reduces the loss of ammonia and increases the nitrogen content of the straw. Another advantage of this is that the air pollution with ammonia which may occur in the barn when the straw is not well aired is effectively prevented.Spraying with organic acids had no negative effect on the digestibility of the straw. The nitrogen supply and the digestibility of nitrogen in the animal seemed to be markedly improved.     

Effect of lime, dicyandiamide and soil water content on ammonia and nitrous oxide emissions following application of liquid hog manure to a marshland soil

The loss of nitrogen (N) from field-applied animal manure through ammonia (NH₃) volatilisation and nitrous oxide (N₂O) emission is of major environmental concern. Both lime and dicyandiamide (DCD) have been suggested as amendments that can mitigate N₂O emissions, but simultaneously increase the risk of NH₃ volatilisation. This study evaluated the impact of lime and DCD on NH₃ and N₂O emissions following application of liquid hog manure. Hydrated lime (Ca(OH)₂) was added to an acidic soil to achieve three pH levels (4.7, 6.3 and 7.4). Soil samples (100 g) were then placed in 500 ml screw-top Mason-jars and de-ionised water was added to bring the samples to 50, 70 and 90% water-filled pore space (WFPS). Slurry was applied at a rate equivalent to 116,000 l ha⁻¹, while DCD was applied at 30% of the NH₄-N rate applied. Jars were sealed and incubated at 21°C for 21 d. Ammonia volatilisation was quantified using boric acid traps, while N₂O gas concentration was analysed using gas chromatography. Dicyandiamide had no effect (P>0.05) on either NH₃ or N₂O emissions. Both NH₃ and N₂O emissions increased (P<0.05) as WFPS increased, with emissions ranging from 0.9 to 1.4 kg NH₃-N ha⁻¹ and 123 to 353 g N₂O-N ha⁻¹, respectively. Liming decreased (P<0.01) N₂O emissions from 547 to 46 g N₂O-N ha⁻¹, but increased (p<0.01) NH₃ volatilisation from 0.36 to 1.92 kg NH₃-N ha⁻¹. Results suggest that liming to a pH ≥6.3 can reduce N₂O emissions, however, this reduction will be accompanied by a substantial loss of NH₃. Section Editor: H. Lambers     

Anaerobic mixed‐culture fermentation of aqueous ammonia‐treated sugarcane bagasse in consolidated bioprocessing

The MixAlco process is an example of consolidated bioprocessing (CBP) in which anaerobic mixed‐culture fermentation biochemically converts any biodegradable feedstock into carboxylate salts. Downstream processing thermochemically transforms the resulting salts into mixed alcohol fuels or gasoline. To enhance digestibility, sugarcane bagasse was treated under mild conditions (55°C, 24 h, and 30% aqueous ammonia solution with a loading of 10 mL/g dry biomass). Using NH₄HCO₃ buffer, the feedstock (80% ammonia‐treated sugarcane bagasse/20% chicken manure) was anaerobically fermented by a mixed culture of marine microorganisms at 55°C. Four‐stage countercurrent fermentations were performed at various volatile solids loading rates (VSLRs) and liquid residence times (LRTs). The highest acid productivity (1.14 g/(L day)) occurred at a total acid concentration of 29.8 g/L. The highest conversion (65%) occurred at a total acid concentration of 27.6 g/L. The continuum particle distribution model (CPDM) predicted the experimental total acid concentrations and conversions within 4.98% and 10.41%, respectively. When using NH₄HCO₃ buffer, ammonia pretreatment is an attractive option. The CPDM “map” shows that both high volatile solid conversions (78.8%) and high acid concentrations (32.6 g/L) are possible with 300 g/(L liquid) substrate concentration, 30 days LRT, 2 g/(L day) solid loading rate and NH₄HCO₃ buffer. Biotechnol. Bioeng. 2010;106: 216–227. © 2010 Wiley Periodicals, Inc.     

Ensilage of tropical grasses mixed with legumes and molasses

The effects of adding two legumes, Gliricidia sepium and Leucaena leucocephala, cv. Cunningham, and molasses on the fermentation characteristics of silages made from two tropical grasses (Pangola grass, Digitaria decumbens, and Setaria sphacelata cv. Kazungula) were investigated. Pangola grass silages contained significantly higher contents of water-soluble carbohydrates and lactic acid than did setaria silages after 100 days fermentation, but there were no significant differences between the two silages in populations of lactic acid bacteria and contents of total N and NH₃–N. Addition of either species of legume had no significant effect on fermentation acids and NH₃–N contents, and numbers of lactic acid bacteria. Addition of both legumes reduced NH₃–N production in the silages by 59% after 5 days' fermentation. Numbers of lactic acid bacteria were not significantly affected by the different treatments. Enterococcus faecalis represented 60% of the lactic acid bacteria isolated from the treated herbages prior to ensiling. By 100 days of fermentation, only lactobacilli were isolated: 82% homo-fermenters and 18% hetero-fermenters. Lactobacillus mesenteroides subsp. dextranicum was found only in the silage supplemented with 33% (w/w) legume. It was concluded that the low quality of tropical grasses used as feeds for ruminants may be significantly improved by ensiling these grasses with small amounts of molasses and with high-protein tree leaves.M. Tjandraatmadja and B.W. Norton are with the Department of Agriculture. The University of Queensland, Queensland, 4072, Australia; I.C. Mac Rae is with the Department of Microbiology, The University of Queensland, Queensland, 4072, Australia.     

Effect of Methionine Sulfoximine on the Accumulation of Ammonia in C(3) and C(4) Leaves : The Relationship between NH(3) Accumulation and Photorespiratory Activity

Additions of methionine sulfoximine (MSX), an inhibitor of glutamine synthetase (GS), result in an increase in NH₃ in seedling leaves of C₃ (wheat [Triticum aestivum cv. Kolibri] and barley [Hordeum vulgare var Perth]) and C₄ (corn [Zea mays W6A × W182E] and sorghum [Sorghum Vulgare var MK300]) plants. NH₃ accumulation is higher in C₃ (about 17.8 micromoles per gram fresh weight per hour) than in C₄ (about 4.7 micromoles) leaves. Under ideal conditions, when photosynthesis is not yet inhibited by the accumulation of NH₃, the rate of NH₃ accumulation is about 16% of the apparent rate of photosynthesis. A maximum accumulation of NH₃ was elicited by 2.5 millimolar MSX and was essentially independent of the addition of NO₃⁻ during either the growth or experimental period. When O₂ levels in the air were reduced to 2%, MSX resulted in some accumulation of NH₃ (6.0 micromoles per gram fresh weight per hour). At these levels of NH₃, there was no significant inhibition of rates of CO₂ fixation. There was also a minor, but significant, accumulation of NH₃ in corn roots treated with MSX. Inhibitors of photorespiration (isonicotinic hydrazide, 70 millimolar; 2-pyridylhydroxymethanesulfonic acid, 20 millimolar) or transaminase reactions (aminooxyacetate, 1 millimolar) inhibited the accumulation of NH₃ in both C₃ and C₄ leaves. These results support the hypothesis that GS is important in the assimilation of NH₃ in leaves and that the glycine-serine conversion is a major source of that NH₃.     

Efficacy of β-mannanase supplementation to corn–soya bean meal-based diets on growth performance,nutrient digestibility,blood urea nitrogen,faecal coliform and lactic acid bacteria and faecal noxious gas emission in growing pigs

A study was conducted to determine the efficacy of β-mannanase supplementation to a diet based on corn and soya bean meal (SBM) on growth performance, nutrient digestibility, blood urea nitrogen (BUN), faecal coliforms and lactic acid bacteria, and noxious gas emission in growing pigs. A total of 140 pigs [(Landrace × Yorkshire) × Duroc; average body weight 25 ± 3 kg] were randomly allotted to a 2 × 2 factorial arrangement with dietary treatments consisting of hulled or dehulled SBM without or with supplementation of 400 U β-mannanase/kg. During the 6 weeks of experimental feeding, β-mannanase supplementation had no effect on body weight gain, feed intake and gain:feed (G:F) ratio. Compared with dehulled SBM, feeding hulled SBM caused an increased feed intake of pigs in the entire trial (p = 0.05). The G:F ratio was improved in pigs receiving dehulled SBM (p < 0.05). Dietary treatments did not influence the total tract digestibility of dry matter, nitrogen and gross energy. Enzyme supplementation reduced (p < 0.05) the population of faecal coliforms and tended to reduce the NH₃ concentration after 24 h of fermentation in a closed box containing faecal slurry. Feeding hulled SBM tended to reduce NH₃ emission on days 3 and 5 of fermentation. In conclusion, mannanase supplementation had no influence on growth performance and nutrient digestibility but showed a positive effect on reducing coliform population and tended to reduce NH₃ emission. Dehulled SBM increased G:F ratio and hulled SBM tended to reduce NH₃ emission.     

Survival of <Emphasis Type="Italic">Listeria monocytogenes</Emphasis> in Wilted and Additive-Treated Grass Silage

Grass was field-dried to 3 different dry matter (DM) levels (200, 430 and 540 g/kg) and inoculated with 10⁶–10⁷ cfu/g of a Listeria monocytogenes strain sharing a phagovar occasionally involved in food-borne outbreaks of listeriosis. Formic acid (3 ml/kg) or lactic acid bacteria (8·10⁵/g) with cellulolytic enzymes were applied only to forages with low and intermediate DM levels. Forages were ensiled in laboratory silos (1700 ml) and were stored at 25°C for 30 or 90 days. After 90 days of storage, L. monocytogenes could not be detected in any silo, except one with the high dry matter grass without additive. After 30 days of storage, between 10² and 10⁶ cfu L. monocytogenes/g silage were isolated from the untreated silages. Increasing the DM content from 200 to 540 g/kg did not reduce listeria counts possibly because of the lower production of fermentation acids (higher pH). In silages treated with additives, counts of L. monocytogenes were always lower than in silages without additive. In wet silages (DM 200 g/kg) both additives were effective, but in the wilted silages (DM 430 g/kg) only the bacterial additive reduced listeria counts below detection level. Listeria counts were highly correlated to silage pH (r = 0.92), the concentration of lactic acid (r = -0.80) and the pooled amount of undissociated acids (r = -0.83).     

Effects of urea and aqueous ammonia treatment on the composition and nutritive value of maize residues

Two trials were conducted to investigate changes in chemical composition and nutritive value of maize residues treated with urea and aqueous ammonia. In Experiment I, maize stalks, husks and cobs were chopped into pieces of approximately 1 cm length. Aqueous NH₃ (3%) and feed grade urea equivalent to 3% NH₃ were sprayed into 100 g duplicate samples on DM basis, thoroughly mixed, stored in plastic containers and kept for 3 week at ambient temperature (25–27 °C). Proximate composition and in vitro dry matter digestibility of test materials were determined. In Experiment II, 100 kg batches of the maize residues were chopped and treated as in Experiment I but stored in 205 l drums lined with black polythene sheet. Feed intake and nutrient digestibility of treated materials were evaluated with 18 mature WAD sheep averaging 19.8 kg BW. Treatment improved (P < 0.05) intake and digestion coefficients for N, DM, NDF, ADF and OM but there were no differences (P > 0.05) between aqueous NH₃ and urea treatments. Feed grade urea or the equivalent weight of fertilizer grade urea can be used to improve the nutritional value of maize residues for small ruminant feeding during off season periods.     

Improving live weight gain of crossbred Limousin bulls with cassava peel silage

There is a growing demand for beef products across developing countries. Formulating rations to include locally available waste products has the potential to increase the live weight gain (LWG) of cattle and improve the livelihoods of smallholder farmers; however, upper limit inclusion levels of cassava peel products require investigation. An experiment evaluated the effect of using cassava peel silage (CPS) at the DM inclusion levels of 30, 40, 50, 60 and 70% (with the remainder protein meals and maize stover in the diet) on the LWG of crossbred Limousin × Ongole bulls (269 ± 48.8 kg). Thirty bulls, approximately two years of age, were allocated in a completely randomised block design with six blocks based on initial live weight (LW) and five treatments based on level of CPS. The combination of CPS (with 2% urea of the CPS) and protein meals significantly affected LWG with the highest values obtained at levels of 30 and 50% inclusion of CPS (1.16–1.35 kg/day) (P < 0.05). Polynomial analysis of LWG data revealed the optimal LWG is theoretically achieved at 37% CPS with a LWG of 1.31 kg/day; however, LWG was similar from 30 to 50% inclusion levels and then declined. There was little significant difference at CPS inclusion levels of 30–60%, for DM intake (DMI) which ranged from 2.3 to 2.6% LW, organic matter (OM) digestibility (77.8–81.6%), feed conversion ratio (FCR) (6.56–7.56 kg DM/kg LWG) and feed cost of gain (Indonesia rupiah (IDR)/kg LW 18 612 – 21 398). At a high (70%) level of CPS inclusion, these values were markedly changed when compared to the 30% inclusion level of CPS. Feed treatments did not affect rumen pH, NH₃-N, concentration or molar percentage of volatile fatty acids or protozoal population (P < 0.05). Rumen pH measured three hours after morning feed ranged from 6.7 to 6.8 and NH₃-N ranged from 14.1 to 19.3 mg NH₃-N/dl. It was concluded that inclusion of CPS up to 60% mixed with protein meals and urea and 20% maize stover maximised LWG and profitability of the production system.     

玉米自交系秸秆品质性状鉴定与评价

利用近红外漫反射光谱法,对50份常用普通玉米自交系和50份高油自交系秸秆的中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)、可溶性糖(WSC)和粗蛋白(CP)4个品质性状进行了鉴定评价和相关性分析。结果表明,各品质性状变异较大,各性状自交系间差异均达极显著水平。不同品质性状变异程度不同,其中WSC含量变异最大,变异系数达34.23%。WSC与NDF、ADF极显著负相关,NDF与ADF含量极显著正相关。高油系表现为高WSC、CP和低NDF、ADF含量,总体上高油系秸秆品质优于普通玉米。     

The influence of ammonia on the growth and photosynthesis of Ruppia drepanensis Tineo from Doñana National Park (SW Spain)

In a laboratory experiment, Ruppia drepanensis Tineo seedlings from a brackish marsh in Southern Spain were grown at 20 and 30 °C, at three different nitrogen levels. These levels were obtained by the addition of a slow release fertilizer (23% NH₄NO₃ by weight) to a sediment mixture of sand and clay (3:1). Several morphometric parameters were recorded during the first five weeks of the experiment, and photosynthesis and respiration were measured after 7 weeks of growth. Results showed a significant reduction of growth and development with increasing nitrogen and temperature levels. Dark respiration increased strongly at high nitrogen levels. At the same time, net photosynthesis at 250 and 500 µE m^-2 s^-1, Pm, Km and LCP were not affected by either factor. We attribute these phenomena to ammonia toxicity, since relatively high total ammonia (NH₃ + NH_f4 ^p+) levels were found in the interstitial water.     

Gaseous nitrogen losses and ammonia volatilization measurement following land application of cattle slurry in the mid-Atlantic region of the USA

To provide locally-determined field data for extension and environmental management purposes, gaseous N losses were measured following cattle slurry application to an arable silty-loam soil in the mid-Atlantic region of the USA. The field had been cropped to no-till maize. NH₃ volatilization was measured with the micro-meteorological, integrated horizontal flux (IHF) method, and denitrification with a core incubation method using acetylene inhibition. An early-winter surface application (5 December 1996; 88 m³ ha⁻¹ supplying 91 kg NH ₄ ⁺ -N ha⁻¹) was either unincorporated or immediately incorporated. NH₃ volatilization was measured from the unincorporated application, and denitrification from both slurry treatments and appropriate control soils. Total NH₃ loss from the unincorporated slurry application was 19% of applied NH ₄ ⁺ -N; temperatures were cool (4–6 °C), and 25 mm of rain fell within 24 h of application. For 3 months, enhanced denitrification occurred from the two slurry treatments, with generally higher rates from the incorporated slurry. Total net denitrification loss from the surface-applied and incorporated slurry treatments was, respectively, 11 and 17% of applied NH ₄ ⁺ -N. Denitrification loss over the winter/early-spring period was appreciable but not substantial, even where NH₃ volatilization was restricted by immediate incorporation. From the spring application (30 April 1997, 39 m³ ha⁻¹ supplying 51 kg NH ₄ ⁺ -N ha⁻¹), total NH₃ loss was 71% of applied NH ₄ ⁺ -N. These NH₃ volatilization loss data and the similarity of climate suggest that NH₃ loss factors from recent NW European work are likely to be generally applicable in the mid-Atlantic region. NH₃ volatilization from the spring application was also measured using the Z-instrument (Z_INST) approach, and with a system of small wind tunnels. A comparative assessment of the three methods is reported.     

Predictors of Weight Loss in Adults with Topiramate‐Treated Epilepsy

Objective: We examined predictors of weight loss with topiramate, an anticonvulsant associated with weight loss in adults. Research Methods and Procedures: In this uncontrolled, prospective clinical trial, topiramate was added to existing anticonvulsants in adults (40 to 110 kg) with partial‐onset seizures. Primary measurements were change from baseline weight after 3 months and 1 year in patients completing 1 year of topiramate treatment (N = 38). Physiological and metabolic measures were analyzed for correlation with weight loss during topiramate treatment. Results: In patients who completed 1 year of topiramate treatment, baseline weight was reduced in 82% at 3 months and in 86% at 1 year. Mean body weight was reduced 3.0 kg (3.9% of baseline) at 3 months and 5.9 kg (7.3%) at 1 year. In obese patients [body mass index (BMI) ≥ 30 kg/m²], mean weight loss was 4.2 kg (4.3%) at 3 months and 10.9 kg (11.0%) at 1 year. Weight loss was primarily caused by reduction in body fat mass. For all patients, weight loss at 3 months correlated most strongly with reduced caloric intake (p = 0.02). At 1 year, caloric intake had returned to baseline levels; weight loss correlated most strongly with higher baseline BMI (p = 0.0007). Discussion: Our results suggest that weight loss occurs in most adults treated with topiramate and is sustained for at least 1 year. Reduced caloric intake may account, in part, for weight loss during early treatment. The pattern of weight loss differs according to baseline BMI, with obese patients experiencing greater weight loss during continued therapy.     

Bacteriological and chemical changes occurring in Bunker-stored silage covered with biodegradable coating

AIMS: To evaluate the efficacy of a biodegradable silage coating for the ability to protect timothy (Phleum pratensa) type silage against spoilage and its quality under natural conditions. METHODS AND RESULTS: Triplicate mini-silos of silage were prepared for three treatments (1: uncoated; 2: coated with biodegradable coating and 3: sealed with plastic), two types of storage (unprotected or protected from rain) and 10 sampling times (0, 7, 14, 21, 28, 35, 42, 56, 63 and 70 days postensiling). Triplicate mini-silos were opened at each sampling time for microbiological (total aerobic bacteria, lactic acid bacteria, moulds and yeasts) and biochemical analyses [pH, dry matter (DM), water-soluble sugars (WSC), lactic (LA), acetic, propionic and butyric acids content]. The study showed that at day 70, counts of moulds and yeasts in silages protected against rain and coated with biodegradable coating were 5.98 log CFU g(-1) when compared with 5.92 and 3.62 log CFU g(-1) in samples from plastic-sealed silage and uncoated silage, respectively. The pH was low and stable pH (4.34) when compared with uncoated (7.17) and plastic sealed (8.34) silages (P < or = 0.05). A DM, WSC and LA content of 421.7, 13.4 and 20.9 g kg(-1) was, respectively, observed. For silage stored outdoors, a level of moulds and yeasts of 3.77 log CFU g(-1) of silage was also observed in silages coated with biodegradable coating after 28 days of storage. A stable pH showing a mean value of 4 was also observed. The pH, DM, WSC and LA content were, respectively, 4.18, 341.1, 13.34 and 31.8 g kg(-1) in these samples. After 70 days of storage, the level of moulds and yeasts on silage sealed with biodegradable coating was 7.73 log CFU g(-1). A DM, WSC and LA content of 291.9, 5.56 and 10.0 g kg(-1) was, respectively, observed. CONCLUSIONS: When compared with uncoated silage, the application of biodegradable coating can preserve the quality of silage for up to a month when exposed to rain and up to 70 days when protected from rain. SIGNIFICANCE AND IMPACT OF THE STUDY: Results emphasize the possibility of the use of a biodegradable coating as an alternative to plastic film for sealing horizontal bunker silos.