Matter Recovery Research Articles

Conservation characteristics and protein fractions of cereal silages ensiled with additives at the booting and dough stages of maturity

The experiment was conducted to investigate the effects of organic acid and bacterial inoculant on conservation characteristics and protein fractions as defined by the Cornell Net Carbohydrate and Protein System of barley, wheat, rye, triticale, and oat silages ensiled at their booting or dough stage of maturity. The cereal crops were not treated or were treated with bacteria (L. buchneri, L. plantarum, E. faecium) or organic acid (formic acid, propionic acid, sodium formate) and ensiled in 1.0-L anaerobic jars for 45 days. Bacterial inoculant improved the fermentation profile for all cereal silages and increased the dry matter (DM) recovery at both maturity stages. The benefit of bacteria inclusion in the silage was more pronounced when applied at dough stages. Organic acid also improved the fermentation profile for all cereal silages, but it was less effective than the bacteria at both booting and dough stages of maturity. The reduction (P < 0.001) in in vitro DM digestibility was not as sharp as the decrease in crude protein (CP). Protein A fraction and digestible CP were higher (P < 0.001) at the booting stage, while all B fractions and C fraction were higher (P < 0.001) in cereal silages ensiled at the dough stage. It was concluded that additives, in particular bacterial inoculant, can improve fermentation and protein quality at both stages examined.

Numerical modeling, calibration, and validation of an ultrasonic separator

Our overall goal is to apply acoustic separation technology for the recovery of valuable particulate matter from wastewater in industry. Such large-scale separator systems require detailed design and evaluation to optimize the system performance at the earliest stage possible. Numerical models can facilitate and accelerate the design of this application; therefore, a finite element (FE) model of an ultrasonic particle separator is a prerequisite. In our application, the particle separator consists of a glass resonator chamber with a piezoelectric transducer attached to the glass by means of epoxy adhesive. Separation occurs most efficiently when the system is operated at its main eigenfrequency. The goal of the paper is to calibrate and validate a model of a demonstrator ultrasonic separator, preserving known physical parameters and estimating the remaining unknown or less-certain parameters to allow extrapolation of the model beyond the measured system. A two-step approach was applied to obtain a validated model of the separator. The first step involved the calibration of the piezoelectric transducer. The second step, the subject of this paper, involves the calibration and validation of the entire separator using nonlinear optimization techniques. The results show that the approach lead to a fully calibrated 2-D model of the empty separator, which was validated with experiments on a filled separator chamber. The large sensitivity of the separator to small variations indicated that such a system should either be made and operated within tight specifications to obtain the required performance or the operation of the system should be adaptable to cope with a slightly off-spec system, requiring a feedback controller.

Acute transverse myelitis in demyelinating diseases among the Chinese

The aim of the study was to characterize the demographic, clinical, and prognostic features of Chinese patients with acute transverse myelitis (ATM). The clinical data from ATM patients in a demyelinating disease database were analyzed retrospectively. Sixty-seven ATM patients with a follow-up duration longer than 2 years were identified. The frequency of neuromyelitis optica-related ATM (NMO-ATM) was high in our cohort (40.3%). Recurrent ATM (R-ATM), with a female predominance, was common in total idiopathic ATM (69.0%, 20/29). In R-ATM with longitudinally extensive spinal cord lesions (LESCLs), the high seropositivity of NMO-IgG, spinal cord lesions mostly involved the central gray matter and severer long-term disability were similar to NMO-ATM. In RTM without LESCLs, low seropositivity of NMO-IgG, preferentially involvement of the peripheral white matter and relative better neurological recovery were consistent with multiple sclerosis-related ATM (MS-ATM). The transition rates to MS in patients with acute partial transverse myelitis (APTM) and acute complete transverse myelitis (ACTM) were not significant (16.7 vs. 6.3%, P = 0.753), while LESCLs (OR = 11.4, P = 0.028) were significantly correlated with transition to NMO. The presence of LESCLs was the only variable showing a higher risk for reaching Rankin 3 (hazard ratio: 2.5, 95% CI: 1.0-6.1). Chinese patients with ATM had demographic, clinical, and prognostic features different from those in Western populations. Idiopathic R-ATM, common in Chinese, is a heterogeneous entity that shares partial clinical, spinal MRI and prognostic features with MS-ATM and NMO-ATM. The length of spinal cord lesion, rather than APTM/ACTM, may be a prognostic factor associated with clinical outcome and long-term disability in our population.

Bromatological and microbiological characteristics of sugarcane silages treated with calcium oxide

It was evaluated the addition of calcium oxide (0; 0.5; 1.0; 1.5; and 2.0% of dry matter) effect on the chemical composition and ruminal degradability of the dry matter and neutral detergent fiber, on the losses of dry matter, and on the microbial population in sugar cane silages. A design with five levels of calcium oxide and three replications was used. All the variables were influenced by the addition of calcium oxide in the silages, except the composition in acid detergent insoluble protein, water soluble carbohydrates and lignin. The dry matter content and pH linearly increased while the contents of organic matter, hemicellulose and crude protein linearly decreased with the levels of calcium oxide. Neutral detergent fiber corrected for ashes and protein and acid detergent fiber were adjusted for the quadratic models with calculated minimal values of 33.3 and 22.5% for the levels 1.73 and 1.49% of calcium oxide, respectively. The in vitro digestibility of the dry matter and the content of amoniacal nitrogen adjusted to quadratic models with maximal levels of 80.1% and 9.1% for the levels of 1.8 and 0.7% of calcium oxide, respectively. The minimal production of gas (3.18%) was observed at the level of 1.39% of calcium oxide. Production of effluent and recovery of dry matter of the ensiled mass showed a reduction and a linear increase, respectively, with addition of calcium oxide. The highest lactic acid bacterial population was observed in the silage treated with 1.5% of calcium oxide. The addition of calcium oxide increased degradability of the soluble fraction of the dry matter, which was higher than 50% and reduced the non- degradable fraction of the neutral detergent fiber. Addition of calcium oxide level higher than 1.0% in the sugar cane during ensilage improves in vitro dry matter digestibility and the recovery of dry matter, increases populations of lactic acid bacteria and reduces production of yeasts.

English

Particulate organic matter (POM) and aggregate recovery following mining disturbances are important for soil biogeochemical properties and ecosystem function. The objective of this study was to track POM accumulation and aggregation in reclaimed soils following coal mining in southwestern Virginia. A chronosequence of sites was selected based on shifts in vegetation communities with succession, typically occurring between 0-2, 5-7, 16-20, and 38-42 years since reclamation. Undisturbed adjacent forested sites were also sampled. The 0-2 yr old sites were covered with grasses and forbs, the 5-7 yr sites by thick stands of Lespedeza cuneata, the 16-20 yr sites predominately with Festuca arundinaceae and patches of deciduous trees (Acer rubrum, Oydendrum arborea, etc.) and the 38-42 yr old sites with a mix of Pinus taeda and deciduous forest with a grass understory. Undisturbed sites predominantly supported mixed Appalachian deciduous forest. Available POM (inter-aggregate) and physically protected (intra-aggregate) forms were determined using a density flotation technique and aggregate size distribution with wet sieving. Inter-aggregate POM did not change across site ages; however, intra-aggregate POM increased significantly between the 5-7 and 16-20 yr old sites and remained unchanged through the 38-42 yr old reclaimed site. Inter-aggregate POM reached levels similar to undisturbed sites, while intra-aggregate POM weights were almost threefold that of undisturbed sites after 16-20 years. By observing just the available POM, we would conclude that reclaimed systems recover to an protected POM, reclaimed system POM storage greatly exceeded undisturbed soil conditions. A positive relationship was observed between small macroaggregates (250-2000 μm) and intra-aggregate POM, suggesting that protection of POM by small macroaggregates in reclaimed systems is extremely important for POM accumulation and subsequently ecosystem function within a period of 20 years. We can also argue the greatest rates of POM accumulation and aggregate formation occur under early succession communities with grasses and forbs rather than under late succession forested communities.

Comparative environmental analysis of waste brominated plastic thermal treatments

The aim of this research activity is to investigate the environmental impact of different thermal treatments of waste electric and electronic equipment (WEEE), applying a life cycle assessment methodology. Two scenarios were assessed, which both allow the recovery of bromine: (A) the co-combustion of WEEE and green waste in a municipal solid waste combustion plant, and (B) the staged-gasification of WEEE and combustion of produced syngas in gas turbines. Mass and energy balances on the two scenarios were set and the analysis of the life cycle inventory and the life cycle impact assessment were conducted. Two impact assessment methods (Ecoindicator 99 and Impact 2002+) were slightly modified and then used with both scenarios. The results showed that scenario B (staged-gasification) had a potentially smaller environmental impact than scenario A (co-combustion). In particular, the thermal treatment of staged-gasification was more energy efficient than co-combustion, and therefore scenario B performed better than scenario A, mainly in the impact categories of "fossil fuels" and "climate change". Moreover, the results showed that scenario B allows a higher recovery of bromine than scenario A; however, Br recovery leads to environmental benefits for both the scenarios. Finally the study demonstrates that WEEE thermal treatment for energy and matter recovery is an eco-efficient way to dispose of this kind of waste.

Utilidad del renograma diurético en la detección de una fístula enteroureteral

After a 2-year-old male with left impairment underwent surgery for a left vesicoureteral stenosis, his renal function was followed up by means of dynamic renal scintigraphy with 99mTc-DTPA. Incidental radiotracer accumulation was observed in left hemiabdomen tracing the descending and sigmoid colon. A vesico-colonic fistula was suspected. However, ultrasonography and cystography studies showed no presence of a vesico-enteric fistula. Because the patient persisted without symptoms, an expectant approach was adopted. One year later, he began to suffer watery diarrhoea episodes. 99mTc-DTPA renography was again performed to re-evaluated renal function and explore presence of urinary-enteric fistula. Diuretic renography demonstrated the presence of a vesical leak to sigmoid gut, which was confirmed by recovery of fecal matter from the patient. Both isotopic renograms evidenced the presence of uretero-sigmoid fistula, an uncommon postsurgical that was not detected by cystography, ultrasonography or RMN. The patient subsequently underwent surgery for fistula repair.

Treatment Performance of Membrane Bioreactor for Organic Acid Fermentation

This study focused on the treatment performance of membrane bioreactor (MBR) coupled with intermittent ozone bubbling for the effective recovery of dissolved organics from coagulated fresh sewage sludge. Intermittent ozone bubbling was effective in the prevention of permeation resistance increase caused by particle accumulation on membrane surface, which result in keeping high permeation flux. MBR with intermittent ozone bubbling is believed to be an effective system for the recovery of organic matter usefully utilized in biological denitrification as well as membrane fouling reduction.

Forages resources in "dehesa" system: fertilization, tillage and forage sowing. I. Influence to the environment (soil and vegetation)

This work studies the ecological impact to the environment (soil, vegetation) produced by the application of differenttreatments, such as phosphoric fertilization, superficial tillage on the pasture, or deep ploughing and sowing fodder, ontwo types of soil, slate and granite over the period 1994-1997. The evolution of the chemical and granulometric compositionof the soil and also the covering and floral composition of the vegetation was monitored. The duration of the residualeffect was also considered, in order to determine the best possible time to carry out these practices. The evolution ofthe pH and the levels of organic matter, carbon, nitrogen, calcium, phosphorus, potassium, clay, lime and humidity werethe main factors surveyed on the soil. For each type of treatment, the floral abundance and density of the vegetation wasrecorded and catalogued. One of the conclusions obtained was that both the content in organic matter of the soil and thefloral cover decreases with sowing of fodder. The recovery of the soil organic matter usually takes more than four years,whereas the vegetation cover reaches its initial levels after three years. By the end of the experimental period these coverlevels are even higher than the original ones. In three year old oat stubble, pastures that can be related to syntaxonomicunits (Koelerio Corynephoretea y Molinio-Arrhenateretea) were seen. The plots of fertilized pasture showed higher levelsof legumes whereas the plots that had been fertilized and ploughed showed increased values of both legumes and grasses.The oat stubble showed higher levels of Composites after the first year, but their presence decreased with time.

Optimization of conditions for myofibril preparation from mechanically recovered chicken meat.

The influence of various conditions affecting the isolation of a myofibrillar preparation (MP) from chicken mechanically recovered meat (MRM), i.e. the time of additional chopping in a bowel chopper, washing time, the number of washings, and the water to MRM ratio, on the recovery of dry matter and myofibrillar protein, and fat content in the preparation was investigated. The following particular steps were determined to be the most desirable parameters: chopping MRM for 10 minutes, washing time of 15 minutes, 3 (or 2) consecutive washings, 3:1 water to MRM ratio (v/w). Under these conditions a significant decrease of fat content (93% on average) was found in comparison to the content in MRM. The removal of fat, sarcoplasmic protein and connective tissue increased the concentration of myofibrillar protein. The number of aqueous washings of MRM had the biggest influence on the protein and fat content in the concentrate. Electrophoretic analysis (SDS-PAGE) of protein in the preparation obtained under optimal conditions showed that myosin heavy chains (MHC) and actin constituted approximately 50% of all the proteins in the preparation.

Effect of the availability of magnesium ions in κ-carrageenan gels on the formation of conidia by Coniothyrium minitans

An isolate of Coniothyrium minitans did not sporulate on media to which 0‐05 mm magnesium was added when j-carrageenan was used to solidify the medium. Normal conidiation was observed when a technical grade agar or agar-agar was used as the gelling agent. The j-carrageenan and agars used in this study contained significant amounts of Mg. In the agar media all the Mg present was available to the fungus. By contrast, in the j-carrageenan gel a large portion of the Mg was bound by the gel and not available. Sporulation of C. minitans was only observed on media containing & 0‐17 mm of unbound Mg. The possible role of Mg in the initiation of conidium formation by C. minitans is discussed. Most microbial cultivations in industry are done in submerged culture. For some processes, however, cultivation on solid substrates in the absence of free-flowing water (solid-substrate cultivation) is advantageous. The production of high quantities of Coniothyrium minitans W. A. Campb. conidia, for instance, in stirred-tank reactors has heretofore not been reported. Numerous conidia, however, can easily be obtained when C. minitans is grown on various solid substrates (McQuilken & Whipps, 1995). These conidia are a promising biocontrol agent to treat Sclerotinia sclerotiorum contaminated soils and plants (Whipps & Gerlagh, 1992). The prospects of a biocontrol agent based on C. minitans are promising, provided that an ecient production process is developed. Optimization of the solid substrate with respect to spore formation is essential for the development of a cost-eective biocontrol agent. Quantification of biomass dry weight is important in such optimization studies. Direct gravimetric quantification of biomass is usually not possible when natural solid substrates are used, due to the close association of the microorganism with the substrate. During the development of an alternative model system based on j-carrageenan which facilitates the quantitative recovery of biomass dry matter (Weber, Tramper, & Rinzema, 1999), we found that magnesium is very important for sporulation. The present study evaluates the eect of several minerals in combination with various gelling agents on sporulation of C. minitans. We demonstrate that the amount of freely diusible magnesium strongly aects the spore yield. Furthermore, we demonstrate that the gelling agent used to mimic solid substrate cultivation may produce artefacts in medium optimization studies.

Water-extractable humic substances enhance iron deficiency responses by Fe-deficient cucumber plants

The ability of Fe-deficient cucumber plants to use iron complexed to a water-extractable humic substances fraction (WEHS), was investigated. Seven-day-old Fe-deficient plants were transferred to a nutrient solution supplemented daily for 5 days with 0.2 μM Fe as Fe-WEHS (5 μg org. C mL-1), Fe-EDTA, Fe-citrate or FeCl3. These treatments all allowed re-greening of the leaf tissue, and partial recovery of dry matter accumulation, chlorophyll and iron contents. However, the recovery was faster in plants supplied with Fe-WEHS and was already evident 48 h after Fe supply. The addition of 0.2 μM Fe to the nutrient solution caused also a partial recovery of the dry matter and iron accumulation in roots of Fe-deficient cucumber plants, particularly in those supplied with Fe-WEHS. The addition of WEHS alone (5 μg org. C mL-1, 0.04 μM Fe) to the nutrient solution slightly but significantly increased iron and chlorophyll contents in leaves of Fe-deficient plants; in these plants, dry matter accumulation in leaves and roots was comparable or even higher than that measured in plants treated with Fe-citrate or FeCl3. After addition of the different iron sources for 5 days to Fe-deficient roots, morphological modifications (proliferation of lateral roots, increase in the diameter of the sub-apical zones and amplified root-hair formation) and physiological responses (enhanced Fe(III)-chelate reductase and acidification of the nutrient solution) induced by Fe deficiency, were still evident, particularly in plants treated with the humic molecules. The presence of WEHS caused also a further acidification of the nutrient medium by Fe-deficient plants. The Fe-WEHS complex (1 μM Fe) could be reduced by intact cucumber roots, at rates of reduction higher than those measured for Fe-EDTA at equimolar iron concentration. Plasma membrane vesicles, purified by two-phase partition from root microsomes of Fe-deficient plants, were also able to reduce Fe-WEHS. Results show that Fe-deficient cucumber plants can use iron complexed to water soluble humic substances, at least in part via reduction of complexed Fe(III) by the plasma membrane Fe(III)-chelate reductase of root cells. In addition, the stimulating effect of humic substances on H+ release might be of relevance for the overall response of the plants to iron shortage.

Effects of Urea, Bermudagrass Hay and Molasses Additions to and Covering of Deep-Stacked Broiler Litter on Nutritive Value

Wang, Z.S., Goetsch, A.L., Patil, A.R., Rossi, J.E., Kouakou, B., Park, K.K. and Galloway, D.L. Sr, 1997. Effects of urea, bermudagrass hay and molasses additions to and covering of deep-stacked broiler litter on nutritive value. J. Appl. Anim. Res., 12: 49–70. Broiler litter was deep-stacked with bermudagrass hay (Cynodon dactylon) or molasses added singly at 0, 5, 10 or 20% (dry matter; DM) or in 1:1 (DM) mixtures at 0, 10 or 20% (DM). Urea was included at 0, 2.8 or 5.6% (DM) and substrates were placed in duplicate dacron bags in the center of deep-stacks of broiler litter with the same levels of urea either covered with plastic or left open. Recovery of neutral detergent fiber (NDF; ash-free) was decreased more (interaction; P<0.05) by urea with open than with covered litter and was less (P<0.05) for 5.6 vs 2.8% urea (67, 58 and 54% with open litter and 75, 60 and 56% with covered litter for 0, 2.8 and 5.6% urea, respectively; SE 1.2). Molasses addition decreased (P<0.05) and 10 or 20% bermudagrass inclusion increased (P<0.05) NDF recovery (62, 56, 56 and 55% with molasses and 62, 62, 68 and 73% with bermudagrass at 0, 5, 10 and 20%, respectively; SE 1.4). Recovery of neutral detergent soluble organic matter (NDSOM) was not affected (P>0.05) by treatments with covered litter and with open litter NDSOM recovery was similar between bermudagrass and malasses substrates. Overall, increases in 12-h in situ ruminal DM disappearance due to urea inclusion coincided with changes in concentrations and recoveries of NDF and NDSOM regardless of air exposure treatment and carbonaceous feedstuff source and level and treatments other than urea had relatively small effects. Treatment effects on 48-h DM disappearance were small in magnitude. Mixtures of bermudagrass and molasses added to broiler litter resulted in expected changes based on additive effects of singular additions. In conclusion, only urea improved nutritive value as assessed by chemical analyses and in situ digestibility, although changes appeared restricted to fiber solubilization. Source and level of added carbonaceous feedstuff and air exposure treatment did not appreciably alter urea effects.

Nutrient conservation of baled hay by sprayer application of feed grade fat with or without barn storage

Protection from precipitation increases nutrient recovery from hay. In June of 1992 a third year stand of alfalfa (Medicago sativa L.) was harvested as baled hay. The experiment was conducted as a completely randomized two way analysis of variance. Hay bales were selected at random, (n = 40), numbered, weighed, core sampled, and assigned to either being stored in a ‘Barn’ or outside as ‘No Barn’. The bales were then assigned to the factor of ‘Fat’ or ‘No Fat’. The Fat factor was the sprayer application of choice white grease at 2% of bale weight. No Fat did not have any fat applied. Baled hay chemical composition at first sampling was: moisture, 16.0%; crude protein, 15.78%: carotene, 18.7 mg kg−1. After one year, bales were visually appraised, weighed, and core sampled. Before and after samples were analyzed for moisture, crude protein, and carotene. Bales stored outside with fat appeared to have more deterioration than untreated outside bales. Fat and no fat treated bales stored in a bam appeared similar. Outside stored bales appeared more deteriorated than barn stored bales. Dry matter, crude protein, and carotene recovery were: Barn and Fat 91.7%, 85.6%, and 43.8%; Barn and No Fat: 92.2%, 85.7%, and 36.1%; No Barn and Fat: 56.5%, 46.4%, and 11.7%; No Barn and No Fat: 61.7%, 53.3%, and 15.6%. Nutrient recovery was significantly higher due to storage in a barn, and was not influenced by application of fat to the bales.

Comparison of methods for isolation of protozoa from ruminal fluid

Isolation of protozoa from ruminal fluid taken from the same cow on five different days was carried out by three methods based on sedimentaton or on filtration using 10-μm mesh (PMB-10) or 20-μm mesh (PMB-20) polyester monofilament bags. Differences among means for percentage recoveries of protozoal numbers for the three isolation methods were statistically significant (P = 0.007), but those for dry matter and diaminopimelic acid (DAPA) recoveries were not (P &gt; 0.1). The sedimentation method produced the lowest recovery of protozoa as well as the highest recovery of DAPA, which indicated the highest bacterial contamination. Among the filtration-based methods PMB-10 produced higher recoveries of protozoal numbers and dry matter than PMB-20, but with somewhat larger bacterial contamination. Among the three methods compared, filtration with PMB-10 was considered as the most suitable. Key words: Ruminal fluid, protozoal isolation, sedimentation, filtration

Nitrogen mineralization in native cultivated and abandoned fields in shortgrass steppe

We conducted a set of in situ incubations to evaluate patterns of N availability among dominant land uses in the shortgrass steppe region of Colorado, USA, and to assess recovery of soil fertility in abandoned fields. Replicated 30 d incubations were performed in 3 sets of native (never cultivated), abandoned (cultivated until 1937), and currently cultivated, fallow fields. Net N mineralization and the percentage of total N that was mineralized increased in the order: native, abandoned, cultivated. Higher soil water content in fallow fields is the most likely reason for greater mineralization in cultivated fields, while higher total organic C and C/N ratios in native and abandoned fields may explain differences in mineralization between these land uses. Recovery of soil organic matter in abandoned fields appears to involve accumulation of soil C and N under perennial plants, but probable methodological artifacts complicate evaluation of the role of individual plants in recovery of N availability. Higher N mineralization and turnover in cultivated fields may make them more susceptible to N losses; recovery of N cycling in abandoned fields appears to involve a return to slower N turnover and tighter N cycling similar to native shortgrass steppe.

Effects on milk production of feeding silage and sugar‐beet pulp as separate components, in a mixed ration or as an ensiled blend

AbstractTwenty early‐lactation British Friesian dairy cows were used in a five‐treatment, partially balanced change‐over design experiment, consisting of four periods each of 4 weeks' duration. Three treatments consisted of offering ensiled blends of silage and sugar‐beet pulp produced by mixing 40 (S40), 80 (S80) and 120 (S120)kg beet pulp t−1 herbage at ensiling. In two further treatments, an untreated silage was supplemented with 5 kg of beet pulp daily, either mixed with the silage prior to feeding (SM) or offered in two equal feeds each day (ST). Silage was offered ad libitum in all treatments, while in addition all cows received 1 kg d−1 of a concentrate supplement containing 470 g crude protein kg−1 fresh weight.Dry‐matter intakes and milk fat + protein yields increased with increasing level of beet pulp inclusion in the diet, irrespective of whether it was offered in the form of an ensiled blend or as a supplement to an untreated silage. With the exception of D‐value (digestible organic matter in the dry matter), which was significantly higher with treatments SM and ST than with the ensiled blend treatment (S80), no significant differences were identified in total ration digestibility or in the efficiency of nitrogen or energy utilization between methods of beet pulp inclusion in the diet. However, offering beet pulp in the form of an ensiled blend reduced the acetate/propionate ratio in rumen fluid compared with offering best pulp as a supplement to an untreated silage. When account is taken of differences in the efficiency of recovery of edible silage dry matter between ensilage systems and of differences in dry‐matter intakes between treatments, total milk fat + protein outputs per 10000 kg herbage dry matter ensiled were 55 (s.e. 50·9) and 78 (s.e. 47·5) kg lower when equal quantities of beet pulp were offered as part of an ensiled blend rather than as a supplement to an untreated silage, as in treatments SM and ST respectively. However, these differences were non‐significant. Alternatively, in order to produce an equal milk output from ensiling a given quantity of herbage, 12·5 and 16·2% more beet pulp would have been required if the beet pulp had been mixed with the herbage at ensiling, rather than offered as a supplement, as in treatments SM and ST respectively.

Effect of recombinant chymosin on ewes' milk coagulation and Manchego cheese characteristics

SummaryEwes' milk coagulation was significantly influenced by the type of rennet when recombinant chymosin produced by Kluyveromyces lactis was compared with two commercial calf rennets with declared chymosin contents of 55 and 70%. Recombinant chymosin and calf rennet with 70% chymosin exhibited similar thrombelastographic characteristics, and coagulated milk more rapidly than calf rennet with 55% chymosin. The type of rennet had no effect on Manchego cheese dry matter, pH or recovery of dry matter in cheese. N soluble at pH 4·6 was the only N fraction influenced by the type of rennet, with slightly higher levels for cheese made with recombinant chymosin or with calf rennet containing 70% chymosin than for that made with rennet containing 55% chymosin. No significant differences in rheological or sensory characteristics between Manchego cheese made with recombinant chymosin and that made with the calf rennets were detected.

Effects of ammoniation of brome-alfalfa and alfalfa hay, stored as large round bales on preservation and feed quality

Feeding trials with growing steers and digestibility trials with sheep were conducted during each of 3 yr in a split-split plot design, to compare the effects of anhydrous ammonia (2% wt wt−1, in plastic-covered stacks of large round bales) on preservation of brome-alfalfa and alfalfa hay harvested at &lt; 20 and at 30% moisture with respective field cured (&lt; 20% moisture) nonammoniated hays. Even after 14 wk of storage, the ammoniated high-moisture hays were free of visible molds. Dry matter (DM) recovery varied from 93.9 to 98.7% but was not affected by either moisture content or ammoniation. Ammoniation increased (P &lt; 0.05) acid detergent insoluble nitrogen (ADIN, % total N) in high-moisture brome-alfalfa hay to 16.8 from 9.7% in nonammoniated hay. Within each type of hay, dry matter intake and average daily gain of growing steers were not affected by treatment. Feed efficiency was reduced (P &lt; 0.05) in animals fed ammoniated high-moisture brome-alfalfa (11.2) but was improved (P &lt; 0.05) in those fed ammoniated high-moisture alfalfa (9.8) when compared with the respective field cured hay (10.1 and 11.4). Compared to nonammoniated hay, ammoniating high-moisture brome-alfalfa hay had no effect on digestibilities of DM and acid detergent fiber (ADF) but decreased and increased (P &lt; 0.05) digestibility of nitrogen (N) and neutral detergent fiber (NDF), respectively. With alfalfa, ammoniation did not affect digestibilities of either low- or high-moisture hay. Rumen volatile fatty acid profiles were not influenced but rumen fluid pH was elevated in sheep fed ammoniated hays. Results indicate that anhydrous ammonia treatment effectively preserved high-moisture alfalfa without adversely affecting nutritional quality parameters. Key words: Ammonia, brome-alfalfa, alfalfa, cattle, sheep, digestibility

An Investigation of the Treatment and Recycling of Oil Refinery Wastewater

The objective of the present investigation was a high level of purification of the wastewater from an oil refinery achieved by using some improved methods yielding an effluent suitable for recycling into the process. All the investigations were carried out on a continuous laboratory pilot system consisting of the following units: dissolved air flotation (DAF), sedimentation, double-stage microbiological reactor, and adsorption columns filled with granular biologically activated carbon (GBAC). A high degree of COD reduction close to 100% (precisely, 99.95 %), as well as removal of nitrogen compounds of 72% was achieved during a relatively short retention time within the range of 15-16.5 hrs. The DAF technique combined with gravitational separation was used to achieve the recovery of free oil matter up to 98%, without any preliminary conditioning. After the sedimentation of coagulated and flocculated dispersed oils, the microbiological oxidation of dissolved matter was accomplished by using two kinds of activated sludge for easy and hard degradable organics. Using the continuously bioregenerating GBAC, an effluent having a lowered COD value to about 9 was obtained. At the same time, the denitrification process took place. According to the obtained results the treated oil refinery wastewater can be recycled into the process, or discharged into a water recipient of a low self-purifying capacity.