Seleeniaineenvaihdunta maitoa tuottavalla vuohella ja lehmällä

The objective of this study was to investigate the metabolism of inorganic and organic Se sources at different dietary Se levels in lactating goats and dairy cows. The study consists of two experiments on goats dosed singly, either orally with grass sprayed with Na275SeO3 one week before cutting, intraruminally (I.R.) with Na275SeO3, or intravenously (I.V.) with Na275SeO3 or 75Se-selenomethionine. Follow-up periods were from 15 to 28 d long. Dietary Se levels were 0.05, 0.22 and 0.34 mg/kg DM. Values for 75Se absorption, excretion in milk, urine and faeces, 75Se activity in plasma, erythrocytes and hair are presented. In another experiment lasting 539 d, 48 dairy cows were fed either Na275SeO3 or grass silage sprayed with Na275SeO3 one week before cutting. Dietary Se levels were from 0.03 to 1.8 mg/kg DM. Se content in milk, plasma and erythrocytes, and GSH-Px activity in erythrocytes and plasma are given. True absorption of 75Se was 63 % and 65 %, and excretion of 75Se in milk 4 % and 7 % in the goats dosed I.R. with Na275SeO3 and orally with 75Se-labeled grass. The effect of dietary Se content was non-significant. After I.V. dose, 3.6 % and 33 % of 75Se was excreted in milk in goats dosed with Na275SeO3 and 75Se-selenomethionine, respectively, Na275SeO3 being eliminated mainly via urine. In cows receiving selenium as Na275SeO3, milk contained 0.011, 0.011, 0.016 and 0.020 mg Se/l at dietary Se levels 0.11, 0.17, 0.42 and 0.68 mg/kg DM, respectively. In cows receiving Se-sprayed silage, milk Se content was 0.023, 0.020, 0.029 and 0.040 mg/l when the diet contained 0.09, 0.20, 0.45 and 1.20 mg Se/kg DM. Se incorporated into silage was more efficient (pTutkimuksen tarkoituksena oli selvittää epäorgaanisen ja orgaanisen seleenin aineenvaihduntaa maitoa tuottavilla vuohilla ja lypsylehmillä useilla seleenitasoilla. Tutkimus koostuu kahdesta vuohilla ja yhdestä lehmillä suoritetusta kokeesta. Vuohille annettiin kerta-annoksena joko viikoa ennen niittoa Na275SeO3:llä ruiskutettua ruohoa, pötsinsisäisesti (I.R.) Na275SeO3:ä tai suonensisäisesti (I.V.) Na275SeO3 tai 75Se-selenometioniinia. Seurantajaksojen pituus oli 15—28 d. Käytetyt seleenitasot olivat 0.05, 0.22, ja 0.34 mg Se/kg ka. Tulokset esitetään 75Se imeytymisestä, erittymisestä maidossa, virtsassa ja sonnassa sekä 75Se-aktiivisuudesta plasmassa, erytrosyyteissä ja karvassa. Lehmillä suoritettu koe kesti 539 d ja siinä 48 lehmälle annettiin joko Na2SeO3:ä tai säilörehua, jolle oli viikkoa ennen korjuuta ruiskutettu Na2SeO3:ä. Dieetin seleenipitoisuus vaihteli välillä 0.03 ja 1.8 mg Se/kg ka. Tulokset esitetään maidon, plasman ja erytrosyyttien seleenipitoisuudesta sekä plasman ja erytrosyyttien GSH-Px -aktiivisuudesta. 75Se todellinen imeytyminen oli 63 %ja 65 % sekä erittyminen maidossa 4 % ja 7 % vuohilla, joille annettiin Na275SeO3 I.R. tai 75Se:llä leimattua ruohoa. Dieetin seleenipitoisuudella ei ollut vaikutusta 75Se:n imeytymiseen tai erittymiseen maidossa. Kun 75Se annettiin LV., 3.6 % seleniitistä ja 33 % selenometioniinista erittyi maidossa. Na275SeO3 erittyi pääasiassa virtsassa. Lehmillä, joilla Na2SeO3 oli seleenin lähteenä, maidon seleenipitoisuus oli 0.011, 0.011, 0.016 ja 0.020, kun dietin seleenipitoisuus oli 0.11, 0.17, 0.42 ja 0.68 mg Se/kg ka. Selenoidun säilörehun ollessa seleenin lähteenä maidon seleenipitoisuus oli 0.023, 0.020, 0.029 ja 0.040 mg/l dieetin seleenipitoisuudenollessa 0.09, 0.20, 0.45 ja 1.20 mg/kg ka. Selenoitu säilörehu nosti maidon seleenipitoisuutta voimakkaammin (

Effects of winter feeding strategies with alternative feeds on the performance of mature suckler cows and their progeny

The present study evaluated the effects of feeding strategies with alternative feeds on the performance of mature suckler cows and their progeny during indoor feeding and subsequent grazing. In both experiments, a 2 × 2 factorially arranged design consisted of two feeding strategies (Step-up, S; Flat-rate, F) and two diets (Control, C; Alternative, A). The aim of Strategy F was to offer the cows the same amount of energy as offered on Strategy S, but at a constant daily level. In Experiment 1, cows on Diet C were offered grass silage and straw and on Diet A grass silage and a fl our-mill industry by-product. On Strategy S, feeding was stepped with barley (0, 1.5 and 3.5 kg d-1). On Strategy F, barley was offered 1.43 kg per head daily. In Experiment 2, cows were offered either grass silage (C) or whole-crop barley silage (A) as a sole feed. Strategy S was carried out by offering 68, 95 and 119 MJ metabolizable energy (ME) per cow daily. On Strategy F, roughage was given daily 97 MJ ME. In both experiments, there were no signifi cant differences between treatments in the cow live weight, body condition score, calf pre-weaning live weight gain and cow reproduction. Strategy F can be practised in the nutrition of mature suckler cows in marginal circumstances. Flour-mill industry by-product can partly replace grass silage and straw in the winter diet. Wholecrop barley silage can be offered as a sole feed to suckler cows with good body condition score in autumn

Metabolism of selenite, selenomethionine and feed-incorporated selenium in lactating goats and dairy cows

The objective of this study was to investigate the metabolism of inorganic and organic Se sources at different dietary Se levels in lactating goats and dairy cows. The study consists of two experiments on goats dosed singly, either orally with grass sprayed with Na275SeO3 one week before cutting, intraruminally (I.R.) with Na275SeO3, or intravenously (I.V.) with Na275SeO3 or 75Se-selenomethionine. Follow-up periods were from 15 to 28 d long. Dietary Se levels were 0.05, 0.22 and 0.34 mg/kg DM. Values for 75Se absorption, excretion in milk, urine and faeces, 75Se activity in plasma, erythrocytes and hair are presented. In another experiment lasting 539 d, 48 dairy cows were fed either Na275SeO3 or grass silage sprayed with Na275SeO3 one week before cutting. Dietary Se levels were from 0.03 to 1.8 mg/kg DM. Se content in milk, plasma and erythrocytes, and GSH-Px activity in erythrocytes and plasma are given. True absorption of 75Se was 63 % and 65 %, and excretion of 75Se in milk 4 % and 7 % in the goats dosed I.R. with Na275SeO3 and orally with 75Se-labeled grass. The effect of dietary Se content was non-significant. After I.V. dose, 3.6 % and 33 % of 75Se was excreted in milk in goats dosed with Na275SeO3 and 75Se-selenomethionine, respectively, Na275SeO3 being eliminated mainly via urine. In cows receiving selenium as Na275SeO3, milk contained 0.011, 0.011, 0.016 and 0.020 mg Se/l at dietary Se levels 0.11, 0.17, 0.42 and 0.68 mg/kg DM, respectively. In cows receiving Se-sprayed silage, milk Se content was 0.023, 0.020, 0.029 and 0.040 mg/l when the diet contained 0.09, 0.20, 0.45 and 1.20 mg Se/kg DM. Se incorporated into silage was more efficient (

Modelling Cross-Border Rail Intermodality in the Windsor-Essex Context

Shipment by truck dominates the cross-border flow of commodities in both directions between Canada and the United States (Anderson and Coates, 2010; Anderson, 2012; Anderson and Brown, 2012; and Aspila and Maoh, 2014). An individual truck typically pulling one or two trailers is an inefficient way to move goods over long distances (Eom et al., 2012) when freight trains with three or more 4400 horsepower diesel-electric locomotives pull over two-hundred intermodal containers loaded on rail cars throughout North America every day. Windsor, Ontario is an example of a border community in Canada and hosts the busiest border crossing between Canada and the United States. Crossings include two road, one rail and a sea port of entry (United States Department of Transportation – Bureau of Transportation Statistics, 2017). Presently the majority of cross-border import and export traffic is by road haulage. In addition to serving as a port of entry for goods being imported or exported between the two countries there is also a substantial local manufacturing base that consumes and produces goods on both sides of the border. There are several existing railroad border crossings including a rail tunnel between Windsor, Ontario and Detroit, Michigan. There must be a rational reason why commodities are shipped across the border using trucks and not rail. This dissertation research is proposed to answer the question of is rail viable for shipping commodities cross-border or as part of the cross-border supply chains? A network optimization model of Canada-US rail freight is developed to address this question. The model is first used to assess whether location of a conventional, large-scale intermodal facility in Windsor is viable. Results indicate that it is not. It is then applied to a scenario where innovative small-scale intermodal transfer facilities are located in Windsor and at other significant rail nodes in Ontario. Results indicate that this is a more viable strategy for increasing the rail share of cross-border freight movement

Rapeseed fat in dairy cow feeding

Dairy cows on silage and hay-based diets were given a barley-oats concentrate mixture containing 13 % rapeseed feed in four different forms: diet 1)rapeseed meal, 2)rapeseed meal + rapeseed oil, 3) rapeseed meal + crushed rapeseed and 4) protected fatty rapeseed meal. The fat content of the rapeseed feed was: diets 2 and 3, 7,1 % of dry matter; diet 4, 6.3 %; diet 1, 2.4 %. From the rapeseed the cows received only about 2 g digestible crude fat/kg 4 % FCM, the total fat supply on diets 2, 3 and 4 being 15 g digestible crude fat/kg 4 % FCM. At so low a level, the rapeseed fat did not have any clear effect on the milk fat or milk protein contents, or on the iodine number or fatty acid composition of the milk fat. The milk yield increased, however, when the diet contained rapeseed feed

Ultimate failure load analysis of cross-laminated timber panels subjected to in-plane compression

Cross-laminated timber (CLT) panels have proved their efficiency as vertical and horizontal load-carrying structures, and their design methods for serviceability and ultimate limit states are well defined. However, there is a lack of more general and versatile analytical methods for the ultimate load carrying capacity determination of CLT structures. In this paper, the classical layered beam theory is adopted for the ultimate failure load estimation of axially compressed CLT panels. The proposed method retains its accuracy both with an asymmetric layer setup and when the number of CLT layers exceeds five. The presented method is validated by adopting experimental test data from two test series produced by other researchers.publishedVersionPeer reviewe

Elastic design of steel-timber composite beams

In this paper, the well-known elastic theory of layered beams (ETLB) is employed for the structural analysis of steel-timber composite (STC) floors, where the cross-laminated timber (CLT) slabs are located on top of a steel beam and assuming the linear elastic behaviour of the STC structure. In the analysis, the CLT slab is homogenized, i.e. the lamellas are replaced by a uniform fictitious material such that the resulting slab has equivalent selected structural properties to the original. Two homogenization methods are presented and compared for selected cases. The first method (EI-equivalent) is based on the bending stiffness of the CLT cross-section, where the shear factor is obtained by the Gamma method. The second method (EA-equivalent) enforces equal axial stiffness for the homogenized slab. The two methods are compared against full-scale test results available in the literature, including static four-point bending tests, and dynamic test cases. The goal is to explore the usability of the ETLB for STC structures and examines which of the two homogenization methods provides more accurate results. Based on the evaluation of the experiments, it can be concluded that the ETLB yields an accurate analytical approach for STC structures, and both methods provide accurate results.publishedVersionPeer reviewe

Bacterially mediated removal of phosphorus and cycling of nitrate and sulfate in the waste stream of a "zero-discharge" recirculating mariculture system

Simultaneous removal of nitrogen and phosphorus by microbial biofilters has been used in a variety of water treatment systems including treatment systems in aquaculture. In this study, phosphorus, nitrate and sulfate cycling in the anaerobic loop of a zero-discharge, recirculating mariculture system was investigated using detailed geochemical measurements in the sludge layer of the digestion basin. High concentrations of nitrate and sulfate, circulating in the overlying water (~15 mM), were removed by microbial respiration in the sludge resulting in a sulfide accumulation of up to 3 mM. Modelling of the observed S and O isotopic ratios in the surface sludge suggested that, with time, major respiration processes shifted from heterotrophic nitrate and sulfate reduction to autotrophic nitrate reduction. The much higher inorganic P content of the sludge relative to the fish feces is attributed to conversion of organic P to authigenic apatite. This conclusion is supported by: (a) X-ray diffraction analyses, which pointed to an accumulation of a calcium phosphate mineral phase that was different from P phases found in the feces, (b) the calculation that the pore waters of the sludge were highly oversaturated with respect to hydroxyapatite (saturation index = 4.87) and (c) there was a decrease in phosphate (and in the Ca/Na molar ratio) in the pore waters simultaneous with an increase in ammonia showing there had to be an additional P removal process at the same time as the heterotrophic breakdown of organic matter

Interactions of cage aquaculture in Nile Delta lakes: Insights from field data and models

In this paper, we present a cost-effective approach to the assessment of the impact of fish cage culture in transitional water bodies characterized by limited exchanges with the sea. The approach, previously applied to marine coastal areas, is based on two steps: (1) the application of a Lagrangian model, driven by purposely collected data concerning the local hydrodynamic, for an "a priori'' simulation of the dispersion of uneaten feed and fecal material from a cage; (2) the collection of a set of field data concerning both water column and sediment indicators, sensitive to the release of organic matter from a cage, along a transect: the latter is determined on the basis of the results provided by the dispersion model. The methodology was tested at a seabass/seabream farm located in a coastal lake on the Nile Delta, namely Lake Maryut. Model results indicated that the area impacted by the cage is relatively small, about 5 m from the edge of the cage: this finding was later corroborated by field observations. As far as the water column is concerned, Dissolved Inorganic Nitrogen was found to be higher near the farm. The most sensitive sediment indicators were found to be surface sediment TOC, and benthic macrofauna abundances, which were, respectively, higher and lower in the proximity of the farm. These findings suggest that a cost-effective monitoring programme of the environmental impact of intensive aquaculture could be implemented in Egyptian coastal Lakes, thus providing a science-based support to the implementation of the ecosystem approach to aquaculture in these important ecosystems. (C) 2016 Elsevier B.V. All rights reserved

Mobilisation of arsenic from bauxite residue (red mud) affected soils: effect of pH and redox conditions

The tailings dam breach at the Ajka alumina plant, western Hungary in 2010 introduced ~1 million m3 of red mud suspension into the surrounding area. Red mud (fine fraction bauxite residue) has a characteristically alkaline pH and contains several potentially toxic elements, including arsenic. Aerobic and anaerobic batch experiments were prepared using soils from near Ajka in order to investigate the effects of red mud addition on soil biogeochemistry and arsenic mobility in soil–water experiments representative of land affected by the red mud spill. XAS analysis showed that As was present in the red mud as As(V) in the form of arsenate. The remobilisation of red mud associated arsenate was highly pH dependent and the addition of phosphate to red mud suspensions greatly enhanced As release to solution. In aerobic batch experiments, where red mud was mixed with soils, As release to solution was highly dependent on pH. Carbonation of these alkaline solutions by dissolution of atmospheric CO2 reduced pH, which resulted in a decrease of aqueous As concentrations over time. However, this did not result in complete removal of aqueous As in any of the experiments. Carbonation did not occur in anaerobic experiments and pH remained high. Aqueous As concentrations initially increased in all the anaerobic red mud amended experiments, and then remained relatively constant as the systems became more reducing, both XANES and HPLC–ICP-MS showed that no As reduction processes occurred and that only As(V) species were present. These experiments show that there is the potential for increased As mobility in soil–water systems affected by red mud addition under both aerobic and anaerobic conditions