949 research outputs found
Effects of forage supplements on milk production and chemical properties, in vivo digestibility, rumen fermentation and N excretion in dairy cows offered red clover silage and corn silage or dry ground corn
peer-reviewedThis study concerned the effects of partial substitution of clover silage with high starch forages on milk production and chemical composition, in vivo digestibility, rumen
fermentation pattern and nitrogen excretion of dairy cows. Sixteen dairy cows were
separated into two groups and were assigned to treatments in a two-period crossover
design. Two forage supplements were used: corn silage (CS) and dry ground corn (DG).
All animals received 4.5 kg of concentrate dry matter per day. Results showed no significant
difference between the forage supplements for milk production, while significant
differences (P<0.01) were observed for milk fat, milk protein and nitrogen utilisation
efficiency (42 v. 4.0 g/kg, 3.5 v. 3.3 g/kg and 222 v. 188 g/kg, respectively, for DG and CS).
Faecal N excretion did not differ between forage supplements, but urinary N excretion
was higher for CS (P<0.05). No significant differences were observed between treatments
for rumen fluid pH or for rumen fluid concentrations of ammonium nitrogen
or of acetic, propionic or butyric acids. Dry matter intake and the in vivo digestibility
of dry matter, organic matter, acid detergent fibre and neutral detergent fibre were all
higher for CS compared with DG.The authors are grateful to the Environmental Office
of the Cantabrian Government for funding the project
05-640.02-2174
Electronic States in Diffused Quantum Wells
In the present study we calculate the energy values and the spatial
distributions of the bound electronic states in some diffused quantum wells.
The calculations are performed within the virtual crystal approximation, spin dependent empirical tight-binding model and the surface Green
function matching method. A good agreement is found between our results and
experimental data obtained for AlGaAs/GaAs quantum wells with thermally induced
changes in the profile at the interfaces. Our calculations show that for
diffusion lengths {\AA} the transition (C3-HH3) is not
sensitive to the diffusion length, but the transitions (C1-HH1), (C1-LH1),
(C2-HH2) and (C2-LH2) display large "blue shifts" as L_{D} increases. For
diffusion lengths {\AA} the transitions (C1-HH1) and (C1-LH1)
are less sensitive to the L_{D} changes than the (C3-HH3) transition. The
observed dependence is explained in terms of the bound states spatial
distributions.Comment: ReVTeX file, 7pp., no macros, 4 figures available on the reques
Comparison of micrometeorological techinques for estimating ammonia emission from covered slurry storage and land spreading of cattle slurry
The micrometeorological mass-balance integrated horizontal flux (IHF) technique has been commonly employed for measuring ammonia (NH3) emissions inon-field experiments. However, the inverse-dispersion modeling technique, such as the backward Lagrangian stochastic (bLS) modeling approach, is currently highlighted as offering flexibility in plot design and requiring a minimum number of samplers (Ro et
al., 2013). The objective of this study was to make a comparison between the bLS technique with the IHF technique for estimating NH3 emission from flexible bag storage and following landspreading of dairy cattle slurry. Moreover, considering that NH3 emission in storage could have been non uniform, the effect on bLS estimates of a single point and multiple downwind concentration measurements was tested, as proposed by Sanz et al. (2010)
Influence of the formulation on double emulsions containing ecological ingredients prepared by a microfluidic technique
Multiple emulsions have significant potential in
myriad applications, including foods, cosmetics,
drop networks, controlled microreactors, synthesis
of microcapsules and drug delivery systems. Great
control of multiple-emulsion drops production can
be achieved using microfluidic devices. The field of
emulsification through microfluidic devices has in recent years become a popular topic of research.
In this work, we used a practical approach to make
monodisperse double-emulsions drops with an ultrathin middle layer using a single step emulsification in a capillary microfluidic device. The goal of
this study was to investigate the influence of different
surfactants and additives on stability and droplet size
of W/O/W eco-friendly emulsions formulated with
a green solvent (D-Limonene). The incorporation of
Pluronic F108 destabilised the double emulsions due
to a process of precipitation, forming microcapsules.
By contrast, there was a necessity to include Span 80
in the formulation in order to achieve stable double
emulsions. The addition of rosin gum or silicone oil
did not show any improvement in the stability of these
complex emulsions. Finally, the formulation used in
ultrathin shell microfluidic device did not produce
stable double emulsions in the traditional microfluidic device.Las emulsiones múltiples tienen multitud de aplicaciones en la industria alimentaria, cosméticos, microreactores controlados, síntesis de microcápsulas y
sistemas de liberación controlada. Se puede conseguir
un gran control de la producción de gotas en emulsiones dobles usando técnicas microfluídicas.
En este trabajo se desarrollaron emulsiones dobles
formuladas con D-Limoneno usando un dispositivo
de microfluídica en un solo paso. El D-Limoneno, el
componente principal del aceite esencial de naranja,
es un monoterpeno natural que tiene propiedades antioxidantes, bactericida, quimiopreventivas y terapéuticas. El objetivo del presente estudio fue investigar la
influencia de diferentes tipos de tensioactivos y aditivos en la formulación de emulsiones dobles ecológicas
tipo corteza-ultrafina-núcleo sobre la estabilidad física. Las emulsiones dobles tipo corteza ultra fina y núcleo preparadas con Pluronic P108 sufrieron un fenómeno de desestabilización debido a la precipitación de
este tensioactivo polimérico creando microcápsulas.
Las emulsiones dobles necesitaron un tensioactivo hidrófobo (Span 80) en la fase media para estabilizarlas.
Se consiguieron emulsiones dobles estables utilizando
Span 80 como tensioactivo en la fase oleosa y PVA
en la fase exterior para la configuración tipo corteza ultrafina-núcleo. Estas condiciones no son extrapolables al tradicional dispositivo de microfluídica.Ministerio de Economía y Competitividad del Gobierno de España-CTQ2015-70700-PComisión Europea (Programa FEDER)-CTQ2015-70700-
Murciano-Granadina goat performance and methane emission after replacing barley grain with fibrous by-products
[ES] El objetivo de este trabajo fue estudiar los efectos de la sustitución de grano de cebada en la
dieta por pulpa de naranja o vainas de soja en el balance de nitrógeno y carbono, las
emisiones de metano y el rendimiento de la producción de leche en cabras. Para ello, se
seleccionaron doce cabras lecheras Murciano-Granadina y se dividieron en tres grupos
basados en un peso corporal similar (42,1 ± 1,2 kg) y la producción de leche (2,16 ± 0,06
kg/cabra/día). El experimento se realizó en un diseño cruzado donde un grupo de cuatro
cabras fue alimentado con una ración mixta de grano de cebada, en otro grupo de cuatro
cabras se reemplazó el grano de cebada por pulpa de naranja y el último grupo de cuatro
cabras se alimentó con soja. Después de la adaptación a las dietas, las cabras se
establecieron en jaulas individuales y se analizaron las heces, la orina y la leche. Asimismo,
las mediciones de intercambio gaseoso fueron registradas por un sistema móvil de calorimetría en circuito abierto. El consumo de materia seca fue similar en los tres grupos (2,03 kg/d, en promedio). No se observó ninguna influencia de la dieta en el balance energético. Las dietas basadas en pulpa de naranja y cascarilla de soja mostraron una mayor movilización de grasa que en el caso de grano de cebada. El ácido pentadecanoico y el ácido heptadecanoico fueron potenciales biomarcadores de la función del rumen debido a los contenidos más elevados encontrados en la leche de cabras con la dieta de pulpa de naranja y vainas de soja frente al detectado en las cabras con dieta de grano de cebada, lo que sugiere un impacto de estas dietas sobre el metabolismo bacteriano rumen. Esto probablemente esté relacionado con un suministro de nitrógeno inferior
en el caso de la dieta de pulpa de naranja para sintetizar proteína microbiana y un mayor contenido de grasa en el caso de la dieta de cascarilla de soja. La sustitución de grano de cereal con
subproductos fibrosos no aumentó las emisiones de metano (54,7 L/cabra por día, en promedio). Por lo tanto, se podría utilizar pulpa de naranja y cascarilla de soja en la dieta de las cabras lactantes sin tener un impacto negativo en el rendimiento de la producción de leche.[EN] The aim of this experiment was to study the effects of substituting dietary barley grain with orange pulp or soybean hulls on energy, nitrogen and carbon balance, methane emission and milk performance in dairy goats. Twelve Murciano-Granadina dairy goats in midlactation were selected and divided into three groups based on similar body weight (42.1 +/- 1.2 kg) and milk yield (2.16 +/- 0.060 kg/goat/day). The experiment was conducted in an incomplete crossover design where one group of four goats was fed a mixed ration of barley grain (BRL), another group of four goats replaced barley grain with orange pulp (OP) and the last group of four goats with soybean hulls (SH). After adaptation to diets, the goats were allocated to individual metabolism cages and intake, faeces, urine and milk were recorded and analysed. Then, gas exchange measurements were recorded by a mobile open-circuit indirect calorimetry system using a head box. Dry matter intake was similar for all three groups (2.03 kg/d, on average). No influence of the diet was observed for energy balance and the efficiency of use of metabolizable energy for milk production was 0.61. The OP and SH diets showed greater (P th Symposium on Energy Metabolism. EAAP. Publ. 11. Academic Press, London.Brouwer E (1958) On simple formulae for calculating the heat expenditure and the quantities of carbohydrate and fat metabolized in ruminants, from data on gaseous exchange and urine N. Pages 182–194 in Proc. 1th Symposium on Energy Metabolism. EAAP. Publ. 8. Academic Press, London.Chwalibog, A., Tauson, A.-H., & Thorbek, G. (1997). Quantitative oxidation of nutrients in growing calves. Zeitschrift für Ernährungswissenschaft, 36(4), 313-316. doi:10.1007/bf01617806Casper, D. P., Maiga, H. A., Brouk, M. J., & Schingoethe, D. J. (1999). Synchronization of Carbohydrate and Protein Sources on Fermentation and Passage Rates in Dairy Cows,,. Journal of Dairy Science, 82(8), 1779-1790. doi:10.3168/jds.s0022-0302(99)75408-1Aguilera, J. F., Prieto, C., & FonollÁ, J. (1990). Protein and energy metabolism of lactating Granadina goats. British Journal of Nutrition, 63(2), 165-175. doi:10.1079/bjn19900104Tovar-Luna, I., Puchala, R., Sahlu, T., Freetly, H. C., & Goetsch, A. L. (2010). Effects of stage of lactation and dietary concentrate level on energy utilization by Alpine dairy goats. Journal of Dairy Science, 93(10), 4818-4828. doi:10.3168/jds.2010-3315Bava, L., Rapetti, L., Crovetto, G. M., Tamburini, A., Sandrucci, A., Galassi, G., & Succi, G. (2001). Effects of a Nonforage Diet on Milk Production, Energy, and Nitrogen Metabolism in Dairy Goats throughout Lactation. Journal of Dairy Science, 84(11), 2450-2459. doi:10.3168/jds.s0022-0302(01)74695-4López, M. C., & Fernández, C. (2013). Energy partitioning and substrate oxidation by Murciano-Granadina goats during mid lactation fed soy hulls and corn gluten feed blend as a replacement for corn grain. Journal of Dairy Science, 96(7), 4542-4552. doi:10.3168/jds.2012-6473Palmquist, D. L., & Jenkins, T. C. (1980). Fat in Lactation Rations : Review. Journal of Dairy Science, 63(1), 1-14. doi:10.3168/jds.s0022-0302(80)82881-5Kebreab E, Strathe AB, Dijkstra J, Mills JAN, Reynolds CK, Crompton LA, et al. (2010) Energy and protein interactions and their effects on nitrogen excretion in dairy cows. Pages 417–426 in Symp. on Energy and Protein Metabolism and Nutrition, Parma, Italy.Chilliard, Y., Ferlay, A., Rouel, J., & Lamberet, G. (2003). A Review of Nutritional and Physiological Factors Affecting Goat Milk Lipid Synthesis and Lipolysis. Journal of Dairy Science, 86(5), 1751-1770. doi:10.3168/jds.s0022-0302(03)73761-8Vlaeminck, B., Fievez, V., Cabrita, A. R. J., Fonseca, A. J. M., & Dewhurst, R. J. (2006). Factors affecting odd- and branched-chain fatty acids in milk: A review. Animal Feed Science and Technology, 131(3-4), 389-417. doi:10.1016/j.anifeedsci.2006.06.017Fievez, V., Colman, E., Castro-Montoya, J. M., Stefanov, I., & Vlaeminck, B. (2012). Milk odd- and branched-chain fatty acids as biomarkers of rumen function—An update. Animal Feed Science and Technology, 172(1-2), 51-65. doi:10.1016/j.anifeedsci.2011.12.008Vlaeminck, B., Gervais, R., Rahman, M. M., Gadeyne, F., Gorniak, M., Doreau, M., & Fievez, V. (2015). Postruminal synthesis modifies the odd- and branched-chain fatty acid profile from the duodenum to milk. Journal of Dairy Science, 98(7), 4829-4840. doi:10.3168/jds.2014-9207Jorjong, S., van Knegsel, A. T. M., Verwaeren, J., Bruckmaier, R. M., De Baets, B., Kemp, B., & Fievez, V. (2015). Milk fatty acids as possible biomarkers to diagnose hyperketonemia in early lactation. Journal of Dairy Science, 98(8), 5211-5221. doi:10.3168/jds.2014-8728Ulbricht, T. L. V., & Southgate, D. A. T. (1991). Coronary heart disease: seven dietary factors. The Lancet, 338(8773), 985-992. doi:10.1016/0140-6736(91)91846-mKnapp, J. R., Laur, G. L., Vadas, P. A., Weiss, W. P., & Tricarico, J. M. (2014). Invited review: Enteric methane in dairy cattle production: Quantifying the opportunities and impact of reducing emissions. Journal of Dairy Science, 97(6), 3231-3261. doi:10.3168/jds.2013-7234Angelidaki, I., & Sanders, W. (2004). Assessment of the anaerobic biodegradability of macropollutants. Reviews in Environmental Science and Bio/Technology, 3(2), 117-129. doi:10.1007/s11157-004-2502-3Velthof, G. L., Nelemans, J. A., Oenema, O., & Kuikman, P. J. (2005). Gaseous Nitrogen and Carbon Losses from Pig Manure Derived from Different Diets. Journal of Environmental Quality, 34(2), 698-706. doi:10.2134/jeq2005.0698Jarret, G., Cozannet, P., Martinez, J., & Dourmad, J. Y. (2011). Effect of different quality wheat dried distiller’s grain solubles (DDGS) in pig diets on composition of excreta and methane production from faeces and slurry. Livestock Science, 140(1-3), 275-282. doi:10.1016/j.livsci.2011.04.006Triolo, J. M., Sommer, S. G., Møller, H. B., Weisbjerg, M. R., & Jiang, X. Y. (2011). A new algorithm to characterize biodegradability of biomass during anaerobic digestion: Influence of lignin concentration on methane production potential. Bioresource Technology, 102(20), 9395-9402. doi:10.1016/j.biortech.2011.07.026Klevenhusen, F., Kreuzer, M., & Soliva, C. R. (2010). Enteric and manure-derived methane and nitrogen emissions as well as metabolic energy losses in cows fed balanced diets based on maize, barley or grass hay. animal, 5(03), 450-461. doi:10.1017/s1751731110001795SPEK, J. W., DIJKSTRA, J., VAN DUINKERKEN, G., & BANNINK, A. (2012). A review of factors influencing milk urea concentration and its relationship with urinary urea excretion in lactating dairy cattle. The Journal of Agricultural Science, 151(3), 407-423. doi:10.1017/s0021859612000561Van Knegsel, A. T. M., van den Brand, H., Dijkstra, J., van Straalen, W. M., Heetkamp, M. J. W., Tamminga, S., & Kemp, B. (2007). Dietary Energy Source in Dairy Cows in Early Lactation: Energy Partitioning and Milk Composition. Journal of Dairy Science, 90(3), 1467-1476. doi:10.3168/jds.s0022-0302(07)71632-
Quantum Monte Carlo Studies of Relativistic Effects in Light Nuclei
Relativistic Hamiltonians are defined as the sum of relativistic one-body
kinetic energy, two- and three-body potentials and their boost corrections. In
this work we use the variational Monte Carlo method to study two kinds of
relativistic effects in the binding energy of 3H and 4He. The first is due to
the nonlocalities in the relativistic kinetic energy and relativistic one-pion
exchange potential (OPEP), and the second is from boost interaction. The OPEP
contribution is reduced by about 15% by the relativistic nonlocality, which may
also have significant effects on pion exchange currents. However, almost all of
this reduction is canceled by changes in the kinetic energy and other
interaction terms, and the total effect of the nonlocalities on the binding
energy is very small. The boost interactions, on the other hand, give repulsive
contributions of 0.4 (1.9) MeV in 3H (4He) and account for 37% of the
phenomenological part of the three-nucleon interaction needed in the
nonrelativistic Hamiltonians.Comment: 33 pages, RevTeX, 11 PostScript figures, submitted to Physical Review
Exact 4He Spectral Function in a Semirealistic NN Potential Model
The spectral function of 4He is calculated with the Lorentz integral
transform method in a large energy and momentum range. The excitation spectrum
of the residual 3N-system is fully taken into account. The obtained spectral
function is used to calculate the quasi elastic longitudinal (e,e') response
R_l of 4He for q=300, 400, and 500 MeV/c. Comparison with the exact R_l shows a
rather sizeable disagreement except in the quasi elastic peak, where the
differences reduce to about 10% at q=500 MeV/c. It is shown as well that very
simple momentum distribution approximations for the spectral function provide
practically the same results for R_l as the exact spectral function.Comment: 7 pages, Latex (Revtex), 4 Postscript figures, to appear in Phys.
Rev.
Efecto de herbicidas post-emergentes aplicados en distintos estados del cultivo de trigo (Triticum aestivum L.)
Se analizó la respuesta del cultivo de trigo (Triticum aestivum L.) cv. Buck Charrúa a varios herbicidas aplicados en diferentes estadios del cultivo y la eficacia de los mismos sobre el control de malezas. Las malezas no provocaron daño al cultivo, ya que no se afectó el rendimiento y componentes. Disminuciones significativas de rendimiento se obtuvieron con la utilización de mezcla de 2,4-0 Picloram y 2,4-0 + Dicamba aplicados con posterioridad a alcanzado el estado de espiguilla terminal diferenciada. En tal situación, el porcentaje de control de malezas fue de apenas el 26 %. Bromoxinil, Dicamba Metsulfurón metil, Dicamba MCPA Terbutrina + Triasulfurón y Metsulfurón metil aplicado en estado de ápice vegetativo· 2,4-0 + Dicamba, Bromoxinil y Dicamba MCPA aplicados en doble arruga y 2,4-0 + Dicamba y Dicamba + MCPA aplicados previos a e piguilla terminal diferenciada no produjeron disminución significativa de rendimiento y el porcentaje de control de malezas fue alrededor del 63% con todos esos productos medidos en antesis del cultivo. Este mismo porcentaje de control se obtuvo con la mezcla 2,4-0 Picloram aplicada en doble arruga y previo a espiguilla terminal diferenciada sin embargo e registró disminución de rendimiento por fitotoxicidad. Las mermas de producción observadas se debieron principalmente al componente granos/espiga.Director: Ing. Agr. Fernando D. García, Cátedra Terapéutica Vegetal, Facultad de Agronomía
Ammonia and greenhouse gas emissions from an enriched cage laying hen facility
[EN] Ammonia, methane, nitrous oxide and carbon dioxide emissions were measured during a
complete production cycle in an enriched cage laying hen facility under Oceanic climate
conditions. Continuous monitoring of gas concentration, ventilation rate and environmental
parameters were conducted from April 2012 to September 2013. The seasonal and
diurnal pattern of gas emissions was analysed.
Seasonality effect was found for NH3 emission, showing an average emission of
144.9 mg d 1 hen 1 and 90.3 mg d 1 hen 1 in summer and winter, respectively. On the
contrary, diurnal pattern of NH3 emission did not differ between these seasons. For CO2,
mean emission values did not show seasonality, although the diurnal pattern differed
between winter and summer. Results obtained for CH4 and N2O emissions did not provide
sufficient evidence to determine either seasonality or diurnal effect on these gases.
An NH3 emission factor of 7% of total N in manure was defined for this system. These
losses increased at higher ventilation rates and lower belt cleaning frequencies. Thus, NH3
mitigation strategies at housing level should consider both parameters. Further studies
would be necessary to determine how these factors regulate NH3 emission at laying hen
houses.
© 2016 IAgrE. Published by Elsevier Ltd. All rights reservedThis work has been funded by BATFARM Interreg-Atlantic Area Project (2009-1/071) entitled "Evaluation of best available techniques to decrease air and water pollution in animal farms". Oier Alberdi holds a grant from the Ph.D. student's research program of the Department of Economic Development and Competitiveness of the Basque Government. The authors are especially grateful to Larrabe Oilotegia S.A.T. that facilitated productive data and access to the farm and to the engineering company Ingenieria Avicola S.L. for the detailed information on ventilation aspects of the installation.Alberdi, O.; Arriaga, H.; Calvet, S.; Estellés, F.; Merino, P. (2016). Ammonia and greenhouse gas emissions from an enriched cage laying hen facility. Biosystems Engineering. 144:1-12. doi:10.1016/j.biosystemseng.2016.01.009S11214
Weak Transitions in A=6 and 7 Nuclei
The He beta decay and Be electron capture processes are studied using
variational Monte Carlo wave functions, derived from a realistic Hamiltonian
consisting of the Argonne two-nucleon and Urbana-IX three-nucleon
interactions. The model for the nuclear weak axial current includes one- and
two-body operators with the strength of the leading two-body term--associated
with -isobar excitation of the nucleon--adjusted to reproduce the
Gamow-Teller matrix element in tritium -decay. The measured half-life of
. He is under-predicted by theory by 8%, while that of Be for
decay into the ground and first excited states of Li is over-predicted by
9%. However, the experimentally known branching ratio for these latter
processes is in good agreement with the calculated value. Two-body axial
current contributions lead to a 1.7% (4.4%) increase in the value of
the Gamow-Teller matrix element of He (Be), obtained with one-body
currents only, and slightly worsen (appreciably improve) the agreement between
the calculated and measured half-life. Corrections due to retardation effects
associated with the finite lepton momentum transfers involved in the decays, as
well as contributions of suppressed transitions induced by the weak vector
charge and axial current operators, have also been calculated and found to be
negligible.Comment: 23 pages 8 tables. submitted to Phys. Rev.
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