Estimation of intake and digestibility of kleingrass from in situ parameters measured in sheep

The voluntary intake and digestibility of kleingrass (Panicum coloratum cv. Verde) were measured in seven periods, comprising one full year. The forage was offered twice a day ad Iibitum to .seven rams, frtted with faces collection bags; each experimental period was composed of 8 days for adaptation and 8 days for collection of data. The dry matter (DM) Intake (DMI) varied from 36.1 to 64.9 glkg MO.75, the digestible dry-matter Intake (DDMI), from 17.4 to 41.9 glkg MO.75 and the in vivo dry matter apparent digestibility (DMD), from 0.471 to 0.667. Daily samples of offered forage were taken and pooled subsamples from each of the seven periods were incubated in nylon bags in the rumen of three Hereford steers. The data were fitted to the exponential equation: p= a + b (1-e~) to estimate p (the proportionate loss of DM at time t of incubation); effective degradability (ED) and lag time (L) were also estimated. The parameters obtained in situ were related to the in vivo results by simple and multiple regression. The correlation coefficients of the rate of degradation {9 and ED with DMI, DDMI and DMD were, respectively, 0.96 and 0.97; 0.97 and 0.96; 0.86 and 0.88. By including, Q, Q and k into a multiple regression analysis, the coefficients of determination (R2) were: DMI: 0.99; DDMI: 0.99 and DMD: 0.91. Within the conditions of this study, the parameters obtained in situ were reasonable estimators of voluntary intake and digestibility.Resúmenes de Trabajos presentados en otras publicaciones (por docentes de la UNLPam.) Publicado en Animal Science, 67: 535-540, 1998

Intake Estimation of Rams under Grazing Condition in a Deferred Pastures of \u3ci\u3ePanicum coloratum\u3c/i\u3e by Two Techniques

The goal of this study was to quantify the organic matter intake (OMI) of Pampinta rams grazing in a Panicum coloratum cv Verde differed pasture. The OMI was compared by two methods: a) the difference between the forage measured in pre and post-grazing condition, and b) the faecal production:digestibility ratio of the diet, estimated by total faecal gathering, and from the quantity of total faecal N in g per 100 g-1 of OMI and the concentration of total faecal N, respectively. The OMI estimated by difference between the forage measured in pre and post-grazing was 9 % higher (P\u3c 0,05) than the one estimated from total faecal gathering and OMD. Interaction was not detected (P\u3e 0,10) between treatments (length of the deferment period) and estimation method. The use of the faecal N can be utilized, considering the time of the year, to estimate the OMD and OMI in grazing condition in P. coloratum deferred pastures

Dry matter production and nutritive value of forage of Digitaria eriantha cv. Irene in two locations oft be central semi-arid region of Argentina

The aim of this experiment was to compare dry matter (DM) production rates and nutritive value of a warm-season grass, Digitaria erisntha ev. Irene, in two locations of Central Argentina, Santa Rosa (SR) and Villa Mercedes (VM). The plants were established in two identical groups of plots, within a randomized block design DM rates were calculated from serial, out of phase clippings, and in vitro dry matter digestibility (IVDMD) and crude protein (CP) content analyzed on subsamples. The study lasted for three consecutive growing seasons. Results showed that DM production rates were generally higher (P<0.05) in SR than in VM, but IVDMD and CP content showed no clear trends between both locations. DM production tended to lower from year 1 to 3, related to processes of N depletion from soils (VM) and diminishing rainfall (SR). It is concluded that D. eriantha is a very promising warm-season grass to Central Argentina. Data of nutritive value obtained in one location can be used in others, but results of DM production rates should be taken under the conditions where they will be used.Resúmenes de Trabajos presentados en otras publicaciones (por docentes de la UNLPam.)  Publicado en Proceedings of the XVIII international grassland congress. Forage and Management, Session 22: 101-102, 1997

Contenido de Iignina como estimador de la degradabilidad ruminal en gramíneas

The objective of this study was to establish the relationship between lignin content and the degradable fraction of warm-season grasses. The 120 samples used came from plots of the following species, Eragrostis curvula ev. Tanganyka (Ee), Panicum virgatum ev. Pathfinder (Pv), Panicum coIoratum ev. Selection 75 (Pe) and Tetrachne dregeí (Td). The samples were obtained during two consecutive winters, in 1990/91. The forage obtained was divided into its fractions, blade and stem+sheath, on which Iignin content (L) was determined. Each fraction was incubated within nylon bags, in the rumen of three fístulated steers. The Information obtained from incubations was mathematically processed to estimate the asymptote of the hyperbole (Dmax), and, through a non-linear model, the rapidly (a) and slowly (b) degradable dry malter values were determined. The contents of L were related to the values obtained by rumen incubation y, = (a+b) and Y2 = Dmax. Pseudovarlables were used to discriminate between grass species: Ee (Pv, Pe and Td=0); Pv (Pv = 1; Pe and Td=0); Pe (Pe = 1; Pv and Td=0);Td (Td=1; Pv and Pe=0). The equations obtained were, y, = 102.6 - 6.97L + 21.57Pv + 7.70Pe - 1.82L*Pe; R2 = 0.68(P<0.01), SE = 7.8; Y2 = 73.10 - 3.72L + 43.72Pv - 5.55L*Pv + 26.76Pe - 2.85L*Pc + 25.69Td - 3.44L*Td; R2 = 0.77(P<0.01), SE = 5.8. The results demonstrate that, the degradable fraction of warm-season grasses can be estimated by the Iignin content of the forage source.El objetivo de este estudio fue establecer la relación existente entre el contenido de lignina con la fracción degradable en gramíneas perennes de crecimiento estival. Se tomaron 120 muestras provenientes de parcelas implantadas con Eragrostis curvula ev Tanganyka (Ec), Panicum virgatum ev Pathfinder (Pv), Panicum coloratum ev Selection 75 (Pc) y Tetrachne dregel (Td) cortadas durante dos inviernos, en 1990/91. En las muestras, previa división en las fracciones lámina y tallo+vaina, se determinó el contenido de Iignina (L) y fueron incubadas en bolsitas en el rumen de tres novillos. A partir de la información obtenida en la incubación se estimó la asíntota de la hipérbola (Cmax) y, a través de un modelo no lineal, los valores de materia seca rápida (a) y lentamente (b) degradable. Los contenidos de L fueron relacionados con v,=(a+b) e VI=Cmax. Para diferenciar entre gramlneas se utilizaron pseudovariables, Ee (Pv, Pe V Td=0); Pv (Pv=1; Pe y Td=0); Pe (Pc=1; Pv Y Td=0); Td (Td=1; Pv Y Pc=0). Las ecuaciones obtenidas fueron, V, = 102,6 - 6,97L + 21,57Pv + 7,70Pc - 1,82L*Pe; R2 = 0,68(P<0,01); EE = 7,8; VI = 73,10 - 3,72L + 43,72Pv - 5,55L*Pv + 26,76Pc - 2,85L*Pe + 5,69Td· 3,44L*Td; R2 = 0,77(P<0,01);EE = 5,8. Se concluye que conociendo el contenido en lignina, para gramíneas perennes de crecimiento estival, puede estimarse la fracción degradable

Efecto de la suplementación con jugos de fruta sobre el ambiente y la digestión de forrajes en rumen

The use of fruit juice as energy supplement to beef cows have been increasing in La Pampa Province during the last years. The aim of the present study was to measure the effect of the addition of fruit juice to an alfalfa hay diet, on rumen environment and forage digestion. Six rumen fistulated steers were used within a cross-over design, with two treatments and two perlods. The animals were fed ad libitum on alfalfa hay. This diet was supplemented with 4.47 mi Kg LWO·7S.d" of distilled water (To) or fruit juice (T,), via rumen cannulae twice a day (8:00 and 16:00 h). After seven days of adaptation to the diets, samples of rumen liquid were taken at 8:00, 10:00 and 14:00 h (16, 2 and 6 h after supplementation of water or juice) during tour consecutive days. Concentration of ammonia nitrogen (NH)-N), volatile fatty acids NFA) and pH were determined on the rumen samples. The rumen digestion of DM and CP of leaves of alfalfa hay and DM of deferred weeping lovegrass hay was measured through the in sacco technique. The results were analyzed by ANOVA. The pH values were different (To= 6.60; T1 = 6.35; P = 0.051) after 2 h of supplementation, but no differences were found after 6 h (To= 6.50; T1 = 6.40; P = 0.130) or 16 h (To= 6.33 T1 = 6.17; P = 0.169). The VFA concentrations showed a trend to signification (in mM) (To= 76.3 T1 = 71.3; P = 0.094) at 6 h, although no treatment effect could be detected at 2 h (To= 74.8; T1 = 80.7; P = 0.293) or 16 h (To= 85.7; T1 =  84.6; P = 0.866). The supplementation with fruit Juice had no effect on rumen ammonia concentration (in mg.l-1 of NH3-N): 2 h: To= 237.0; ; T1 = 230.6; P = 0.522; 6 h To= 210.0; ; T1 =197.2; P = 0.356; 16 h: TD = 215.8; ; T1 = 196.7; P = 0.154. The addition of fruit juice to the diet To= 67.8;  T1 =  67.6; P = 0.831 and deferred weeping lovegrass hay: T0 = 23.1; T1 = 22.2; p". 0.421. The ED of CP of Ieaves of alfalfa hay showed a trend to be higher when only distilled water was added (To = 47.4; T1 = 45.6; P = 0.107). In the conditions of this assay, the supplementation of fruit juice to fibrous diets did not produce clear effects on rumen environment and digestion that could affect the nutritional status.La utilización de Jugos de fruta como suplemento energético en vacas de cria ha tomado gran importancia en la Provincia de La Pampa, durante los últimos años. El objetivo del presente estudio fue determinar el efecto de la adición de Jugo de fruta a una dieta de heno de alfalfa sobre el ambiente ruminal y la digestión ruminal. Se utilizaron seis novillos fistulados en el rumen, en un diseño cross-over de dos tratamientos y dos periodos. Los animales recibieron, sd libitum, heno de alfalfa, a esta dieta se adicionaron 4,47 mi Kg. PV0.75.d-1 de agua destilada (To) o jugo de fruta (T1), ambos fueron suministrados a través de cánula ruminal dos veces al día (8:00 y 16:00 h). Después de 7 días de acostumbramiento a los tratamientos se extrajeron muestras de líquido ruminal a las 2, 6 Y 16 h posteriores al suministro del agua o jugo, durante cuatro días consecutivos en cada periodo. Sobre las muestras extraídas se determinó pH, concentración de nitrógeno amoniacal (N-NH3 y ácidos grasos volátiles (AGV). La degradación de la materia seca (MS) y proteína bruta (pe) en el rumen fue medida sobre hojas de heno de alfalfa y sobre MS de heno de pasto llorón diferido, a través de la técnica in sacco. Los resultados fueron analizados mediante ANOVA. El pH difirió (To :1 6,60; T1 = 6,35; P = 0,051) luego de dos horas de la adición de jugo, mientras que no fue distinto a las 6 h (To = 6,50; T1 = 6,40; p= 0,130) ni a las 16 h (To = 6,33; T1=6,17; p= 0,169). En AGV (en mM) se observó una tendencia a la significación (To= 76,3; T1= 71,3; P :1 0,094) a las 6 h, mientras que no hubo efecto de tratamiento a las 2 h (To= 74,8; T1= 80,7; P = 0,293) ni a las 16 h (To= 85,7; T1 = 84,6; P= 0,866). No se detectó efecto alguno de la suplementación con jugo sobre la concentración de amoniaco ruminal (en mg l-1, de N-NH3): 2 h: Te = 237,0; T, = 230,6; P = 0,522; 6 h: To= 210,0; T1= 197,2; P= 0,356; 16 h: To = 215,8; T1= 196,7; P= 0,154. La adición de Jugo no influyó sobre la degradabilidad efectiva (DE) in sacco de la materia seca de hojas de alfalfa (DE: To= 67,8; T1= 67,6; p =0,831) Y de heno de pasto llorón diferido (DE: Te = 23,1; T, = 22,2; P = 0,421). La DE de la PB de hojas de heno de alfalfa presentó una tendencia a ser mayor cuando se agregó agua destilada (To = 47,4; T1= 45,6; P = 0,107). En las condiciones del ensayo, la suplementaci6n con Jugos de fruta sobre una dieta fibrosa no produjo efectos claros sobre el ambiente ruminal que afecten el status nutricional.Trabajo presentado en el 20° Congreso Argentino de Producción Animal, junio de 1996, Río Hondo, Santiago del Estero

Comparación de dos técnicas de estimación del consumo y digestibilidad en pastoreo de Panicum coloratum L. diferido

Voluntary intake (OMI) and digestibility (OMD) of organic matter were estimated on a deferred pasture of Panicum coloratum L., using grazing rams, by two different methods. Four treatments, corresponding to tour forage allowances (in g. DM. Kg-1 ot liveweight.day-1) were established: T1: 15; T2: 30; T3: 45; T4: 60. Six Pampinta rams by treatment grazed during 22 days, being the last 6 days the measurement period The first method estimated OMI as the difference between initial and final biomass (OMldir), and digestibility (OMDdir) from OMldir, and fecal organic matter production (F). The second method of estimation used Iignin as internal marker. The organic matter digestibility (OMO~ was estimated through the concentrations of Iignin in diet and faeces, and the voluntary intake (OMILDA), from (OMDLDA) and F. No differences (p>0.05) between treatments could be detected in any of the measured variables. The OMI, as estimated through both methods, were highly correlated (r = 0.97; p<0.01). II seems Iikely that Iignin ls a suitable internal marker in Panicum coloratum L. Both, digestibility and voluntary in lake of grazing animals can be estimated through this technique, with good precision.Sobre una pastura de Panicum coloratum L. diferida, se estimó el consumo voluntario (CMO) y la digestibilidad (DMO) de la materia orgánica, por dos métodos distintos, utilizando ovinos en pastoreo. Se establecieron cuatro tratamientos, correspondientes a cuatro asignaciones forrajeras (en g MS.Kg-1 de peso vívo.dia-1): T1: 15; T2: 30; T3: 45; T4: 60. En cada tratamiento pastorearon 6 carneros Pampinta durante 22 días, con cambio diario de parcela, correspondiendo los 6 últimos al período de medición. En el primer método, el CMO se estimó por diferencia entre la biomasa inicial y final (CMOdir), y la digestibilidad (DMOdir a partir de CMOdir, y la producción de materia orgánica en heces (H). El segundo método de estimación fue a través de la utilización de Iignina como marcador interno. Se estableció la digestibilidad de la materia orgánica (DMOLDA) a través de la concentración de Iignina en dieta y heces, y el consumo voluntario (CMOLDA) a partir de DMOLDA y H. En ninguna de las variables estimadas se encontraron diferencias (p>0,05) entre tratamientos. El CMO, estimado a través de ambos métodos, tuvo alta correlación (r = 0,97; p<0,01). También el grado de asociación de la DMO fue alto, aunque algo menor entre los métodos (r = 0,84; p<0,01). La Iignina tiene buen comportamiento como marcador interno en Panicum coloratum L. Mediante esta técnica, puede estimarse la digestibilidad y el consumo voluntario de animales en pastoreo con buena precisión

Main Results of Phase IV BEMUSE Project: Simulation of LBLOCA in an NPP

Phase IV of BEMUSE Program is a necessary step for a subsequent uncertainty analysis. It includes the simulation of the reference scenario and a sensitivity study. The scenario is a LBLOCA and the reference plant is Zion 1 NPP, a 4 loop PWR unit. Thirteen participants coming from ten different countries have taken part in the exercise. The BEMUSE (Best Estimate Methods plus Uncertainty and Sensitivity Evaluation) Programhas been promoted by theWorking Group on AccidentManagement and Analysis (WGAMA) and endorsed by the Committee on the Safety of Nuclear Installations (CSNI). The paper presents the results of the calculations performed by participants and emphasizes its usefulness for future uncertainty evaluation, to be performed in next phase. The objectives of the activity are basically to simulate the LBLOCA reproducing the phenomena associated to the scenario and also to build a common, well-known, basis for the future comparison of uncertainty evaluation results among different methodologies and codes. The sensitivity calculations performed by participants are also presented. They allow studying the influence of different parameters such as material properties or initial and boundary conditions, upon the behaviour of the most relevant parameters related to the scenario

Evaluation of developmental neurotoxicity: some important issues focused on neurobehavioral development

Exposure of the developing organism to industrial chemicals and physical factors represents a serious risk factor for the development of neurobehavioral disorders, such as attention-deficit hyperactivity disorder, autism and mental retardation. Appropriate animal models are needed to test potentially harmful effects and mechanisms of developmental neurotoxicity of various chemical substances. However, there are significant human vs. rat differences in the brain developmental profile which should be taken into account in neurotoxicity studies. Subtle behavioral alterations are hard to detect by traditional developmental toxicity and teratogenicity studies, and in many cases they remain hidden. They can however be revealed by using special behavioral, endocrine and/or pharmacological challenges, such as repeated behavioral testing, exposure to single stressful stimulus or drugs. Further, current neurobehavioral test protocols recommend to test animals up to their adulthood. However some behavioral alterations, such as anxiety-like behavior or mental deficiency, may become manifest in later periods of development. Our experimental and scientific experiences are highly suggestive for a complex approach in testing potential developmental neurotoxicity. Strong emphasis should be given on repeated behavioral testing of animals up to senescence and on using proper pharmacological and/or stressful challenges

Socially and biologically inspired computing for self-organizing communications networks

The design and development of future communications networks call for a careful examination of biological and social systems. New technological developments like self-driving cars, wireless sensor networks, drones swarm, Internet of Things, Big Data, and Blockchain are promoting an integration process that will bring together all those technologies in a large-scale heterogeneous network. Most of the challenges related to these new developments cannot be faced using traditional approaches, and require to explore novel paradigms for building computational mechanisms that allow us to deal with the emergent complexity of these new applications. In this article, we show that it is possible to use biologically and socially inspired computing for designing and implementing self-organizing communication systems. We argue that an abstract analysis of biological and social phenomena can be made to develop computational models that provide a suitable conceptual framework for building new networking technologies: biologically inspired computing for achieving efficient and scalable networking under uncertain environments; socially inspired computing for increasing the capacity of a system for solving problems through collective actions. We aim to enhance the state-of-the-art of these approaches and encourage other researchers to use these models in their future work