The effect of non-genetic factors on early weaning of segureña lambs.

Se analiza la influencia sobre el peso al destete precoz, comprendido entre los 16 y los 35 días de vida, en corderos de raza ovina Segureña, de los efectos fijos sexo, época de nacimiento, zona geográfica y tipo de parto de la oveja. Se analizaron los datos del peso de 27083 corderos pertenecientes al registro histórico de la Asociación Nacional de Criadores de Ovino Segureño – ANCOS – de los últimos 13 años. Fueron realizados análisis estadísticos en cada factor, basados en el test t para las medias, análisis de varianza y el test de Tuckey para analizar los grupos homogéneos. Se llevó a cabo un análisis de varianza multifactorial mediante la utilización del software IBM SPSS Statistics v.19, utilizando los factores no genéticos como efectos principales y considerando las interacciones dobles significativas. Los machos presentaron un peso promedio superior al de las hembras. El efecto de la época de nacimiento fue significativo (P0,05). Sin embargo, el tipo de parto influenció el peso promedio de una manera muy significativa (P<0,001), poniéndose de manifiesto que los corderos nacidos de partos simples fueron más pesados que los corderos nacidos de partos múltiples. Las interacciones dobles época de nacimiento × tipo de parto, zona geográfica × época de nacimiento y sexo × tipo de parto fueron significativas (P<0,001) para el modelo, que se presentó con un coeficiente determinativo (R2) de 0,127. Como conclusión general puede indicarse que los factores no genéticos tienen un papel muy importante en peso de los corderos de raza Segureña en el destete precoz. El conocimiento de la influencia de estos factores podrá ser útil en el desarrollo de estrategias de producción para que los promedios totales del peso puedan ser mejorados.Abstract The present work was carried out to study the effects on early weaning (between 16 and 35 days of age) of the fixed effects of sex, birth season, geographical area and birth status, on Segureña sheep breed. Weight data were collected from 27083 lambs from the historical records of the National Breeders Association of Segureño Sheep - ANCOS – from the past 13 years. Statistics analysis were performed on each factor, based on the t test for means, analysis of variance and Tuckey test to analyze the homogeneous subsets. An analysis of variance multifactorial was performed using IBM SPSS Statistics v.19 software, with the non-genetics factors as main effects and considering the significant double interactions. Males present a mean weight higher than females. Birth season had a significant effect (P0,05) the early weaning lambs weight. However, birth type affected significantly (P<0,001) the early weaning lambs weight, becoming evident that lambs born from single birth were heavier than the ones born from multiple birth. The model presented significant double interactions (P<0,001), birth season × birth type, geographical area × birth season and sex × birth type, presenting a determinative coefficient (R2) of 0,127. As general conclusion, the non-genetics factors have a very important effect over early weaning weight of Segureña sheep breed. This knowledge is useful on development of production strategies for the improvement of the final mean weight.info:eu-repo/semantics/publishedVersio

Structural and optical properties of MOCVD AllnN epilayers

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Characterization of the blue emission of Tm/Er co-implanted GaN

Comparative studies have been carried out on the cathodoluminescence (CL) and photoluminescence (PL) properties of GaN implanted with Tin and GaN co-implanted with Tin and a low concentration of Er. Room temperature CL spectra were acquired in an electron probe microanalyser to investigate the rare earth emission. The room temperature CL intensity exhibits a strong dependence on the annealing temperature of the implanted samples. The results of CL temperature dependence are reported for blue emission (similar to 477 nm) which is due to intra 4f-shell electron transitions ((1)G(4)-> H-3(6)) associated with Tm3+ ions. The 477 nm blue CL emission is enhanced strongly as the annealing temperature increases up to 1200 degrees C. Blue PL emission has also been observed from the sample annealed at 1200 degrees C. To our knowledge, this is the first observation of blue PL emission from Tin implanted GaN samples. Intra-4f transitions from the D-1(2) level (similar to 465 nm emission lines) of Tm3+ ions in GaN have been observed in GaN:Tm films at temperatures between 20-200 K. We will discuss the temperature dependent Tm3+ emission in both GaN:Tm,Er and GaN:Tm samples

Reliability-based design optimization of composite stiffened panels in post-buckling regime

This paper focuses on Deterministic and Reliability Based Design Optimization (DO and RBDO) of composite stiffened panels considering post-buckling regime and progressive failure analysis. The ultimate load that a post-buckled panel can hold is to be maximised by changing the stacking sequence of both skin and stringers composite layups. The RBDO problem looks for a design that collapses beyond the shortening of failure obtained in the DO phase with a target reliability while considering uncertainty in the elastic properties of the composite material. The RBDO algorithm proposed is decoupled and hence separates the Reliability Analysis (RA) from the deterministic optimization. The main code to drive both the DO and RBDO approaches is written in MATLAB and employs Genetic Algorithms (GA) to solve the DO loops because discrete design variables and highly nonlinear response functions are expected. The code is linked with Abaqus to perform parallel explicit nonlinear finite element analyses in order to obtain the structural responses at each generation. The RA is solved through an inverse Most Probable failure Point (MPP) search algorithm that benefits from a Polynomial Chaos Expansion with Latin Hypercube Sampling (PCE-LHS) metamodel when the structural responses are required. The results led to small reductions in the maximum load that the panels can bear but otherwise assure that they will collapse beyond the shortening of failure imposed with a high reliability

Physic-chemical study of the marismeña cattle breed meat in different fattening systems

Marismeña cattle breed is a feral population included in a pre-zootechnic agro-ecosystem, the Doñana protected area. In spite of these characteristics so exclusives, the absence of characterization of their products difficults the finding of a way of commercialization differentiated of the typical commerce, adding value to product by way of a differentiated quality. The preliminary results of a meat physic-chemical study are presented. Seventeen animals of the breed have been studied reared in two different systems of fattening: its natural context and a commercial fattening station. Meat shown significant differences between the management systems for the results of the chemical analysis and colour at 24 hours posmortem. Animals belonging to the extensive system shown meat low in fat, with a high percentage of humidity, and colour with lower tone of red (p<0.01) and yellow (p<0.001), when compared with intensive animals. Results demonstrated a differentiation between both systems, together with some arguments to differentiate the products of this breed in the market.El bovino Marismeño es una entidad racial asilvestrada incluida en un sistema agroecológico prezootécnico, el Espacio Natural de Doñana que no encuentra una vía de comercialización adecuada que la diferencie de lo típicamente comercial, y, por tanto, agregue valor para competir mediante una calidad diferenciada. En este trabajo se presentan los resultados preliminares del estudio físico-químico de la carne. Se han estudiado 17 animales de la raza en dos sistemas de terminación diferentes, su entorno natural (extensivo) y un cebadero comercial (intensivo). La carne mostró diferencias significativas entre los sistemas de producción para los resultados de los análisis químicos y el color a las 24 horas postmortem. Los animales del sistema extensivo mostraron carnes magras, con un alto porcentaje de humedad, y una coloración con menores intensidades de rojo (p<0,01) y amarillo (p<0,001), comparada con los animales del intensivo. Los resultados demuestran una diferenciación entre ambos sistemas, a la vez que se hallan algunas características que conducen a la diferenciación del producto de esta raza bovina en el mercado

First results in the study of the morphology present status of the andalusian black cattle breed

Andalusian Black cattle breed is in danger of extinction alter to go out of the border of the disappearance. Moreover, the present situation of the Spanish farming, its belonging to the Iberian Black branch, producing a high pressure from other related breeds with a better productive potentiality. Studies for the breed conservation have begun, among them, the morphological study. By the moment 3 different farms without known influences from other breeds and 24 adult females have been recorded for 14 quantitative morphological traits, and some qualitative such as front profile and coat colour. Studied individuals presented few morphological variation and it put the breed near of the breed morphological pattern updating.La raza Negra Andaluza se encuentra en peligro de extinción tras haber estado al borde de la desaparición. Además de la actual situación de la ganadería española, a lo anterior ha contribuido su pertenencia al tronco Negro Ibérico, y la gran presión que razas con un potencial más desarrollado han ejercido sobre ésta. Se han comenzado los estudios necesarios para la conservación de este recurso genético, entre ellos, el estudio morfológico. Hasta el momento se han estudiado 3 ganaderías diferentes sin influencia genética de otras razas y un total de 24 hembras adultas en las que se han tomado 14 medidas morfológicas. Además se han observado variables cualitativas, como el perfil y la capa. Los individuos estudiados presentan poca variación morfológica entre ellos y, por tanto, acercan a la actualización del patrón morfológico de la raza