Cultivation and anaerobic digestion of Scenedesmus spp. grown in a pilot-scale open raceway

Digestibility of a micro-algal mixture was evaluated by mesophilic anaerobic digestion in continuously-stirred tank reactors. The culture consisted primarily of Scenedesmus spp. continuously cultivated over a 6-month period in a 100 m2 raceway reactor instrumented to record pH, dissolved oxygen and temperature. The raceway received supplementary carbon in the form of flue gas from a diesel boiler (10% CO2) injected into a 1-m deep sump to control pH in the range 7.8–8.0. Dilution was optimised to biomass productivity and gave values of 10–15 and 20–25 g total suspended solids (TSS) m? 2 day? 1 in winter (December–February) and spring (April–May), respectively. The culture for the anaerobic digestion trial was harvested in February by centrifugation to give an algal paste containing 4.3% volatile solids (VS). Semi-continuous digestion at organic loading rates of 2.00, 2.75 and 3.50 g VS l? 1 day? 1 gave volumetric biogas productions of ~ 0.66, ~ 0.83 and ~ 0.99 l l? 1 day? 1, respectively. Specific methane yield ranged from 0.13 to 0.14 l CH4 g? 1 VSadded with biogas methane content ~ 62%. Overall the digestion process was stable, but only ~ 30% VS destruction was achieved indicating low biodegradability, due to the short retention times and the recalcitrant nature of this type of biomas

Does Gender Impact Technology Adoption in Dual-Purpose Cattle in Mexico?

This paper examines the role of women in the dual-purpose livestock system (DP) in Mexico through their technological adoption patterns and aims to evaluate whether there are significant differences between the technology adoption networks of men and women farmers. The sample was composed of 383 DP small farms with 20 or fewer cows and a high level of vulnerability. Social Network Analysis (SNA) was applied, and the centrality measures were calculated for the technological areas of management, feeding, genetics, reproduction, and animal health. Significant differences were found in reproduction levels between men and women farmers. Therefore, SNA was developed in this technological area where men mainly occupied central positions (brokers) while women were just close to the leaders in the network. The results have shown that farms run by women were smaller and presented higher levels of specialization and milk productivity (20% higher), and women prioritized those technologies linked to female reproductive efficiency. Moreover, women were deeply embedded in men’s networks through numerous ties and were capable of building connections with groups of farmers outside of their own group

Estructura poblacional del Podenco Andaluz

En nuestro país los libros genealógicos caninos están gestionados por la Real Sociedad de Razas Caninas en España, quien delega su mantenimiento y control en las distintas asociaciones de criadores afiliadas. En el caso de la raza Podenco Andaluz, la gestión del libro genealógico es especialmente compleja debido al aislamiento reproductivo entre las distintas variedades existentes que obliga el actual patrón racial. En el presente estudio analizamos la estructura genética de la población del Podenco Andaluz basándonos en los registros genealógicos de los cinco últimos años donde indagamos en los ratios por sexo, ratios por tallas, ratios por edades dentro de talla; su evolución durante este tiempo y su proyección el futuro. Asimismo, profundizamos en una análisis de los niveles de consanguinidad individuales de los ejemplares inscritos, así como del nivel de endogamia media de la población

Problems in the introduction of information in DAD-IS via internet

Only six coordinator of the countries enclosed in the European Regional Focal Point introduced the new information in DAD-IS via Internet, at least until the last workshop of the Point celebrated in Viena in summer of 1997. One of these countries was Spain and here we develop a brief description of the problems found in this activity.Los coordinadores de sólo seis países del Punto Focal Europeo introducen la nueva información en DAD-IS vía internet, al menos hasta la última reunión del punto celebrada en Viena en el verano de 1997. Uno de esos puntos fue España y aquí realizamos una breve descripción de la problemática encontrada en esta labor

Description of A call to action, an interactive CD-ROM for the conservation and management of the animal genetic resources

We describe the use and contents of the interactive CD-ROM titled A call to action, in which is enclosed most of the information from the interactive program DAD-IS, available via Internet, allowing the access to the information collected in the FAO’s data base to researchers, teacher, farmers, etc. without Internet connection.Se describe el contenido y uso del CD-ROM titulado A call to action, que incluye la mayor parte de la información disponible en el programa interactivo DAD-IS, asequible en Internet, lo que ofrece un acceso a la información disponible en las bases de datos de la FAO, a investigadores, docentes, técnicos, ganaderos, etc que no dispongan de conexión a la red

The Importance of Network Position in the Diffusion of Agricultural Innovations in Smallholders of Dual-Purpose Cattle in Mexico

The dual-purpose bovine production system (DP) is the most widespread small-scale model in Latin American tropics, where it constitutes a key tool in terms of food security. Most DPs are subsistence farms oriented to self-consumption, with a very low technology adoption rate. Hence, the main challenge is how to improve the technological level without compromising the system sustainability by applying land-sharing practices. Thus, through networks methodology, this paper analysed how farmers adopt reproductive technologies. The sample consisted of 383 very small farms of dual-purpose cattle. Seven reproduction technologies oriented to improve reproductive efficiency were evaluated: Breeding soundness evaluation in bulls, semen fertility evaluation, evaluation of female body condition, oestrus detection, pregnancy diagnosis, seasonal or continuous mating, and breeding policy. Social Network Analysis (SNA) allowed identifying adoption patterns, as the joint adoption of semen fertility evaluation, estrus detection, and pregnancy diagnosis, which were consider complementary technologies. Similarly, breeding soundness evaluation in bulls was found to be the most widely adopted technology. The results showed that these farmers presented a very low level of reproduction technology adoption rate and suggested that farmer’s affiliation with organizations such as the Livestock Groups for Technological Validation and Transfer (GGAVATT), and its network position had a significant impact on the level of technological adoption. In the first stage of adoption, this work highlighted the importance of centralized models from the GGAVATT to the farmers, related to the knowledge and absorption dynamic capabilities. In a later stage, decentralized models through technological leaders are a priority, related to integration and innovation dynamic capabilities

Morphometric study in black varieties of Iberian pig breed

We are presenting a morphological study of the black varieties of the Iberian pig breed considering the Lampiño, Entrepelado, Mamellado, Silvela and Mamellado x Silvela strains, according to the Association of Breeders (AECERIBER) criteria. From the quantitative variables study, few significative differences among strains and sexes has been found, with absence of interactions between both factors. Also a posteriori homogeneity among means has been found significative association between strains and the frequencies of the coat colour, the types of hair, the hear type and the complementary particularities in the females, while in males a total independence have been shown.Se presenta un estudio morfológico en las variedades negras del cerdo Ibérico considerándose como tales las estirpes Lampiña, Entrepelado, Mamellado, Silvela y Mamellado x Silvela, según los criterios de catalogación de la asociación de criadores AECERIBER. En el estudio de las variables cuantitativas se deducen escasas diferencias entre estirpes y entre sexos y ausencia de interacciones entre ambos factores. Asimismo se encuentra una gran homogeneidad entre estirpes en el estudio de comparación de medias. Para las variables cualitativas se encuentra asociación significativa entre estirpes y el color de la capa, el tipo de orejas, el tipo de pelo y las particularidades para la muestra de hembras mientras que en los machos hay independencia entre las estirpes y las variables estudiadas

Zootechnical evolution in the spanish merino in early times and future

The Spanish native Merino sheep breed is perhaps the most important of the Spanish zootechnical successes. The repercussion of this breed has evolved not only the animal production but also other aspects such as laws, language and the history of this country. Over the years the Spanish Merinos have found several difficulties that have produced many oscillations in their census. Among them, undoubtedly the most significative has been the falling down of the wool price in the sixties, which made a change in the productive objectives planned for the breed. Recently the Merinos Association of breeders have developed a programme of selection and improvement, presently in a great level. The philosophy of this programme is based on the improvement of meat characteristics with the selection of direct and maternal additive genotypes, maintaining the morphological characteristics and the rusticity of the breed. In this communication the master lines to design a competitive future for this breed are described.La raza ovina Merino Autóctono Español es, quizás, el más emblemático de los logros de la zootecnia española, es una raza cuya importancia ha arraigado no sólo en la producción animal sino incluso en otros aspectos como la legislación, el léxico y la historia de nuestro país. En el transcurrir de los años diferentes dificultades le han inducido a significativas oscilaciones censales, de entre ellas la más grave ha sido sin duda la caída de los precios de la lana en la década de los sesenta que obligó a un cambio de planteamientos en los objetivos productivos de esta raza. Fue necesaria una transformación urgente de unas poblaciones de doble función lana-carne a otras donde destacaran más los aspectos cárnicos. Recientemente la Asociación de Criadores de Ganado Merino ha implementado un Programa de Selección y Mejora que ya se encuentra a un gran nivel de desarrollo, y cuya filosofía se basa en la mejora de los caracteres cárnicos de esta raza a través de la selección del genotipo directo y materno, manteniendo las características raciales y rusticidad propias de la raza. En esta comunicación también se trazan las líneas para diseñar un futuro competitivo para la raza Merina

Morphometric study in red varieties of iberian pig breed and Jabugo spotted

We are presenting a morphological study of the red varieties (Torbiscal, Retinto Portugués, Retinto Extremeño, Dorado Gaditano) of the Iberian pig breed and Jabugo Spotted, according to the Association of Breeders (AECERIBER) criteria. We have obtained significant differences among strains and sexes in the quantitative variables analysed also interaction between both factors has been detected. The qualitative variables have shown independence between strains and coat colour, type of hears, type of hair for males and females. Only the complementary particularities have been associated to the strains.Se presenta un estudio morfológico en las variedades rojas del cerdo Ibérico (Torbiscal, Retinto Portugués, Retinto Extremeño, Dorado Gaditano) y Manchado de Jabugo, según los criterios de catalogación de la asociación de criadores AECERIBER. En el estudio de las variables cuantitativas se deducen diferencias significativas entre estirpes y entre sexos y existencia de interacciones entre ambos factores. Para las variables cualitativas encontramos independencia entre el tipo de estirpe y el color de la capa, el tipo de orejas y el tipo de pelo para la muestra de machos y hembras mientras que en caso de las particularidades complementarias los machos presentan asociación para esta variable