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Scotland’s coastal environment has many areas which are potentially suitable for sustainable aquaculture development. However previous studies have shown that aquaculture may have a detrimental impact on sensitive environments. The main objective of this study is to develop a holistic management tool for sustainable coastal marine aquaculture in the Western Isles of Scotland through development of a multi-faceted holistic model that allows consideration of sensitive environments. As the Scottish Government promotes better collaboration and integration of all involved in coastal zone governance (Baxter et al, 2008) this study illustrates the benefits to be gained from harmonized management of information in a Geographical Information System. GIS models are strong support tools designed to aid decision-making. The main strengths are that GIS can generate easily understandable visual displays of results which are based on robust models capable of incorporating vast amounts of spatial data and which can be predictive and can simulate future coastal environment scenarios. Within this study it is demonstrated that GIS-based models can successfully manage and manipulate a wide range of datasets that are essential components in the determination and management of suitable aquaculture locations. The GIS decision support tools evaluated and integrated in this study were based on four main sub models. These were Cage Site Suitability, Particulate Dispersion, Sensitivity Biodiversity Indicators and Visual Landscape Capacity. Exploration of a combination of these sub-models into an overall decision support system was also completed. All sub models developed were flexible, instrumentally coherent and communicatively balanced for the management and planning of the coastal environment . A sub-model was designed to evaluate and optimize the location of marine cage systems. This required development of data layers and modelled sub-components relevant to the important environmental and engineering factors affecting cage designs which included wave climate, bathymetric and substrate profiles. Three cage types were explored; those designed for sheltered, semi-exposed and exposed areas. These environmental factor layers were combined through weighting and Multi criteria evaluation consideration for each cage type. The resulting three sub-models indicated that while the archipelago has quite restricted development potential for cages designed for sheltered environments (91km2), there is a limited development potential for cages designed for semi exposed environments (1543km2) and an optimal potential for aquaculture development with cages designed for exposed environments (3103km2). The greatest potential environmental impact from aquaculture comes from particulate dispersion. Currently, assessing footprints of effect from fish farms is carried out on an individual site basis mostly at ten metre resolution. The sub-model successfully developed in this work resulted in a partially validated multisite particulate sub model at one metre resolution which implemented maximum current velocity as the friction/force image. The sub-model was run on a range of coastal loch fjord systems and demonstrated the variation in particulate dispersion patterns in each fjord system. In all the fjord systems modelled, even where farm sites are close neighbours, there appears to be minimal interaction in the particulate dispersion. While the particulate sub-model is effective and rapid to deploy for multiple sites, it requires further development in order to incorporate the quantitative aspects of particulate dispersion. Aquaculture biodiversity sensitivity indicators were evaluated and five main sub-components were developed; Species sensitive to Aquaculture, Endangered species, Species important to the Western Isles, important spawning and nursery areas and Protected Areas. The sub-model was constructed by combining these layers through weighting and Multicriteria evaluation. The outcomes indicated that within the study area there are 1168km2 (4% of study area) which are highly sensitive to aquaculture activity, although 20595km2 (65% of study area) has a biodiversity that is much less sensitive to aquaculture. This sub-model, and some of its components, can operate as a “stand alone” tool or can be combined into a larger framework. Little modification and re-parameterisation would be required to enable models to be developed to cover the whole of the Scottish coastline, or other coastal locations. Aquaculture can visually affect landscapes, seascapes and can adversely affect visual capacity of different areas. GIS was successfully applied to investigate this contentious issue. This comprehensive and flexible sub-model successfully develops Seascape and Landscape sensitivity analysis of aquaculture structures and also incorporated a novel approach to visual assessment through use of proportional assessment. Combining the sensitivity layers, 6448km2 of the waters of the archipelago (20% of study area) were categorized as having high capacity to incorporate new aquaculture developments, whilst 3301km2 (10% of study area) have a moderate capacity for new aquaculture structures and 1324km2 (4% of study area) have a low capacity for new developments. An overall conceptual framework was designed to explore two methods for the combination of the major sub-models in order to identify the most appropriate areas for sustainable aquaculture with consideration of possible conflicts including conservation issues. Initial evaluations involved the extraction of information from the component GIS sub-models into a structured database. The extracted data provides a range of information that can be used for statistical analysis and decision support, but which leaves the evaluation of the optimal siting of aquaculture at any location in the Western Isles in the hands of the database interrogator. The second method involved combining the sub-models within GIS whole considering trade offs in relation to conservation. This GIS combination of models indicated that, taking many factors into consideration, the Western Isles has 748km2 (2.5% of study area) appropriate for aquaculture development when implementing the C315 and whilst considering the interactions with conservation areas. There were 498km2 (1.6% of study area) appropriate for development when implementing the intermediate C250 cage types but only 15km2 (0.04% of study area) were appropriate for development based on the LMS cage designs for sheltered environments. Both analytical approaches had strengths and weakness and clearly both need to be used in combination to maximise the benefit of the GIS model outcomes. This study has demonstrated the ability to apply scientific rigour to spatial modelling of aquaculture problems including site suitability, biodiversity, landscape capacity and multi-site particulate dispersion. The various sub-models and their components sub-models can be stand-alone decision-making tools or combined into a holistic model which incorporates a flexible method of trade-off management. The range of GIS-based coastal analytical tools developed form the core of a decision support system that can enable the objective management of the increasing demands on the coastal zone, while having the capacity to bring together stakeholders, multiple agencies and governing bodies that are responsible for management and use of these precious and sometimes threatened resources.

Imprecise control of bovine oestrus and ovulation and the highly variable nature of the superovulatory response impedes use of reproductive technologies. The use of GnRH to control antral follicle development and, hence, the oestrous cycle was investigated using 40 maiden heifers. Two GnRH agonist sources (Fertagyl; Receptal) were tested at two frequencies (24; 48 hour) and luteinising hormone release profile; and pattern of antral follicle and luteal development were monitored. Post cessation of GnRH treatment gonadotrophin was given at either a fixed or variable time relative to oestrus and superovulatory response assessed. Basal LH values were unaffected by treatment. Treatment at 24, but not 48 hour intervals resulted in reduced LH response values. Fertagyl 24 hour treatment stimulated increased numbers of follicles to grow to 3-5 mm and 6-9 mm but inhibited growth to 10 mm, maturation and ovulation. Four waves of follicular development occurred in GnRH agonist, but not control, animals. Luteolysis and oestrus was delayed in a proportion of animals challenged with prostaglandin during GnRH agonist treatment. Exogenous gonadotrophin given at fixed time (day 10 1 where oestrus = day 0) post cessation of treatment, elicited a greater superovulatory response than when given at variable time. There was a positive relationship between number of ovulations and viable embryos; and a negative relationship between body weight and progesterone concentration and consequently superovulatory response. High superovulatory responses were observed when gonadotrophin treatment was initiated in the presence of an active corpus luteum and the absence of a dominant follicle. It was concluded that GnRH agonist given every 24 hours depleted LH reserves; allowed selection and dominance of antral follicles, but not maturation and ovulation; precluded prostaglandin induced luteolysis in some animals; and increased ovulations and embryos when gonadotrophin treatment was at a fixed time.

This study is a continuation of a project to characterise ASTM A437 Grade B4B martensitic stainless steel for use In Hitachi Canadian Industries Ltds (HCI) steam turbine casing bolts. ASTM A437 Grade B4B steel is commercially available and was chosen for the study due to its chemical similarity to a proprietary steel currently used by HCI.<p>High creep resistance is essential for any candidate so creep-rupture and creep-strain tests were performed at and above the intended service temperature of 538°C. Hardness measurements and transmission electron microscopy were performed on the steel in the as-received condition as well as on crept samples to determine the effect of elevated temperature on the development of the steels microstructure.<p>During testing, it was found that ASTM A437 Grade B4B steel has a well defined second stage leading to an abrupt transition into the third stage. The second stage begins in the first 10% of its creep life, while the third stage begins at 90% of its creep life. This equates to 5% and 30% of the final strain, respectively, with an average final strain of 20%.<p>Time-to-Rupture data show good similarity to the creep life as predicted using the Larson-Miller method. When plotted, the steady-state creep rate shows a definite correlation between the creep stress and temperature. From this an empirical relationship was developed to predict the steady-state creep rate.<p> Transmission electron microscopy (TEM) results showed a significant change in the icrostructure between crept and as-received steel. Coarsening of carbides along grain boundaries most likely led to a recovery of the microstructure in the crept samples. Literature suggests that the composition of the carbides is most likely tungsten and molybdenum intermetalics and carbides that coarsened from the depletion of chromium from solution. This was supported by energy dispersive spectroscopy (EDS) analysis.<p>The coarsening of carbides correlates with the decrease in creep resistance of the material and it is likely that the growth of precipitates and recovery of the microstructure causes the entry of the steel into third stage creep.

Gabón es un país de Africa ecuatorial con uno de los mayores consumos de carne de caza del continente. Los roedores silvestres se encuentran entre las especies más apreciadas y con mayor valor comercial. Con el objetivo de estudiar la viabilidad técnica de cría de aulácodos (Thryonomys swinderianus) en Gabón, se estableció una granja demostrativa a partir de animales importados de Benin. Los resultados zootécnicos no presentaron grandes diferencias respecto a los parámetros descritos en Benin. En 19 meses, se obtuvieron 130 camadas de 4,06 crías /parto, 1,86 partos/hembra y 6,77 crías destetadas/hembra /año. A partir de 1995, se inició la fase de difusión de tecnología a criadores locales. En las granjas, se observó una prolificidad elevada (4,47 crías / camada), pero una productividad numérica baja (2,48 destetados /hembra /año; n=90 partos). La mortalidad global y la mortalidad al destete fueron elevadas (22 y 31% ; n=79 partos). Los resultados demuestran que la cría del aulácodo es técnicamente viable a pesar de que existe un amplio margen de mejora entre los criadores y dificultades de asimilación de las técnicas. A pesar de que esta producción aun no llega a sustituir el enorme volumen de carne de caza comercial, presenta un buen potencial para la producción de proteína animal en áreas periurbanas de Gabón y para la generación de ingresos para el criador.También se estudió la morbilidad y mortalidad en la granja experimental de Libreville durante un periodo de 21 meses. El 28% de los casos de mortalidad se produjeron en animales jóvenes, el 42% en subadultos y el 28% en adultos La principal causa de mortalidad fueron los traumatismos, (29% de los casos), seguidos septicemia (12%), patologia respiratoria (10%). El seguimiento realizado permitió identificar algunas diferencias respecto otros estudios y establecer las primeras referencias sobre la patología de este animal en África Central. También permitió describir casos de neoplasia identificados por primera vez en esta especie. Por ultimo, se investigo el potencial productivo de Atherurus africanus mediante un analisis de 22 aparatos reproductores de hembras silvestres. Todas las hembras gestantes presentaron un solo feto u embrión y el numero de cuerpos luteos (CL) fue de 19,9 ± 5,4 (diámetro = 1709 ± 421 µm), incluyendo un CL de gestacion (diámetro medio = 4821 µm ± 1364 µm ). La media de tejido luteal activo fue elevada (115,6 mm3). Los resultados confirman que el ateruro salvaje es también una especie mono-embrionica, pero poliovular, sugiriendo una importante mortalidad ovocitaria o embrionaria en la cual se pierde mas del 95% del material biológico. Esto sugiere que el ateruro necesita grandes cantidades de progesterona para mantener la gestación. También, evidencia la baja capacidad reproductiva de la especie. / Gabon is an equatorial country, with one of the highest bushmeat consumption in Africa. The most favourite and commercially valuable species include wild rodents.With the aim to study the technical feasibility of cane rat (Thryonomys swinderianus) farming in Gabon, a demonstrative farm was established in the outskirts of Libreville with animals adapted to captivity. Among 130 litters, we obtained 4,06±1 young/litter, 1,86 litters/female and 6,77 weaned animals/female.Since 1995, an extension programme among local farmers was initiated. A survey in 1998, allowed the record of a high mortality (global, 19% and pre-weaning, 31%) but reproduction parameters (4,47 young/litter) comparable to those obtained in the experimental farm. Numeric productivity was 2,48 weaned/female/year. This results suggest that cane rat farming in Gabon is feasible also at a farmer's level. However, there is a large margin of improvement due to some difficulties in assimilation of animal husbandry techniques. Despite a low level of exploitation, cane rat farming has the potential to provide an alternative source of protein to commercial hunting and a substantial source of income for the farmer living in peri-urban areas.The causes of morbidity and mortality of farmed cane rats in Gabon were studied during 21 months through the survey of 94 postmortem examinations of 546 animals. Most of the cases occurred in subadults (42%), while non weaned young and adults were equally represented with 28% of the cases. Average monthly mortality was 2 ,5%. The main cause of mortality identified was trauma (29% of the sample), followed by septicaemia (12%) and respiratory problems (10%). Fifteen percent of cases were represented by digestive, urinary and reproductive disorders and 3% to other causes. No diagnosis could be reached in 28% of cases.In order to assess the prolificity of Atherurus africanus in the wild, 22 female carcasses were obtained from markets in Libreville during 2 years. Reproductive tracts were examined for the presence of embryos or foetuses. The ovaries were histologically examined. Morphology and constituent cell types of the ovaries were similar to those described for other hystricognath rodents. All pregnant females had only one embryo or foetus and 20±5 cyclic corpora lutea (CL), including one CL of pregnancy at least 2,8 times larger in diameter and 9±7 accessory CL. The mean number of antral follicles in adult females was 25±10. The study confirms that the brush-tailed porcupine is a mono-embryonic but polyovular species, suggesting important ovum mortality. This unusual reproductive feature in mammal species gives this rodent a low reproductive productivity which compromises the cost effectiveness of its captive breeding. Moreover, this species could be more susceptible to the effects of hunting than generally thought.

Aquesta tesi ha estudiat la seroprevalença de Neospora caninum i els factors de risc que la afecten en bovins d'aptitud càrnia a Andorra. S'ha avaluat els nivells d'anticossos de N. caninum mitjançant la tècnica d'ELISA considerant mostres de 1758 animals majors de 6 mesos d'edat, pertanyents a 26 explotacions. Gairebé el 85% de les 26 explotacions estudiades han estat exposades a N. caninum amb seroprevalença mitjana d'anticossos a les explotacions 7.4%. L'edat, les diferents pastures comunals i la raça, van ser els factors de risc que afecten la seroprevalença de la infecció al Principat. Els resultats suggereixen que la localització de les zones de pastura podrien potenciar la transmissió horitzontal d'aquest paràsit i que algunes races són més resistents a la infecció per N. caninum que d'altres. / The present PhD presents the results of a serological survey performed to analyze Neospora caninum seroprevalence and risk factors affecting seroprevalence in beef cattle in Andorra were investigated. Antibodies to N. Caninum were evaluated by ELISA performed on a yearly basis in 1,758 animals older than 6 mo, belonging to 26 herds. Almost 85% of the analyzed herds had at least one positive animal. Mean herd seroprevalence of antibodies to N. Caninum was 7.4%. Age, summer grazing area of the herds and breed emerged as the main risk factors affecting seroprevalence of N. Caninum infection in Andorra. The results suggest that the particular grazing location could promote the horizontal transmission of this parasite and certain breeds are less susceptible to N. Caninum infection than others.

El objetivo de esta tesis ha sido aportar información básica sobre el modo de acción de los enzimas carbohidrasas sobre los cereales viscosos o raciones convencionales no viscosas de maíz y soja. Partiendo de estos mecanismos, hemos valorado sus efectos sobre los parámetros productivos y digestivos en los pollos en crecimiento. En particular, en el caso de los cereales blancos (cebada y trigo) estudiamos la efectividad de b-glucanasas y arabinoxilanasas sobre los resultados de producción (consumo de alimento, ganancia media diaria) y digestibilidad de la ración en pollos en crecimiento; y los posibles mecanismos involucrados, como la cinética de tránsito y viscosidad de la digesta. Para alcanzar este objetivo se realizaron 2 ensayos experimentales. En el primero de ellos se utilizaron pollitos sexados machos que recibieron 4 raciones experimentales basadas en un 44% de cebada + trigo (2 x 2; con o sin enzimas, con o sin 2% de sepiolita) durante un periodo experimental de 36 días. Se realizaron dos balances de digestibilidad de la MO, PB y MG establecidos entre los días 21-22 y 41-42 de edad. Los resultados relativos a este experimento muestran que la suplementación de enzimas mejoró la ganancia media diaria de los animales y la eficiencia de conversión del alimento, sobre todo durante la primera fase de crecimiento (14%, P<0.001 y 10%, P<0.001; respectivamente). Las mejoras de los resultados productivos fueron fundamentalmente explicadas por una mejora significativa de la digestión y la retención de los componentes de la materia orgánica (5.6 up y 1.7 up.,), y en especial de la fracción lipídica (13 up., y 3.5 up.) en el día 22º y 42º, respectivamente. Teniendo en cuenta los resultados productivos obtenidos durante este primer ensayo, se planteó un segundo experimento en un diseño similar con el objetivo de caracterizar los posibles mecanismos determinantes de los resultados productivos. Entre los aspectos contemplados, se estudió i/ el ritmo de tránsito de la digesta (estimados a partir de la excreción fecal de un marcador indigestible o a partir de su cuantificación en el tracto digestivo de los animales en condiciones de equilibrio dinámico) y ii/ la viscosidad de la digesta del contenido del yeyuno e íleon.Los resultados productivos fueron similares a los del primer ensayo. No se observaron diferencias significativas en el consumo de alimento, aunque con la suplementación enzimática se incrementaron los ritmos de crecimiento (+5%, P<0.05), y se mejoraron los índices de conversión de la dieta (7%, P<0.01). Se observo una mejora en la digestión durante el día 21º de todas las fracciones de la MO (PB, 6 u.p., P<0.001; MG, 6 u.p., P<0.01 y carbohidratos, 2.5 up., P<0.05) y en consecuencia de la concentración energética de la ración (EMAn: 5.4% de 3110 a 3280 Kcal/ kg MS alimento). La suplementación enzimática redujo significativamente la viscosidad relativa al agua determinada en el intestino (yeyuno e íleon) y los tiempos de retención (MRT) de la digesta en el tracto digestivo.La suplementación enzimática en la alimentación de los broilers en la actualidad consiste mayoritariamente en la inclusión de b-glucanasas y arabinoxilanasas en raciones con cereales «viscosos». Sin embargo, recientemente, numerosas expectativas se están incorporando como son la búsqueda de estrategias enzimáticas dirigidas a mejorar el valor nutritivo de las leguminosas en general y la torta de soja en particular. En esta línea, nos planteamos como objetivo caracterizar «in vitro» e «in vivo» la efectividad de diferentes enzimas carbohidrasas sobre la digestión de los polisacáridos solubles e insolubles de la torta de soja.Para atender estos objetivos, se planteó un primer ensayo de caracterización de los carbohidratos de la soja (cotiledones y cascarilla). El fraccionamiento (soluble e insoluble en agua) de la cascarilla de la soja mostró la existencia de una estructura insoluble mayoritariamente constituida por celulosa (b-1,4-D-glucosa), mientras que la fracción soluble contiene una mayor proporción de manosa y galactosa (posiblemente b-mananos del tipo galacto- y glucómananos). En cuanto a los cotiledones, su fraccionamiento mostró la existencia de estructuras complejas compuestas por un entramado de pectinas, hemicelulosas y celulosa. La incubación "in vitro" con enzimas de actividad pectinasa, xilanasa y celulasa mostró un bajo porcentaje de hidrólisis de los carbohidratos, aunque se incrementó (hasta un 20% de liberación de monosacáridos) tras la extracción de diferentes componentes del entramado de pared vegetal.Puesto que es conocido el efecto del tostado de la soja sobre la solubilidad y la digestibilidad de la proteína, se planteó un segundo ensayo con el objetivo de establecer la influencia de un tostado suave o intenso sobre la eficiencia enzimática "in vitro", especialmente de la proteasa y diferentes carbohidrasas. Efectivamente, el tostado provocó un descenso gradual en la solubilidad tanto de la fracción proteica como de los carbohidratos, lo que sugiere cambios estructurales del entramado de carbohidratos en su relación con la proteína. Ambas fracciones, las solubles e insolubles en agua fueron utilizadas como sustrato susceptible de hidrólisis por los enzimas carbohidrasas (pectinasa, xilanasa, mananasa y celúlasa) en combinación o no con proteasa. La incubación de los substratos solubles con enzimas carbohidrasas (en especial, celulasa y pectinasa) redujo la proporción de rafinosa y estaquiosa. Actividad que no fue evidenciada con la mananasa en su combinación con proteasa. La incubación con carbohidrasas de las fracciones no extractables con agua liberó una baja cantidad de monosacáridos, aunque se incrementó sinérgicamente con la inclusión de proteasa. Sin embargo, la posible efectividad de los enzimas "in vivo" esta condicionada por aspectos asociados al animal, que no pueden ser simulados "in vitro". Por ello, decidimos iniciar el desarrollo de pruebas de crecimiento en broilers en las que estudiar las posibles mejoras productivas y digestivas asociadas a la inclusión de enzimas de pared vegetal. En concreto, nos planteamos probar, en un primer ensayo, el efecto de incorporar a una ración base de maíz-soja una mananasa (a dos niveles de inclusión), asociado o no con proteasa. Para ello, se planteó un experimento similar al descrito para las b-glucanasas y arabinoxilanasas. La suplementación con enzimas no provocó modificaciones significativas de los resultados productivos de los animales o de la digestibilidad de la ración. Sin embargo, la incorporación de mananasa a la dieta redujo significativamente la proliferación microbiana en íleon (medida como concentración de bases puricas) durante la primera fase de crecimiento de los pollitos. Aunque la experiencia fue realizada en jaulas, y no se observaron diferencias en productividad, nos planteamos como interesante valorar en el futuro las repercusiones productivas y sanitarias que este tipo de modificaciones microbianas pueden tener, especialmente en condiciones prácticas de producción. / The aim of this thesis is to obtain basic information on the activity of carbohydrase enzymes over viscous cereals or conventional no viscous diets based on corn and soybean meal. The effects of enzymes supplementation in broiler chickens productive and digestive parameters will be also evaluated. In particular, in the case of the white cereals (barley and wheat), we have studied initially the effectiveness of b-glucanase and arabinoxylanase on the productive performances (Feed intake, bodyweight gain) and nutrient digestion in growing chicks; and the possible mechanisms involved, like the digesta kinetics and viscosity. Two experimental trials are presented. Male chickens received 4 experimental diets based on 44% of barley + wheat (2 x 2; with or without enzymes, with or without 2% of sepiolite) during an experimental period of 36 days. Two balances of organic matter (OM), crude protein (CP) and fat (EE) were carried out on days 21-22 and 41-42 of age. The enzymes supplementation improved the daily weight gain of the animals and the food: gain ratios, mainly during the first phase (14%, P<0.001 and 10%, P<0.001; respectively). Productive results were simultaneous to significant increases of the whole-tract digestibility and retention of organic components, (5.6 and 1.7 percent units), especially the fatty fraction (13 and 3.5 percent units) on day 22 and 42, respectively.The second experiment aimed to characterise the possible mechanisms involved. They were studied i/ the digesta mean retention time (MRT estimated from the faecal excretion of an indigestible marker or from its quantification in the animal digestive tract in steady state conditions) and ii / the jejunum and ileum digesta viscosity.Productive results were similar to those of the first trial. Although, not significant differences were observed in food consumption, enzymes supplementation increased growth rates (+5%, P<0.05), and improved the FCR (7%, P<0.01). It was also observed a significant increase of the OM digestibility (CP, 6 percent units, P<0.001; EE, 6 percent units, P<0.05 and carbohydrates, 2.5 percent units, P<0.05) and metabolizable energy (EMAn: 5.4% from 3110 to 3280 Kcal / kg DM food). The enzymatic suplementación significantly reduced intestinal digesta viscosity (jejunum and ileum) and digesta MRT in the digestive tract.Enzymatic supplementation in broilers feeding has expanded mainly as the b-glucanase and arabinoxylanase inclusion in «viscous» cereal diets. However, recently numerous expectations are being incorporated in poultry feeding, addressed by the search of enzymatic strategies to improve the nutritive value of leguminous in general, and soybean meal in particular. In this line, we planed to characterise «in vitro» and «in vivo» the effectiveness of different carbohydrase enzymes on the digestion of soluble and insoluble soybean meal polysaccharides.We designed a first trial to characterise soybean meal carbohydrates (cotyledons and hulls). Fractionation (Water soluble and Water insoluble) of soybean hulls showed the existence of an insoluble structure mostly constituted by cellulose (b-1,4-D-glucose), while the soluble fraction contains a higher proportion of mannose and galactose (possibly b-manans of galacto- and gluco-manans type). Fractionation of cotyledons showed the existence of complex structures composed by a matrix of pectins, hemicellulose and cellulose. The "in vitro" incubation with pectinase, xylanase and cellulase enzymes released a low percentage of monosaccharides, but increased (until 20%) after cell wall fractionation.Knowing the effect of toasting on SBM protein solubility and digestibility, the second experiment aimed to establish relationships between toasting (low and severe) and the "in vitro" enzymatic efficiency, especially of protease and different carbohydases. Effectively, toasting soybean caused gradual decreases in protein and carbohydrate solubility, indicating structural changes of the carbohydrate matrix in their relationship with proteins. Both, water-soluble and water-insoluble fractions were incubated with carbohydrases (pectinase, xylanase, mannanasa and cellulase) in combination or not with protease. Incubation of the soluble substrates with carbohydrases (especially cellulase and pectinase) reduced raffinose and stachyose. Similar results were not observed with mannanase. Incubations of the water-insoluble fractions released a low monosaccharide quantity, but sinergycally increased with the simultaneous incubation with protease. However other aspects that cannot be simulated "in vitro" will affect efficiency of enzymes "in vivo" associated to the animal gastro-intestinal conditions. Then, we decided to check in "in vivo" trials the possibility of improving productive and digestive performances in broilers. In a first trial, we proved the effects of incorporating to a corn-soybean meal diet a mannanase enzyme (at two inclusion levels) associated or not with protease. Experimental design was similar to that described above for the b-glucanase and arabinoxylanase trial. Enzymes supplementation didn't cause significant modifications on productive or digestive results. However, mannanase incorporation significantly reduced the ileum microbial content (measured as purine bases concentration, during the first phase of chicken's growth). Although the experience was carried out in cages, and the not differences in the productivity observed, we think interesting to evaluate the productive and health impact of this effect on the microbial colonisation of small intestine digesta, especially under practical conditions.

1. Introducción y Material y métodosAprovechando la aparición de una nueva tecnología (el suministrador automático de consumo alimentario) y motivados por la disminución del apetito (consumo diario de alimento) observado en la especie porcina durante los últimos años, decidimos explorar el comportamiento alimentario del cerdo para después relacionarlo con otros factores. Algunos de los objetivos que nos propusimos estudiar fueron: la influencia de la luz sobre la conducta circadiana alimentaria, las relaciones internas (correlaciones) entre los parámetros de comportamiento alimentario, el patrón alimentario de cada raza, la influencia del gen del halotano y de la jerarquía social sobre el comportamiento alimentario y la relación entre la conducta alimentaria y la productividad.En el Centre de Control Porcí de Monells (IRTA) analizamos 205 cerdos machos enteros de cuatro razas distintas: 47 de raza Duroc, 60 de raza Landrace, 69 de raza Large White y 29 de raza Piétrain. Realizamos dos experimentos de 50 días, uno en otoño de 1995 y otro en la primavera de 1996. La alimentación fue ad libitum y el ciclo de iluminación fue el natural. Los animales fueron distribuidos en corrales de 12,85 m2. Cada corral contenía entre 12 y 14 cerdos de una misma raza. El registro de la información se hizo por medio de los suministradores automáticos de consumo alimentario IVOG -station. Cada corral disponía de un único suministrador, cuyo diseño permitía la competencia entre los cerdos en el momento de visitar el comedero. A partir de la información recogida por el suministrador y después de realizar un proceso de filtrado y depuración de los datos se construyeron los parámetros alimentarios: consumo de alimento diario (CAD = g), consumo de alimento por visita o tamaño de la visita (CAV = g), tiempo de ingestión diario (TID = min), tiempo de ingestión por visita o duración de la visita (TIV = min), número de visitas diarias o frecuencia de visitas (NVD) y velocidad de ingestión diaria (VID = g/min).El gen del halotano se identificó a partir de muestras de sangre de cada animal por medio del test del DNA basado en la multiplicación y restricción selectiva del gen "ryanodine", cuya mutación es la causa del síndrome del estrés porcino. El estudio de la jerarquía se realizó únicamente en la raza Large White y consistió en la filmación de los animales con la posterior observación de las interacciones antagónicas entre pares de animales con el fin de establecer el grado de dominancia de cada animal. En cada corral se distinguió a los animales en dos categorías: a los de mayor rango jerárquico se les llamó dominantes y a los de menor, sumisos.2. Resultados más destacados2.1. Influencia de la luz sobre la conducta alimentariaObservamos que la conducta circadiana del cerdo fue sensible a la luz: a) la salida y la puesta del sol desencadenaron picos de consumo. b) En la estación de mayor horario solar (primavera) se amplió también el nivel de actividad alimentaria: en primavera los animales dedicaron tres horas más que en otoño a la actividad máxima de ingestión. c) Esta ampliación del horario solar pudo ser la causa de que en primavera apareciera un tercer pico de consumo, alrededor de las 13.00 horas. A los animales les dio más tiempo para expresar otro pico de consumo. d) Los cerdos presentaron actividad alimentaria durante las 24 horas del día pero fue mucho mayor durante las horas de luz que durante la noche.2.2. Relaciones internas entre los parámetros alimentarios1ª relación: los dos parámetros alimentarios de mayor correlación con el apetito (consumo diario) fueron el tamaño (r entre 0,65 y 0,28) y la velocidad (r entre 0,59 y 0,32). 2ª relación: el consumo y la velocidad se relacionaron positivamente (r entre 0,59 y 0,32) y el tiempo y la velocidad presentaron relación negativa (r entre --0,79 y -0,67)-. 3ª relación: existió relación positiva entre la duración y el tiempo diario (r entre 0,5 y 0,28), y entre el tamaño y el consumo diario (r entre 0,65 y 0,28). 4ª relación: la frecuencia siempre presentó relación inversa con el tamaño (r entre -0,84 y -0,77) y con la duración (r entre -0,86 y -0,72), y estos dos parámetros se relacionaron entre sí de forma estrecha y positiva (r entre 0,90 y 0,87).2.3. El patrón alimentario de cada razaEl estudio del efecto raza sobre los parámetros alimentarios nos permitió agrupar las razas de la siguiente manera: respecto a la velocidad y al tiempo diario de ingestión observamos que las razas Landrace y Large White tuvieron mayor velocidad de ingestión y requirieron menor tiempo de ingestión que las otras dos. A estas razas las llamamos rápidas y a las otras, lentas. Respecto a la frecuencia y al tamaño, obtuvimos que las razas Duroc y Landrace visitaron menos veces al día el comedero pero aprovecharon más cada visita (mayor tamaño). A estas dos razas las denominamos glotonas mientras que a las razas Large White y Piétrain, que van muchas veces al comedero pero que comen poco en cada visita, las llamamos mordisqueadoras. La combinación de los diferentes caracteres descritos nos aporta la descripción del patrón alimentario propio de cada raza. Así tenemos que la raza Duroc fue glotona lenta, la Landrace fue glotona rápida, la Large White fue mordisqueadora rápida y la raza Piétrain fue mordisqueadora lenta.2.4. La influencia del gen halotano sobre el comportamiento alimentarioLos animales sensibles al estrés porcino (genotipo halotano recesivo) presentaron mayor tiempo de ingestión diaria y menor velocidad que los animales homocigotos dominantes o heterocigotos. Así pues, el genotipo halotano recesivo afectó al comportamiento alimentario de manera significativa. Suponemos que estos animales -que son los más nerviosos- interrumpen con mayor frecuencia sus comidas, perjudicando la velocidad y requiriendo mayor tiempo de ingestión para compensar la baja velocidad.2.5. La influencia de la jerarquía social sobre el comportamiento alimentarioLos cerdos dominantes presentaron mayor consumo y frecuencia, y menor tamaño y duración. Por tanto, podemos concluir que la jerarquía afectó a los parámetros alimentarios a pesar de que el sistema de alimentación fue ad libitum. Suponemos que el hecho de que el suministrador automático de consumo alimentario presente un comedero único por corral provoca una restricción virtual de alimento en los animales sumisos, perjudicado su consumo diario.2.6. La relación entre el comportamiento alimentario y la productividadLos parámetros alimentarios que presentaron mayor relación con el crecimiento fueron, de más a menos, el consumo diario (r entre 0,93 y 0,80), el tamaño (r entre 0,54 y 0,28) y la velocidad (r entre 0,43 y 0,32). Por tanto, los parámetros alimentarios que tuvieron mayor relación con el consumo diario son los que, junto con éste, presentaron mayor correlación con el crecimiento. / 1. Introduction, materials and methodsTaking advantage of the appearance of a new technology (automatic food supplier) and motivated by the loss of appetite (daily food intake) noticed in the pig species during the last few years, we decided to investigate the feeding behaviour of the pig, and then relate it to with other factors. Some of the facts we decided to study were: the influence of light on circadian feeding behaviour, internal relations (correlation) between parameters of feeding behaviour, feeding pattern of each breed, influence of the halothane gene and social hierarchy on feeding behaviour, and the relationship between feeding behaviour and productivity.In the "Centre de Control Porcí de Monells (IRTA)" we studied 205 pigs (boars) of four different breeds: 47 Duroc, 60 Landrace, 69 Large White and 29 of the Pietrain breed. We performed two experiments lasting 50 days each, autumn 1995 and in spring 1996. The feeding was ad libitum and the cycle of light was natural. Animals were distributed in stiles of 12.85 m2. Each stile had between 12 and 14 pigs of the same breed. Information was recorded by the automatic food supplier IVOG -station. Each stile had only one supplier, whose design allowed competition between pigs trying to visit the feeder. From information recorded by the supplier, and subsequently sorted and filtered, the following parameters were constructed: daily food intake (DFI = g), food intake per visit (FIV = g), duration of daily food intake (DDFI = min), duration of food intake per visit (DFIV = min), number of daily visits or frequency of visits (NDV) and rate of daily food intake (RDFI = g/min).The halothane gene was identified from blood samples of each animal using a DNA test which consisted in the multiplication and selective restriction of the "ryanodine" gene, whose mutation is the cause of pig stress syndrome. The study of hierarchy was performed only with the Large White breed and consisted in filming the animals in order to observe any antagonistic interactions between pairs of animals, and later establish the degree of dominance exhibited by each one. In each stile animals were divided into two categories: animals with the greater hierarchical range were classified as dominant and animals with smaller ones, submissive.2. More important results 2.1. Influence of light on feeding behaviourWe observed that the circadian behaviour of the pigs was sensitive to light: a) Daybreak and sunset excited peaks of food intake. b) During the season with more hours of light (spring) the food intake activity level was greater as well: in spring the maximum feeding activity was tree hours longer than in Autumn. c) This increase in solar hours could be the cause of a third feeding peak which appeared in Spring around 13.00 h: the animal had more time during which to exhibit another feeding peak. d) The pigs exhibited feeding activity during the 24 hours of the day but the food intake level was much higher during the hours of light, than at night.2.2. Internal relationships between feeding parameters1st relationship: the two feeding parameters which showed a greater correlation with appetite (daily food intake) were the food intake per visit (r between 0.65 and 0.28) and the rate of daily food intake (r between 0.59 and 0.32). 2nd relationship: the total daily food intake and the rate of daily food intake exhibited a positive correlation (r between 0.59 and 0.32), while the duration of daily food intake and the rate of daily food intake had a negative correlation (r between -0.79 and -0.67). 3rd relationship: existed positive correlation between the duration of food intake per visit and the duration of daily food intake (r between 0.50 and 0.28), as well as between the food intake per visit and the daily food intake (r between 0.65 and 0.28). 4th relationship: frequency always exhibited an inverse relationship with food intake per visit (r between -0.84 and -0.77) as well as with the duration of food intake per visit (r between -0.86 and -0.72), while these latter two parameters showed a close and positive correlation with each other (r between 0.90 and 0.87).2.3. Feeding pattern of each breedThe study of the breed effect on food intake parameters allowed to group the breeds in the following way: with respect to the rate of daily food intake and the duration of daily food intake we observed that Landrace and Large White breeds had a greater rate of daily food intake and needed less duration of daily food intake than the two others. The Landrace and Large White breeds were dominated "speedy" while the other two were called "slow-coach". With respect to frequency and food intake per visit, results showed that the Duroc and Landrace breeds visited the feeder fewer times a day but consumed more each time (higher food intake per visit). These two breeds were referred as "meal eaters" while that Large White and Pietrain breeds, which visited the feeder many times but ate little each time, were called "nibblers". The combination of the different behaviours just described allowed a description of each breed's feeding pattern. Thus, we found the Durocs breed to be slow-eaters, the Landraces speedy-meal eaters, the Large Whites speedy-nibblers and the Pietrais slow-nibblers.2.4. Influence of the halothane gene on feeding behaviourThe PSS animals (recessive halothane genotype) had a higher duration of daily food intake and a lower rate of daily food intake than the dominant homozygotes or the heterozygotes. Thus, the recessive halothane genotype affected feeding behaviour in a significant way. We suppose these animals -the most nervous of the lot- interrupted their meals more frequently, thus adversely affecting their feeding rate and requiring more feeding time to compensate for their low rate of daily food intake.2.5. Influence of social hierarchy on feeding behaviourThe dominant pigs exhibited a higher level of daily food intake and frequency, as well as a lower level of food intake per visit and duration of food intake per visit. Therefore, we can conclude that hierarchy affected feeding behaviour parameters although the feeding system was ad libitum. We suppose that the fact that the automatic food supplier has only a single access to feeder per stile provokes a virtual restriction of food intake on submissive, adversely affecting their daily food intake.2.6 Relationship between feeding behaviour and productivityThe feeding parameters which had a close relationship with daily growth were, in descending order, daily food intake (r between 0.93 and 0.80), food intake per visit (r between 0.54 and 0.28) and rate of daily food intake (r between 0.43 and 0.32). Therefore, the feeding parameters that were more closely related to daily food intake were those which, along with the latter, exhibited a higher correlation with daily growth.

El objetivo de la Tesis doctoral fue valorar la interacción entre el grado de poliinsaturación y el nivel de a-tocoferol dietéticos sobre el valor nutritivo y la estabilidad oxidativa de la carne de pollo. Así mismo, también se pretendió estudiar la responsabilidad de la síntesis endógena sobre el depósito de ácidos grasos (AG) en la misma. Para ello se diseñaron dos experimentos.Ambos experimentos se basaron en niveles crecientes de acetato de a-tocoferol (0, 100, 200 y 400 mg/kg) y de ácidos grasos poliinsaturados (AGPI) dietéticos. En el primer estudio el gradiente de poliinsaturación dietético se consiguió reemplazando una grasa saturada (sebo) por una mezcla de aceites poliinsaturados (linaza y pescado) suplementados a un nivel constante de 9%. En el segundo estudio este gradiente se consiguió mediante la adición de niveles crecientes de la fuente de grasa poliinsaturada (2, 4, 6 y 8%). Para la realización de cada estudio experimental se utilizaron 192 broilers hembras. En relación a la composición de AG, a medida que aumentó el grado de poliinsaturación dietético, el contenido y proporción de los AGPI en muslo y pechuga aumentó exponencialmente, mientras que el contenido y la proporción de ácidos grasos saturados (AGS) y monoinsaturados (AGMI) se redujo linealmente. Además, el consumo de una dieta con elevados niveles de AGS y AGMI dio lugar a que la proporción de AGPI se deposite a un ritmo fraccional superior que al consumir raciones con un mínimo contenido de estos AG.Por otro lado, la concentración de AGS y AGMI en los tejidos de las aves dependió de la aportación de la dieta y de la síntesis endógena. Así, al aumentar el nivel de grasa del pienso, de 0 a 10%, el depósito de AGS procedentes de la síntesis endógena disminuyó de 37,8 a 17,8% en el muslo y de 39,2 a 23,3% en la pechuga. De forma similar el depósito de AGMI procedentes de la síntesis endógena disminuyó de 48,5 a 8,0% en el muslo y de 42,6 a 9,8% en la pechuga. Por otro lado, la suplementación con acetato de a-tocoferol a dosis inferiores o iguales a 400 mg/kg, no afectó al contenido de AG del muslo y de la pechuga.La concentración tisular de a-tocoferol en el muslo fue 1,8-2,3 veces superior a la pechuga. En ambos tejidos dicha concentración fue directamente proporcional al consumo del mismo, e inversamente proporcional al consumo de AGPI. La reducción del depósito de a-tocoferol en los tejidos de las aves por un aumento del grado de poliinsaturación fue más elevada en aquellos tejidos de los pollos alimentados con elevadas dosis de acetato de a-tocoferol. La cantidad de a-tocoferol necesaria para conseguir un nivel de enriquecimiento en la carne de pollo de 40 mg/kg varía en función del grado de poliinsaturación dietético, por cada unidad de aumento de AGPI en la ración se necesita incrementar 3-4 mg a-tocoferol para contenidos dietéticos de AGPI bajos (15-20 g/kg) y 12-23 mg a-tocoferol para contenidos altos (superior a 55-60 g de AGPI/kg).En general, los procesos de cocción y posterior conservación en refrigeración del muslo de pollo favorecieron los procesos de oxidación de la fracción lipídica. Además, la susceptibilidad a la oxidación de la carne de pollo aumenta proporcionalmente a su contenido en AGPI y se reduce a medida que aumenta su concentración en a-tocoferol. Además, el efecto antioxidante del a-tocoferol presentó una saturación. En este sentido, la estabilidad oxidativa de la carne de pollo no se vio afectada por un aumento en el nivel de a-tocoferol dietético de 200 a 400 mg/kg. / The objective of the present study was, firstly, to determine the influence of diets containing increasing levels of polyunsaturated fatty acids (PUFA) and different levels of supplementation with a-tocopheryl acetate on the nutritive value and oxidative stability in marketable raw and cooked chicken meat. The second objective was to estimate the amount of fat deposited in marketable chicken meat coming from endogenous synthesis. Therefore, two experiments were carried out:Both experiments were based on 4 levels of dietary supplementation with a-tocopheryl acetate (0, 100, 200 and 400mg/kg) and 4 levels of dietary PUFA. The gradient of dietary PUFA was achieved, in first experiment, by blending different quantities of tallow, linseed oil, and fish oil, keeping the added fat content of the diets constant (9%); and in second experiment, by increasing of the level of dietary polyunsaturated oils (2, 4, 6 and 8% of linseed and fish oil). One hundred and ninety-two female broiler chickens were used.Increasing PUFA content of the diet increased exponentially the content and proportion of PUFA in thigh and breast meat, and decreased linearly their monounsaturated fatty acids (MUFA) and saturated fatty acids (SFA) content. Furthermore, chickens that intake diets with higher levels of SFA and MUFA showed a higher fractional rate in PUFA deposit than those intake diets with a lower content of these FA.Concentration of MUFA and SFA in chicken tissues depended on FA coming from diet and from endogenous synthesis. Therefore, increasing the level of dietary fat from 0 to 10%, the SFA deposit coming from endogenous synthesis decreased from 37.8 to 17.8% in thigh and from 39.2 to 23.3% in breast. Similarly, MUFA deposit coming from endogenous synthesis decreased from 48.5 to 8.0% in thigh and from 42.6 to 9.8% in breast.On the other side, the effect of supplementing broiler diets with a-tocopheryl acetate up to 400 mg/kg of feed did not have any effect on thigh and breast muscle fatty acid content.a-Tocopherol concentration of thigh meat was 1.8-2.3 times higher than breast meat. The a-tocopherol content of thigh increased linearly as the intake of a-tocopherol increased, and decreased linearly as the intake of PUFA increased. Furthermore, the a-tocopherol reduction depending on dietary polyunsaturation level was higher in diets supplemented with high doses of a-tocopheryl acetate.The a-tocopherol amount necessary to achieve 40 mg/kg of enrichment in chicken meat varied with the dietary polyunsaturation level. Therefore, when the dietary PUFA (g/kg) increase 1 g was necessary to increase a-tocopherol 3-4 mg and 12-23 mg for low (15-20 g/kg) and high levels (higher than 55-60 g/kg) of dietary PUFA, respectively.In general, cooking and refrigeration of thigh meat increased its lipid oxidation. Dietary PUFA also increased susceptibility of meat to oxidation due to PUFA deposition in meat, which leads to higher oxidative pressure. Contrarily, dietary a-tocopherol acetate supplementation prevents lipid oxidation through the accumulation of the a-tocopherol in thigh meat. Furthermore, there is saturation in the antioxidant effect of a-tocopherol, that means, the response was similar for the treatments supplemented with 200 and 400 mg a-tocopheryl acetate/kg.