Modelizaci��n de la evoluci��n del dep��sito proteico en ganado porcino en el per��odo de engorde. Efecto del r��gimen alimentario, sexo y condiciones ambientalessobre la eficiencia y producci��n de residuos

Las aptitudes gen��ticas de los genotipos porcinos actuales han cambiado considerablemente durante los ��ltimos a��os. La eficiencia en la capacidad para el dep��sito de carne magra ha aumentado considerablemente. Los aportes alimentarios deben por lo tanto adaptarse a las necesidades nutricionales de dichos animales. El potencial productivo de los animales var��a en funci��n de condicionantes gen��ticos ( tipo gen��tico), fisiol��gicos ( sexo), ambientales ( T��, densidad), nutricionales ( composici��n de las dietas y tipos de dietas), sanitarios ,etc. Sus caracter��sticas productivas, y sus necesidades nutricionales, evolucionan con el tiempo ( edad y/o peso ) de forma no lineal , existiendo ��ptimos biol��gico-t��cnicos variables en cada sistema de producci��n ( granja-mercado) que determinan unos m��ximos m��rgenes econ��micos ( y/o ambientales). Dentro de cada l��nea es necesario considerar el efecto sexo . Las necesidades de un macho, una hembra o un castrado son muy distintas. Las necesidades nutricionales de los animales dependen tambi��n del peso y/o edad del cerdo de engorde. La alimentaci��n debe variar tanto en cantidad como en calidad a lo largo del engorde usando programas de alimentaci��n por fases. Esta t��cnica es especialmente interesante desde el punto de vista medioambiental ya que permite la reducci��n de la excreci��n de nitr��geno y f��sforo contribuyendo a la reducci��n de residuos por Kg. de carne.

Transferring QTL technology to the pig breeding industry (PigQTech) - a demonstration project

The aim of the project has been to demonstrate how the farm animal breeding industry can utilise gene mapping technology to accelerate genetic improvement. Previous theoretical studies had suggested that the use of marker assisted selection could potentially increase the annual improvement for quantitative traits like backfat with about 10% and for more difficult traits such as meat quality and reproduction by as much as 40-60% compared with existing technology. The work has comprised two major tasks: 1. Commercially relevant populations have been screened for segregation at QTLs identified in experimental populations. The aim has been to establish optimal strategies for QTL detection in commercial pig populations and the extent to which QTLs explaining major phenotypic differences between divergent lines used in experimental studies also explain quantitative variation within commercial lines. The results are important for specifying future strategies for finding economically valuable QTLs. 2. Marker assisted backcrossing has been used to demonstrate how a QTL allele can be introgressed from one breed to another. The work has focused on the major fatness QTL on pig chromosome 4 previously identified in a wild pig/Large White intercross. The end result was not designed to be a commercially viable product in its own right, but the process has validated a number of points of major importance for the exploitation of QTLs in livestock.

Alleviating abiotic and biotic soil constraints by combining Arbuscular Mycorrhizal Fungi with banana and plantain micropropagation systems

The objectives of Participant 4 were: - Establishment and maintenance of a representative collection of AM fungal species in vivo on trap plant cultures. - Study of the effects of early mycorrhizal inoculation in the growth and health of in vitro plantlets and their subsequent behaviour in the nursery. - Effect of the mycorrhization of in vitro produced bananas and plantains on plant growth and health, under biotic stress conditions (nematode and fungi)

Renovaci��n y mejora varietal de frutales de hueso

El melocotonero (Prunus persica (L.) Batsch) es un cultivo de importancia creciente en Espa��a, particularmente para producci��n temprana en las regiones meridionales de la Pen��nsula. Adem��s tiene una elevado ritmo de sustituci��n de variedades. Solamente entre los a��os 1990-96 se comercializaron en el mundo alrededor de 500 nuevos cultivares (Fideghelli et al. 1998). El valor de las nuevas obtenciones es muy elevado, por lo que existe tambi��n un gran inter��s en su protecci��n por parte de los mejoradores, y en el control de su identidad por viveristas o agricultores. La identificaci��n varietal con datos sobre la morfolog��a y fisiolog��a de los frutales se realiza en ensayos de campo que requieren largo tiempo, generalmente a��os, de observaci��n. Estos procesos son demasiado lentos para aplicaciones como el control de identidad en vivero o para la protecci��n de los derechos de obtentor. Los marcadores moleculares, basados en la variabilidad del ADN, pueden detectarse en cualquier momento del desarrollo de la planta, y en diferentes tejidos, permitiendo establecer en pocos d��as un perfil ��nico para cada variedad. El melocotonero es una de las especies menos variables del g��nero Prunus (Byrne, 1990). Ello se debe a su sistema de autocompatibilidad que permite la autofecundaci��n, lo que probablemente ha causado una importante erosi��n de su variabilidad gen��tica especialmente desde el uso de las t��cnicas modernas de mejora gen��tica. La baja variabilidad de este cultivo significa que los 2 marcadores que deben ser utilizados para su identificaci��n han de buscarse entre los de mayor polimorfismo, ya que el uso de marcadores de buena calidad pero poco polim��rficos no permite el objetivo de la caracterizaci��n individual de cada genotipo (Messeguer et al., 1986).

Seguridad alimentaria en productos c��rnicos: aplicaci��n de sistemas emergentes de conservaci��n y evaluaci��n de pat��genos mediante el desarrollo de nuevas t��cnicas moleculares

Durante el desarrollo del proyecto se ha podido constatar la relevancia de la utilizaci��n de m��todos alternativos de conservaci��n tales como la alta presi��n hidrost��tica; as�� como el efecto a��adido de los bioconservantes naturales aplicados en masa o envasado activo en la seguridad alimentaria de los productos c��rnicos curado cocidos. Asimismo el desarrollo y la identificaci��n, cuantificaci��n de los pat��genos alimentarios a estudio (Listeria monocytogenes y Salmonella spp) mediante t��cnicas de biolog��a molecular, PCR convencional, PCR cuantitativa y NASBA, adem��s de suponer un importante logro cient��fico, ha significado una enorme ventaja en los ensayos tipo ���challenge test��� tanto por rapidez en la anal��tica realizada como para la evaluaci��n simult��nea de un n��mero elevado de muestras por ensayo. Cabe destacar la importancia del NASBA en la detecci��n selectiva de c��lulas viables.

Production and carcass quality of ten beef cattle breeds of the southwest of Europe

A sample of about 70 young bulls of each of ten beef cattle breeds reared in their typical production systems has been studied regarding growth and carcass quality traits. Breeds included were Asturiana de los Valles (AV), Asturiana de la Monta��a (AM), Avile��a-Negra Ib��rica (A-NI), Bruna dels Pirineus (BP), Morucha (Mo), Pirenaica (Pi) and Retinta (Re) from Spain, and Aubrac (Au), Gasconne (Ga) and Salers (Sal) from France. There existed large differences between breeds and also within breeds. AV and Pi were the breeds with more muscle and less fat, whereas A-NI, Mo and Re were in the opposite side. BP and AM occupied an intermediate position. This allows to classify the Spanish breeds in three groups: AV and Pi would belong to the group of late maturity, A-NI, Mo and Re, would be early maturing breeds, whereas BP and AM, despite the small size of the last, will be of intermediate maturity. In the French populations, Au was the breed with the highest carcass weight and Ga exhibited the lowest. Sal occupied an intermediate position, showing the longer and thinner thigh. In a wide range of carcass weight, the general relationships among carcass traits have been confirmed. Animals with the better conformation were also the leaner and longer carcasses tended to be lowly associated with a poorer conformation and fatter carcasses. Bone content was clearly opposed to carcass conformation and muscle content and was associated with longer carcasses

Modificaciones del proceso de salado, lavado y postsalado del jam��n curado: efecto en la composici��n, estructura y flora de la superficie y en las caracter��sticas sensoriales

El objetivo de este estudio era mejorar el proceso de elaboraci��n de los productos crudos curados y del jam��n curado en particular controlando la composici��n y estructura del exterior de la pieza mediante tratamientos superficiales o con los par��metros de control de proceso. Para ello se evaluaron: - El efecto que tienen algunas substancias a��adidas sobre el desarrollo microbiol��gico superficial y la estructura. - Factores que pueden afectar a la formaci��n del encostrado superficial (composici��n superficial y condiciones ambientales). - El efecto de la adici��n de determinadas substancias y de la humedad relativa durante el reposo en la cin��tica de secado y en las caracter��sticas sensoriales del jam��n curado. Asimismo se plantearon modificaciones de los procesos tecnol��gicos que permitiesen modular algunas caracter��sticas sensoriales.

Suplementaci��n de tranquilizantes naturales en la dieta de cerdos con diferente genotipo al estr��s: sobre el bienestar animal y la calidad tecnol��gica y sensorial de la carne

El objetivo principal del proyecto era estudiar el efecto de tranquilizantes naturales sobre el bienestar de los animales y la calidad de la carne desde un punto de vista tecnol��gico y sensorial. Este objetivo se desglosaba en dos: OBJETIVO 1 ��� Evaluar la eficacia de tranquilizantes naturales (Magnesio, tript��fano) en la disminuci��n del nivel de estr��s en cerdos de tres genotipos diferentes respecto del gen Hal, homocigotos dominantes NN, o portadores (Nn y nn) en el per��odo anterior al sacrificio. OBJETIVO 2 ��� Estudiar el efecto de los tranquilizantes en la calidad tecnol��gica y sensorial de la carne (pH, capacidad de retenci��n de agua, color, textura, olor sexual, ���). Para ello se planteaban dos experimentos, el primero utilizando animales extremos, libres del gen, NN, y Hal +, nn, y el segundo con animales libres, NN, y portadores, Nn.

Meat quality of ten cattle breeds of the Southwest of Europe

A sample of about 70 young bulls of each of ten beef cattle breeds reared in their typical production systems has been characterised with respect to meat quality traits. Breeds included were Asturiana de los Valles, Asturiana de la Monta��a, Avile��a-Negra Ib��rica, Bruna dels Pirineus, Morucha, Pirenaica and Retinta from Spain, and Aubrac, Gasconne and Salers from France. As was previously showed regarding carcass traits, there exist large differences both between and within breed ��� systems. In general, rustic breeds tended to present darker and redder meats with higher haematin contents, whereas less precocious and more specialised breeds showed brighter meats with bigger water losses. Protein content was similar, whereas intramuscular fat presented the larger variations both between and within breeds. ICDH content was higher in the more rustic breeds, showing the predominantly oxidative character of their fibres. Texture measurements showed in general large within breed-system variations, the differences between breeds being less evident. Within breed-system, daily gain weight was positively associated with brighter and tender meats. In the range studied, increasing slaughter weight within breed did not have influence on meat quality. Conformation was related to lower water holding capacity and less dry matter and intramuscular fat, as well as to a lower haematin content giving brighter meats. The increase in fatness scores was related to an augment of toughness in meat specialised breeds, although in Avile��a-Negra Ib��rica breed fatness carcasses were related to more tender meats. Redness parameter a* was positively related to fatter animals and opposed to conformation, the opposite being true for the L* (lightness) parameter. There was a small trend of fatter carcasses to be related to oxidative fibres, whereas the muscular fibres of the more conformed carcasses were more glycolytic. Texture measurements maximum load, maximum stress and toughness were very closely related. Shear force was opposed to tenderness. Losses at cooking were opposed to juiciness, but only in the Spanish breeds. No consistent trends regarding relationships between carcass characteristics and tenderness could be observed. Overall acceptability was primarily related with tenderness and flavour, and later on juiciness.