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Alfonso Ruiz, Leopoldo

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https://academica-e.unavarra.es/handle/2454/48493

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Alfonso Ruiz

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Leopoldo

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Agronomía, Biotecnología y Alimentación

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IS-FOOD. Research Institute on Innovation & Sustainable Development in Food Chain

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0000-0002-5662-9997

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1974

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2005 - 20085
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Now showing 1 - 5 of 5
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    PublicationOpen Access
    Análisis de la relación entre el espesor de la grasa dorsal y el tamaño de los adipocitos en cerdas reproductoras
    (Asociación Interprofesional para el Desarrollo Agrario, 2007) Mendizábal Aizpuru, José Antonio; Abadía Durán, Silvia; Abaurrea Aramburu, Eneko; Alfonso Ruiz, Leopoldo; Producción Agraria; Nekazaritza Ekoizpena
    La correcta gestión de las reservas grasas durante el ciclo productivo de las cerdas reproductoras es un factor clave para la obtención de unos buenos resultados productivos. El principal depósito graso en las cerdas lo constituye el tejido graso subcutáneo, por lo que la medición del espesor graso dorsal es un buen indicador del estado de las reservas corporales. Aunque existen diversos puntos para la medición del espesor, se recomienda hacerlo a nivel de la última costilla flotante, punto que se conoce como P2 (Quiniou, 2004). En esta localización se pueden distinguir hasta tres capas distintas de grasa subcutánea (Moody y Zobrisky, 1966). Distintos trabajos han observado un desarrollo diferencial de las tres capas durante el crecimiento de los animales (Alfonso, 2004; Fortin, 1986), así como diferencias en su actividad lipogénica (Cámara et al., 1996). Por tanto, el estudio de las características de cada capa considerada como distinto depósito graso puede ser importante para conocer los mecanismos de acumulación y movilización de las reservas grasas. En este sentido, en el presente trabajo se estudia la relación entre el espesor de la grasa y el tamaño de los adipocitos de cada una de las capas descritas en la grasa subcutánea dorsal.
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    PublicationOpen Access
    Comparative description of growth, fat deposition, carcass and meat quality characteristics of Basque and Large White pigs
    (EDP Sciences, 2005) Alfonso Ruiz, Leopoldo; Mourot, Jacques; Insausti Barrenetxea, Kizkitza; Mendizábal Aizpuru, José Antonio; Arana Navarro, Ana; Producción Agraria; Nekazaritza Ekoizpena; Gobierno de Navarra / Nafarroako Gobernua
    Characteristics of growth, fat deposition, carcass and meat quality of pigs from the Basque Black Pied breed were described and compared with those of Large White pigs. Four pens, two per breed, of eleven pigs born during the same two week period, were simultaneously fattened and slaughtered, under the same conditions. The experiment was carried out over a fixed duration (124 days) and slaughter was carried out at a fixed average age (202 days). Basque pigs showed lower growth and feed efficiency and higher backfat depth (2.6 vs. 1.7 cm, P < 0.001) than Large White pigs. The difference was especially noticeable in the middle subcutaneous fat layer (0.5 cm, P < 0.001). The meat of Basque pigs was darker, redder, more marbled, and with higher pH values than in Large White pigs. Differences in fatty acid composition were observed between breeds but they were not statistically significant (P > 0.05) because of high variability observed between animals. The Basque breed exhibited an early and higher adipose development and a higher activity of enzymes responsible for lipid synthesis than the Large White. The diameter of intramuscular adipose cells was larger in Basque (40.2 vs. 33.0 μm, P < 0.001) than in Large White pigs. The results show the particular characteristics of the Basque breed as compared to pig lines highly selected for lean growth efficiency.
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    PublicationOpen Access
    The effects of selective breeding against scrapie susceptibility on the genetic variability of the latxa black-faced sheep breed
    (EDP Sciences, 2006) Alfonso Ruiz, Leopoldo; Parada Rey, Analia; Legarra, Andrés; Ugarte, Eva; Arana Navarro, Ana; Producción Agraria; Nekazaritza Ekoizpena
    Breeding sheep populations for scrapie resistance could result in a loss of genetic variability. In this study, the effect on genetic variability of selection for increasing the ARR allele frequency was estimated in the Latxa breed. Two sources of information were used, pedigree and genetic polymorphisms (fifteen microsatellites). The results based on the genealogical information were conditioned by a low pedigree completeness level that revealed the interest of also using the information provided by the molecular markers. The overall results suggest that no great negative effect on genetic variability can be expected in the short time in the population analysed by selection of only ARR/ARR males. The estimated average relationship of ARR/ARR males with reproductive females was similar to that of all available males whatever its genotype: 0.010 vs. 0.012 for a genealogical relationship and 0.257 vs. 0.296 for molecular coancestry, respectively. However, selection of only ARR/ARR males implied important losses in founder animals (87 percent) and low frequency alleles (30 percent) in the ram population. The evaluation of mild selection strategies against scrapie susceptibility based on the use of some ARR heterozygous males was difficult because the genetic relationships estimated among animals differed when pedigree or molecular information was used, and the use of more molecular markers should be evaluated.
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    PublicationOpen Access
    Quality characteristics of Huacaya alpaca fibre produced in the Peruvian Andean Plateau region of Huancavelica
    (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), 2008) Montes Andueza, María; Quicaño, I.; Quispe, R.; Quispe Peña, Edgar; Alfonso Ruiz, Leopoldo; Producción Agraria; Nekazaritza Ekoizpena
    Se describe la calidad de la fibra de alpacas Huacaya producida en la región de Huancavelica (Perú), utilizando una muestra de 203 alpacas pertenecientes a ocho comunidades de alpaqueros ubicadas entre 4.100 y 4.750 m de altitud. El diámetro medio de la fibra, 22,7 μm (SE 0,2), fue inferior a los valores referidos para la raza Huacaya en otras zonas, variando con el sexo, la edad y la comunidad de origen (P < 0,01). Los machos mostraron tener una fibra más fina que las hembras, en contraste con los resultados de otros estudios, aunque puede deberse a que proceden de rebaños seleccionados de Puno y Cusco. No se detectó relación lineal entre el diámetro de la fibra y la longitud de mecha. Antes de iniciar un futuro programa de mejora de la producción de fibra en esa región, se deberían realizar más estudios para conocer mejor los caracteres de producción de fibra y cuantificar su importancia económica. Aunque puede parecer difícil realizar este tipo de investigaciones en la zona alto andina peruana, se vio que es posible si alpaqueros y promotores de desarrollo participan activamente en ellas.
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    PublicationOpen Access
    Use of meta-analysis to combine candidate gene association studies: application to study the relationship between the ESR PvuII polymorphism and sow litter size
    (EDP Sciences, 2005) Alfonso Ruiz, Leopoldo; Producción Agraria; Nekazaritza Ekoizpena
    This article investigates the application of meta-analysis on livestock candidate gene effects. The PvuII polymorphism of the ESR gene is used as an example. The association among ESR PvuII alleles with the number of piglets born alive and total born in the first (NBA1, TNB1) and later parities (NBA, TNB) is reviewed by conducting a meta-analysis of 15 published studies including 9329 sows. Under a fixed effects model, litter size values were significantly lower in the "AA" genotype groups when compared with "AB" and "BB" homozygotes. Under the random effects model, the results were similar although differences between "AA" and "AB" genotype groups were not clearly significant for NBA and TNB. Nevertheless, the most noticeable results was the high and significant heterogeneity estimated among studies. This heterogeneity could be assigned to error sampling, genotype by environment interaction, linkage or epistasis, as referred to in the literature, but also to the hypothesis of population admixture/stratification. It is concluded that meta-analysis can be considered as a helpful analytical tool to synthesise and discuss livestock candidate gene effects. The main difficulty found was the insufficient information on the standard errors of the estimated genotype effects in several publications. Consequently, the convenience of publishing the standard errors or the concrete P-values instead of the test significance level should be recommended to guarantee the quality of candidate gene effect meta-analyses.