Relative growth in rabbits: the effects of genetic line, diet and gender

[EN] The relative growth of different parts of the body and tissues was analysed using an allometric model. Animals were crossbred rabbits (males and females) from the mating of commercial lines HYLA-grand parental doe (HY-GPD) female with HYLA Coloured (HY-CO) or Grimaud (GR) males, both selected for the growth rate, or HY-GPD males, selected for weaning weight. They were fed on two different diet, mainly differing in their energy content, and the relative growth of the different parts of their body was assessed. The components with a nearly isometric growth pattern, which grew at the same mean rate as the rest of the body, were skin, chilled carcass and reference carcass; hind legs for retail cuts; and dorsal and carcass length for linear measurements. All allometric coefficients were calculated with respect to the slaughter weight, except percentage of hind leg inter-intramuscular fat (IIMF), which was calculated with respect to the weight of the hind leg. The components that showed early maturing were liver, kidneys, breast and rib viscera for offal and organs; head and breast and ribs for retail cuts; and bone and IIMF percentage of the hind leg. The components with late maturing were forelegs and loin for retail cuts, inguinal, scapular and perirenal fat, meat of the hind leg, and thigh and lumbar circumference length for carcass linear measurements. The GR line showed earlier growth for loin than the maternal HY-GPD line. In addition, the GR and HY-CO lines developed scapular and inguinal fat later than the HY-GPD line. For IIMF percentage, GR presented later growth than HY-CO and HY-GPD. The main effect of the diet was on liver development and on scapular fat: rabbits fed on the high-energy diet showed later liver and scapular fat growth.Martínez-Bas, AM.; Kessler, M.; Armero, E. (2018). Relative growth in rabbits: the effects of genetic line, diet and gender. 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Evaluation of elevated dietary corn fiber from corn germ meal in growing female pigs. J. Anim. Sci., 88: 192-201. https://doi.org/10.2527/jas.2009-1896Whittemore C.T. 1998. The Science and practice of pig production. (2nd ed.) Oxford. Longman Scientific and Technical

Effect of the geographical origin on the presence of skeletal deformities and swimbladder anomaly in a cultured gilthead sea bream (Sparus aurata L) population. Estimation of genetic parameters

The gilthead sea bream (Sparus aurata L.) is one of the most important Sparid farmed in Europe. However, abnormalities such us lordosis, lack of operculum and failure to inflate the swimbladder constitute a major problem for aquaculture industry by decreasing the final value of the fish. The use of stocks from different genetic origin to produce commercial fish usually cause great variability in the global quality of the end product. However, strategies that involve the development of selection schemes in sea bream for these traits of economic interest are scarce. In light of these circumstances, the effect of the geographical origin on the presence of anomalies as a measure of fish quality was analyzed. For this purpose a population of farmed gilthead sea bream obtained from broodstock from three differentiated geographical origin and reared under common conditions was analyzed from X‐ray photograph for the mayor anomalies present in this species. A posteriori reconstruction of pedigree was carried out in order to determine genetic parameters for fish anomalies. An effect of the geographical origin on the presence of skeletal malformation and on the lack of functional swimbladder was found, being lordosis and lack of operculum the most common skeletal deformities. Heritabilities were medium for lack of operculum and lack of functional swimbladder and high for lordosis. A medium genetic correlation and a positive phenotypic correlation were observed between the lack of functional swimbladder and lordosis. All these findings could be relevant for the establishment of successful breeding programs in aquaculture of this species.This study was supported by the PROGENSA® project. Spanish Ministry of Environment, Rural and Marine, JACUMAR

Economic sensitivity analysis on the profitability of production of rabbit meat.

[SPA] En el presente proyecto se planteó buscar alternativas en la comercialización de la carne de conejo que le den valor añadido y/o que le abra la puerta a nuevos mercados y mejore la rentabilidad de las explotaciones ganaderas. Para llevar a cabo el estudio, se seleccionaron 2.294 conejos a las 8 semanas de edad (machos y hembras, uno de cada camada) de tres líneas genéticas (Ebro, Grimaud e Hyla), la mitad de cada una de las líneas se alimentó con un pienso distinto (dieta A y dieta B), hasta que alcanzaron las 16 semanas de edad que finalizó el ensayo. A partir de la doceava semana tanto en machos como en hembras el beneficio deja de ser positivo, ya que los gastos de producción superan al beneficio obtenido por conejo. Por tanto, contrastando con los resultados obtenidos en capítulos anteriores de crecimiento, adoptamos como semana óptima al sacrificio la onceava, como línea genética Ebro y como dieta la más energética (B), tanto machos como hembras. Además este beneficio se complementará con la venta de productos transformados de alto valor añadido para los cuales se aprovecharán grasas intra e intermusculares. [ENG] In this project it was raised look for alternatives in the marketing of rabbit meat that gives added value and / or open the door to new markets and improve the profitability of farms. To perform the study, 2294 rabbits were selected at 8 weeks of age (male and female, one from each litter) three genetic lines (Ebro, Grimaud and Hyla), half of each of the lines fed a feed different (diet and diet B) until they reached 16 weeks old trial ended. From the twelfth week in both males and females benefit ceases to be positive, because production costs outweigh the benefit obtained by rabbit. Therefore, in contrast to the results obtained in earlier chapters of growth, we adopt as optimal slaughter the eleventh, as genetic line Ebro week and as the most energy diet (B), both males and females. Furthermore, this benefit will be supplemented by the sale of processed products with high added value for which intra and inter-fats be exploited.La realización del presente trabajo ha sido posible gracias al apoyo económico del proyecto CDTI (IDI-20120024) “Introducción de nuevos parámetros productivos en explotación cunícola para la obtención de productos de alto valor añadido”. Agradecer también el apoyo técnico de la empresa QUIN s.l. y de mis compañeros del grupo de investigación. Así como a mis directores de tesis

Physiological indicators of stress in gestating sows under different cooling systems

 objetivo deste trabalho foi determinar os marcadores fisiológicos de estresse, a razão entre neutrófilos e linfócitos (N/L) e as concentrações de corticoides em porcas gestantes submetidas a diferentes sistemas de refrigeração. Foram utilizados um sistema de refrigeração com aspersores (SS) e um sistema baseado em painel evaporativo de celulose com ventilador (PS). O SS apresentou maior proporção N/L (1,095) que o PS (0,850). As concentrações de corticoides tiveram alta variabilidade. Os corticoesteroides são indicadores de estresse mais eficientes em curto prazo, enquanto a proporção N/L é um bom indicador de estresse em médio e longo prazo. De acordo com a proporção N/L, as porcas gestantes submetidas ao PS se beneficiaram de maior bem-estar.The objective of this work was to determine physiological stress markers, neutrophil:lymphocyte ratio (N/L) and corticoid concentrations, in gestating sows under different cooling systems. A sprinkling cooling system (SS) and a system based on fan-assisted evaporative cellulose pad (PS) were used. SS showed higher N/L ratio (1.095) than PS (0.850). Corticoid concentrations showed high variability. Corticosteroids are more efficient short-term stress indicators while N/L ratio is a good medium and long-term stress indicator. According to N/L ratio, gestating sows under PS benefit from a higher level of welfare

Composition of fatty acids of the rabbit meat in function of the genetic line and the diet

[SPA] El efecto de dos dietas con diferentes niveles de fibra en la composición del perfil de ácidos grasos de la carne de conejo fue estimado para un total de 150 animales de tres líneas genéticas diferentes (Ebro - EB y Grimaud - GR, seleccionados por velocidad de crecimiento e Hyla - HY seleccionada por aptitud maternal). Los animales fueron alimentados con una dieta control (C) (25% de fibra) y otra más energética (HE) (17% de fibra). Tras el sacrificio a las 8 y a las 12 semanas de edad analizamos el contenido nutricional de la carne de una pata trasera, obteniendo el porcentaje de grasa intramuscular y el perfil de ácidos grasos. Observamos que el contenido de grasa intramuscular desciendió conforme avanza la edad, al igual que el ratio omega 6/omega 3 (P< 0,05). La línea de aptitud maternal (HY) presentaron diferencias significativas respecto a EB y GR en el contenido de PUFA a las 12 semanas, siendo mayor su concentración de estos ácidos grasos. Respecto a las dos dietas, hay diferencias en el ácido palmítico (C16:0) a las 12 semanas teniendo un contenido superior los animales alimentados con la dieta HE (28,97 % ± 0,05) que los alimentados con la dieta C (27,75 % ± 0,05). Así, el contenido en ácidos grasos puede ir influenciado por la edad, por la línea genética, y en menor medida por la dieta. [ENG] The effect of two diets with different fiber levels on the composition of the fat profile of the rabbit meat was estimated for a total of 150 animals from three different genetic lines (Ebro - EB and Grimaud - GR, selected by growth rate and Hyla - HY selected by maternal aptitude). The animals were fed a control diet (C) (25% fiber) and another energy (HE) (17% fiber). After slaughter at 8 and 12 weeks of age, the nutritional content of the meat of a hind leg, was analyzed obtaining the percentage of intramuscular fat and the profile of fatty acids. We observed that the intramuscular fat content decreased according to age, as did the omega 6 / omega 3 ratio (P <0.05). The maternal aptitude line (HY) presented significant differences respect to EB and GR in the PUFA content at 12 weeks, with a higher concentration of these fatty acids. With respect to both diets, there is differences in palmitic acid (C16: 0) at 12 weeks with a higher content of animals fed with the HE diet (28.97% ± 0.05) than foods with C diet (27.75% ± 0.05). Thus, the fat content can be influenced by the age, by the genetic line, and to a lesser extent by the diet.La realización del presente trabajo ha sido posible gracias al apoyo económico del proyecto CDTI (IDI-20120024) y al apoyo técnico de la empresa QUIN s.l

Composition of fatty acids of the rabbit meat in function of the genetic line and the diet

[SPA] El efecto de dos dietas con diferentes niveles de fibra en la composición del perfil de ácidos grasos de la carne de conejo fue estimado para un total de 150 animales de tres líneas genéticas diferentes (Ebro - EB y Grimaud - GR, seleccionados por velocidad de crecimiento e Hyla - HY seleccionada por aptitud maternal) alimentados con una dieta control (C) (25% de fibra) y otra más energética (HE) (17% de fibra). A las 8 y a las 12 semanas de edad analizamos el porcentaje de grasa intramuscular y el perfil de ácidos grasos. El contenido de grasa intramuscular desciende conforme avanza la edad, al igual que desciende el ratio omega 6/omega 3 (P< 0,05). HY presenta diferencias significativas respecto a EB y GR en el contenido de ácidos grasos poliinsaturados a las 12 semanas, siendo mayor su concentración de estos ácidos grasos. El ácido palmítico (C16:0) a las 12 semanas teniendo un contenido superior los animales alimentados con la dieta HE (28,97 % ± 0,05) que los alimentados con la dieta C (27,75 % ± 0,05). Así el contenido en ácidos grasos puede ir influenciado por la edad, por la línea genética, y en menor medida por la dieta. [ENG] The effect of two diets with different fiber levels on the composition of the fat profile of the rabbit meat was estimated for a total of 150 animals from three different genetic lines (Ebro - EB and Grimaud - GR, selection by growth rate and Hyla - HY selected by maternal aptitude). The animals were fed a control diet (C) (25% fiber) and another energy (HE) (17% fiber). After slaughter at 8 and 12 weeks of age, we obtained the percentage of intramuscular fat and the profile of fatty acids. We observed that the intramuscular fat content decreased according to age, as did the omega 6/omega 3 ratio (P <0.05). The maternal aptitude line (HY) presents significant differences respect to EB and GR in the PUFA content at 12 weeks, with a higher concentration of these fatty acids. With respect to both diets, there is differences in palmitic acid (C16: 0) at 12 weeks with a higher content of animals fed with the HE diet (28.97% ± 0.05) than foods with C diet (27.75% ± 0.05). Thus, the fat content can be influenced by the age, by the genetic line, and to a lesser extent by the diet.La realización del presente trabajo ha sido posible gracias al apoyo económico del proyecto CDTI (IDI-20120024) y al apoyo técnico de la empresa QUIN S.L

Establishment of a sea bream (Sparus aurata) breeding program in the Region of Murcia

[SPA] La dorada es una especie que ocupa un papel importante dentro de la acuicultura española y cuya crianza se ha consolidado dentro del contexto europeo. A pesar de ello, su producción industrial presenta aun importantes inconvenientes como son la presencia de anomalías morfológicas desde edades muy tempranas o crecimientos no maximizados, entre otros. Para sobrellevar dichos inconvenientes las empresas llevan a cabo distintas actuaciones relacionadas con la alimentación, manejo de sus lotes, prevención de enfermedades e incluso la ubicación de sus instalaciones. Sin embargo, han sido muy escasas las estrategias que han implicado intervención genética sobre los núcleos de reproductores y por tanto, del estrato productivo, a través del desarrollo de programas de selección para caracteres de interés económicos para los piscicultores. Con este fin, el objetivo de la presente tesis es obtener alevines de dorada a partir de un lote de reproductores que se encuentran en el Instituto Español de Oceanografía, planta de Cultivos Marinos en la Azohía (Murcia), identificarlos individualmente con Passive Integrated Transponder, y criarlos bajo las mismas condiciones industriales de una empresa representativa de la Región (Servicios Atuneros del Mediterráneo). Esta población será analizada para caracteres de crecimiento y para otros caracteres escasamente tratados o desconocidos en dorada, como los de calidad de canal y de carne. [ENG] To overcome these drawbacks, companies carry out various actions related to food, handling their lots, preventing diseases and even the location of their facilities. However, the strategies that have involved genetic intervention on the breeding nuclei and, therefore, the productive stratum, have been very scarce and simple, through the development of selection programs for characters of economic interest for fish farmers.To this end, the objective of this thesis is to obtain seabream fingerlings from a batch of broodstock that are in the Spanish Institute of Oceanography, Marine Crops plant in the Azohía (Murcia), identify them individually with Passive Integrated Transponder, and raise them under the same industrial conditions of a company representative of the Region (Mediterranean Tuna Services). This population will be analyzed for growth characters and for other scarcely treated or unknown characters in gilthead bream, such as those of carcass and meat quality.A la Consejería de Agricultura, Agua y Medio Ambiente de la Región de Murcia (BORM 234, 7 octubre 2016) por su soporte económico. La realización de la presente tesis doctoral es continuación del proyecto “Desarrollo de un Programa Piloto de Mejora Genética en Dorada (Sparus aurata L.)” [9] http://www.progensa.eu, financiado por la Secretaria de la Junta Nacional Asesora de Cultivos Marinos (JACUMAR)

Development of the first microsatellite multiplex PCR panel for meagre (Argyrosomus regius), a commercial aquaculture species

In this study, a microsatellite-based multiplex PCR panel for meagre (Argyrosomus regius) was developed as a useful and single tool in parental assignment and population studies. Twenty-one specific and interspecific microsatellites from different aquaculture species of meagre (Argyrosomus regius), Japanese meagre (A. japonicus), red drum (Sciaenops ocellatus) and yellow meagre (Acoupa weakfish) were assessed for genetic variability, allelic range and genotype reliability. Finally, a SuperMultiplex for Argyrosomus regius (SMAr) was designed with only the best eight microsatellite markers. The panel assessment was performed using a batch of brood stock from one company and a sample of 616 offspring. It was possible to assign 95% of the offspring to a single pair of parents using the exclusion method. It is therefore considered an easy procedure, and a powerful and low-cost tool for parental assignment to support companies’ breeding programs and to exchange information between research groups.This research was funded by Fundación Séneca-Agencia de Ciencia y Tecnología de la Región de Murcia through the project “Mejora de la competitividad del sector de la corvina a través de la selección genética (GENECOR, 21002/PI/18)” in the call for grants for projects for the development of scientific and technical research by competitive groups, included in the Regional Program for the Promotion of Scientific and Technical Research (Action Plan 2018). A.V. was funded by a pre-doctora research fellowship (20716/FPI/18. Fundación Séneca. Cofinanciado por grupo Avramar S.L. Región de Murcia (Spain)). The Avramar S.L. group provided financial support and the use of its facilities for this study

Genetic Analysis of the Fatty Acid Profile in Gilthead Seabream (Sparus aurata L.).

The gilthead seabream is one of the most valuable species in the Mediterranean basin both for fisheries and aquaculture. Marine fish, such as gilthead seabream, are a source of n3 polyunsaturated fatty acids, highly appreciated for human food owing to their benefits on the cardiovascular and immune systems. The aim of the present study was to estimate heritability for fatty acid (FA) profile in fillet gilthead seabream to be considered as a strategy of a selective breeding program. Total of 399 fish, from a broodstock Mediterranean Sea, were analysed for growth, flesh composition and FA profile. Heritabilities for growth traits, and flesh composition (fat, protein, and moisture content) were medium. Heritability was moderate for 14:0, 16:0 and 18:1n9 and for sum of monounsaturated FA and n6/n3 ratio, and it was low for 20:1n11 and 22:6n3 and the ratio unsaturated/saturated FA. Breeding programs in gilthead seabream usually include growth as the first criterion in the selection process of the fish. However, other quality traits, such as fillet fat content and its fatty acids profile should be considered, since they are very important traits for the consumer, from a nutritional point of view and the benefits for the health.Versión del edito