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Nouzilly, France

Collewet G.,IRSTEA | Collewet G.,European University of Brittany | Bugeon J.,French National Institute for Agricultural Research | Idier J.,French National Center for Scientific Research | And 6 more authors.
Food Chemistry | Year: 2013

The potentiality of MRI to quantify fat content in flesh and subcutaneous fat in fish cutlets was investigated. Low measurement time was aimed at in a view to handling large number of samples needed in selective breeding programs for example. Results on fresh and frozen-thawed cutlets were compared to assess this way of conservation. As MRI generates unwanted spatial variations of the signal, a correction method was developed enabling the measurement on several cutlets simultaneously in less than 3 min per sample. For subcutaneous fat, the results were compared with vision measurements. High correlations between both techniques were found (R2 = 0.77 and 0.87 for the ventral and dorsal part). Fat in flesh was validated vs NMR measurements. No statistical difference was found between fresh and frozen-thawed cutlets. RMSE was respectively 0.8% and 0.89%. These results confirmed the potentiality of MRI for fat measurement in fish particularly for a large number of samples. © 2012 Elsevier Ltd. All rights reserved.

Chapuis H.,SYSAAF | Pincent C.,Choice Genetics France | Colleau J.J.,French National Institute for Agricultural Research
Journal of Animal Breeding and Genetics | Year: 2016

Summary: Poultry breeding schemes permanently face the need to control the evolution of coancestry and some critical traits, while selecting for a main breeding objective. The main aims of this article are first to present an efficient selection algorithm adapted to this situation and then to measure how the severity of constraints impacted on the degree of loss for the main trait, compared to BLUP selection on the main trait, without any constraint. Broiler dam and sire line schemes were mimicked by simulation over 10 generations and selection was carried out on the main trait under constraints for coancestry and for another trait, antagonistic with the main trait. The selection algorithm was a special simulated annealing (adaptative simulated annealing (ASA)). It was found to be rapid and able to meet constraints very accurately. A constraint on the second trait was found to induce an impact similar to or even greater than the impact of the constraint on coancestry. The family structure of selected poultry populations made it easy to control the evolution of coancestry at a reasonable cost but was not as useful for reducing the cost of controlling evolution of the antagonistic traits. Multiple constraints impacted almost additively on the genetic gain for the main trait. Adding constraints for several traits would therefore be justified in real life breeding schemes, possibly after evaluating their impact through simulated annealing. © 2016 Blackwell Verlag GmbH.

Suquet M.,French Research Institute for Exploitation of the Sea | Labbe C.,French National Institute for Agricultural Research | Puyo S.,SYSAAF | Mingant C.,French Research Institute for Exploitation of the Sea | And 5 more authors.
PLoS ONE | Year: 2014

This study is the first demonstration of successful post-thawing development to reproduction stage of diploid cryopreserved larvae in an aquatic invertebrate. Survival, growth and reproductive performances were studied in juvenile and adult Pacific oysters grown from cryopreserved embryos. Cryopreservation was performed at three early stages: trochophore (13±2 hours post fertilization: hpf), early D-larvae (24±2 hpf) and late D-larvae (43±2 hpf). From the beginning (88 days) at the end of the ongrowing phase (195 days), no mortality was recorded and mean body weights did not differ between the thawed oysters and the control. At the end of the growing-out phase (982 days), survival of the oysters cryopreserved at 13±2 hpf and at 43±2 hpf was significantly higher (P<0.001) than those of the control (non cryopreserved larvae). Only the batches cryopreserved at 24±2 hpf showed lower survival than the control. Reproductive integrity of the mature oysters, formely cryopreserved at 13±2 hpf and 24±2 hpf, was estimated by the sperm movement and the larval development of their offspring in 13 crosses gamete pools (five males and five females in each pool). In all but two crosses out of 13 tested (P<0.001), development rates of the offspring were not significantly different between frozen and unfrozen parents. In all, the growth and reproductive performances of oysters formerly cryopreserved at larval stages are close to those of controls. Furthermore, these performances did not differ between the three initial larval stages of cryopreservation. The utility of larvae cryopreservation is discussed and compared with the cryopreservation of gametes as a technique for selection programs and shellfish cryobanking. © 2014 Suquet et al.

Bugeon J.,Genopole | Lefevre F.,Genopole | Cardinal M.,French Research Institute for Exploitation of the Sea | Uyanik A.,Genopole | And 2 more authors.
Journal of Muscle Foods | Year: 2010

Rainbow trout with different fillet yield [56 and 65% for low (LY) and high yield (HY), respectively] were examined for muscle organization and flesh quality (instrumental and sensorial evaluations). Both groups had similar body weight (3.6 kg in mean), but the HY group had a higher carcass yield (+15%). Higher total muscle area in the HY group (+20%) was associated with a higher number of muscle fibers (+22%). Flesh of the HY group presented a higher area of myosepta (+10%), fat content (+10%) and luminosity (+6%). Raw fillet mechanical resistance was higher for the HY group; an opposite result was obtained for cooked flesh. Sensorial evaluation of cooked flesh revealed no important differences between groups. Smoked fillet from the HY group presented higher area of white stria and lower flesh color intensity. To conclude, higher muscle mass content had no negative consequences on flesh quality in rainbow trout. © 2010, The Author(s). Journal of Muscle Foods © 2010, Wiley Periodicals, Inc.

de Verdal H.,French National Institute for Agricultural Research | Narcy A.,French National Institute for Agricultural Research | Bastianelli D.,CIRAD - Agricultural Research for Development | Chapuis H.,SYSAAF | And 4 more authors.
BMC Genetics | Year: 2011

Background: Feed costs represent about 70% of the costs of raising broilers. The main way to decrease these costs is to improve feed efficiency by modification of diet formulation, but one other possibility would be to use genetic selection. Understanding the genetic architecture of the gastro-intestinal tract (GIT) and the impact of the selection criterion on the GIT would be of particular interest. We therefore studied the genetic parameters of AMEn (Apparent metabolisable energy corrected for zero nitrogen balance), feed efficiency, and GIT traits in chickens.Genetic parameters were estimated for 630 broiler chickens of the eighth generation of a divergent selection experiment on AMEn. Birds were reared until 23 d of age and fed a wheat-based diet. The traits measured were body weight (BW), feed conversion ratio (FCR), AMEn, weights of crop, liver, gizzard and proventriculus, and weight, length and density of the duodenum, jejunum and ileum.Results: The heritability estimates of BW, FCR and AMEn were moderate. The heritability estimates were higher for the GIT characteristics except for the weights of the proventriculus and liver. Gizzard weight was negatively correlated with density (weight to length ratio) of duodenum, jejunum and ileum. Proventriculus and gizzard weights were more strongly correlated with AMEn than with FCR, which was not the case for intestine weight and density.Conclusions: GIT traits were largely dependent on genetics and that selecting on AMEn or FCR would modify them. Phenotypic observations carried out in the divergent lines selected on AMEn were consistent with estimated genetic correlations between AMEn and GIT traits. © 2011 de Verdal et al; licensee BioMed Central Ltd.

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