Meta-analysis of effects of dietary vitamin E and post slaughter storage conditions on changes of redness (a*) of pork

Abstract. A meta-analysis was carried out to quantify the effects of dietary vitamin E and storage conditions on colour changes of pork from M. longissimus dorsi. After standardisation procedures, redness of pork (CIE colour specification a*), one of the most important objective colour attributes, was used as an indicator for colour changes in this analysis. The analysis was based on results from five experiments, which met selection criteria. Analysis of changes of other objective colour attributes, lightness (L*) and yellowness (b*) was not possible due to lack of published data. The statistical analysis (using mixed models) found significant effects of tissue α-tocopherol concentration in M. longissimus dorsi, simplified supplemented vitamin E levels as well as storage time and storage light on redness of pork and its changes over time. The relationship between redness and α-tocopherol concentration was found to be linear, and between redness and storage time was non-linear (third degree polynomial) in one model. This model suggested that an increase of 1 μg of α-tocopherol in the muscle led to an expected increase a* value of 0.11. Another model identified significant interactions about 0.28 between α-tocopherol concentration and storage time in late storage periods. A third model found a significant difference of −0.48 between predicted a* values at lower (≤50 IU/kg feed) and higher supplemented vitamin E levels (≥100 IU/kg feed). The models predicted an initial increase for 3 days, a stable period for 5 days and then a decrease for a* values over storage time. The a* values were significantly lower by about 1.4 when samples were exposed to light in the models, the effect of light found to be constant over time. Further studies, carried out with standardized methods, are needed to increase the predictive power of the derived models and to validate the models for other muscles. </jats:p

New investigations around CYP11A1 and its possible involvement in an androstenone QTL characterised in Large White pigs

<p>Abstract</p> <p>Background</p> <p>Previously, in boars with extreme androstenone levels, differential expression of the <it>CYP11A1 </it>gene in the testes has been characterised. <it>CYP11A1 </it>is located in a region where a QTL influencing boar fat androstenone levels has been detected in a Large White pig population. Clarifying the role of CYP11A1 in boar taint is important because it catalyses the initial step of androstenone synthesis and also of steroid synthesis.</p> <p>Results</p> <p>A genome-wide association study located <it>CYP11A1 </it>at approximately 1300 kb upstream from SNP H3GA0021967, defining the centre of the region containing the QTL for androstenone variation. In this study, we partially sequenced the <it>CYP11A1 </it>gene and identified several new single nucleotide polymorphisms (SNP) within it. Characterisation of one animal, heterozygous for <it>CYP11A1 </it>testicular expression but homozygous for a haplotype of a large region containing <it>CYP11A1</it>, revealed that variation of <it>CYP11A1 </it>expression is probably regulated by a mutation located downstream from the SNP H3GA0021967. We analysed <it>CYP11A1 </it>expression in LW families according to haplotypes of the QTL region's centre. Effects of haplotypes on <it>CYP11A1 </it>expression and on androstenone accumulation were not concordant.</p> <p>Conclusion</p> <p>This study shows that testicular expression of <it>CYP11A1 </it>is not solely responsible for the QTL influencing boar fat androstenone levels. As a conclusion, we propose to refute the hypothesis that a single mutation located near the centre of the QTL region could control androstenone accumulation in fat by regulating the <it>CYP11A1 </it>expression.</p

Maternal and paternal genomes differentially affect myofibre characteristics and muscle weights of bovine fetuses at midgestation

Postnatal myofibre characteristics and muscle mass are largely determined during fetal development and may be significantly affected by epigenetic parent-of-origin effects. However, data on such effects in prenatal muscle development that could help understand unexplained variation in postnatal muscle traits are lacking. In a bovine model we studied effects of distinct maternal and paternal genomes, fetal sex, and non-genetic maternal effects on fetal myofibre characteristics and muscle mass. Data from 73 fetuses (Day153, 54% term) of four genetic groups with purebred and reciprocal cross Angus and Brahman genetics were analyzed using general linear models. Parental genomes explained the greatest proportion of variation in myofibre size of Musculus semitendinosus (80–96%) and in absolute and relative weights of M. supraspinatus, M. longissimus dorsi, M. quadriceps femoris and M. semimembranosus (82–89% and 56–93%, respectively). Paternal genome in interaction with maternal genome (P<0.05) explained most genetic variation in cross sectional area (CSA) of fast myotubes (68%), while maternal genome alone explained most genetic variation in CSA of fast myofibres (93%, P<0.01). Furthermore, maternal genome independently (M. semimembranosus, 88%, P<0.0001) or in combination (M. supraspinatus, 82%; M. longissimus dorsi, 93%; M. quadriceps femoris, 86%) with nested maternal weight effect (5–6%, P<0.05), was the predominant source of variation for absolute muscle weights. Effects of paternal genome on muscle mass decreased from thoracic to pelvic limb and accounted for all (M. supraspinatus, 97%, P<0.0001) or most (M. longissimus dorsi, 69%, P<0.0001; M. quadriceps femoris, 54%, P<0.001) genetic variation in relative weights. An interaction between maternal and paternal genomes (P<0.01) and effects of maternal weight (P<0.05) on expression of H19, a master regulator of an imprinted gene network, and negative correlations between H19 expression and fetal muscle mass (P<0.001), suggested imprinted genes and miRNA interference as mechanisms for differential effects of maternal and paternal genomes on fetal muscle.Ruidong Xiang, Mani Ghanipoor-Samami, William H. Johns, Tanja Eindorf, David L. Rutley, Zbigniew A. Kruk, Carolyn J. Fitzsimmons, Dana A. Thomsen, Claire T. Roberts, Brian M. Burns, Gail I. Anderson, Paul L. Greenwood, Stefan Hiendlede

Intelligence et médication (vues à travers les résultats de jeunes épileptiques aux échelles de Wechsler)

Larzul B., Kerfriden P., Guillou J., Defer M., Goapper A. Intelligence et médication (vues à travers les résultats de jeunes épileptiques aux échelles de Wechsler). In: Bulletin de psychologie, tome 20 n°257, 1967. pp. 874-879

Sélection pour abaisser le potentiel glycolytique du muscle chez le porc Large White. III. Réponses corrélatives pour la vitesse de croissance, la composition corporelle et les caractères de reproduction

Une expérience de sélection comportant une lignée sélectionnée (S) et une lignée témoin (C) et visant à abaisser le potentiel glycolytique du muscle a été conduite pendant six générations chez des porcs de race pure Large White français présumée indemne des allèles Haln et RN-. L?une et l?autre lignée comprenait six à huit pères et environ 40 mères par génération. Chaque mère produisait deux portées, et le renouvellement se faisait parmi les verrats et truies issus des 1ères portées. Le critère de sélection dans la lignée S était le potentiel glycolytique in vivo (IVGP) du muscle longissimus, mesuré sur un échantillon prélevé par biopsie à un poids vif voisin de 75 kg. Les réponses corrélatives à la sélection pour un faible IVGP ainsi que les héritabilités et les corrélations génétiques avec le IVGP ont été estimées pour le gain moyen quotidien (6761 descendants des 1ères et 2èmes portées), l?épaisseur de lard dorsal mesurée aux ultrasons (3 078 verrats et truies des lr es portées), les caractères de composition de la carcassse (1 185 mâles et femelles des 2èmes portées), l?âge du 1er oestrus (1 084 femelles) et la taille et le poids de la portée à la naissance, à 21 j et au sevrage (917 portées). Les estimées des héritabilités de ces caractères ont été du même ordre de grandeur que les valeurs usuelles de la littérature. Les estimées des corrélations génétiques avec IVGP ont été de 0,15 ± 0,07 pour le gain moyen quotidien, de -0,32 ± 0,06 pour l?épaisseur de lard dorsal mesurée aux ultrasons, -0,20 ± 0,10 pour l?épaisseur de lard dorsal mesurée sur la carcasse, -0,24 ± 0,09 pour le poids de la bardière, 0,18 ± 0,09 pour la teneur en tissu maigre de la carcasse et 0,49 ± 0,15 pour la surface de noix de côtelette.En accord avec les corrélations génétiques concernant les caractères de composition de la carcasse, la plus forte réponse corrélative à la sélection pour un faible IVGP a été une diminution du rapport muscle/gras de la carcasse dans la lignée S par rapport à la lignée témoin. Les tendances génétiques par génération se sont élevées respectivement à -0,13, 0,12 et 0,16 unité d?écart-type phénotypique pour le pourcentage de muscle, l?épaisseur de lard dorsal et le poids de la bardière. Une corrélation génétique négative (-0,29 ± 0,11) a été trouvée entre l?âge au le 1er oestrus et IVGP, mais il n?y a eu aucune indication d?association génétique significative avec IVGP ou de réponses corrélatives à la sélection notables dans la lignée S en ce qui concerne les caractères de taille et de poids de la portée

Bone allografts and supercritical processing: effects on osteointegration and viral safety

4th International Symposium on Supercritical Fluids (ISSF 97), SENDAI, JAPAN, MAY 11-14, 1997International audienceA new bone tissue process using supercritical carbon dioxide extraction was evaluated for viral inactivation and the allografts produced by this process were tested in an in vivo implantation experiment. Four viruses, human immunodeficiency virus type I (HIV-1), Sindbis virus, Polio Sabin type I virus and Pseudorabies virus (PRV) were assayed. Four processing stages, supercritical CO,, hydrogen peroxide, sodium hydroxide and ethanol treatments were also tested. The efficiency of the process was assessed in terms of reduction factors which are the log,, of the ratio of the virus load before and after the stage to be evaluated. The cumulated reduction factors were the following: > 18.2 for Sindbis virus, > 24.4 for Poliovirus, > 17.6 for PRV and > 14.2 for HIV-1. Such allografts processed in this way were implanted into sheep leading to a much faster osseointegration in comparison with non-treated allografts. The combination of better graft incorporation and viral safety suggest that this process could become a new way for processing bank bones, alternatively or additionally, to the procedures presently used