Muscle Hypertrophy of Genetic Origin and its use to Improve Beef Production

This publication contains the proceedings of a seminar held in Toulouse, France, on 10th, 11th and 12th June 1980, under the auspices of the Commission of the European Communities, Directorate General for Agriculture, Division for the Coordination of Agricultural Research, as part of a programme of research on beef production. The seminar was intended to bring together available experience on the utilisation of hereditary muscular hypertrophy for meat production in the member states of the European Communities. Although the phenomenon of double muscling has been exploited in various countries, particularly France, Italy and Belgium, different breeds are used and different methods of exploitation employed. An attempt was therefore made to bring together the collective experience of participants. Contributions ranged from those on the inheritance of muscular hypertrophy to alternative production systems and from fundamental studies of muscle growth to practical ways of selling the additional musrile found in animals with muscular hypertrophy. The collection of assembled papers and discussions thus represents one of the most extensive reviews of the subject that has been attempted.

Contenu
Session I: Opening of the Seminar.- Research Activities on Hereditary Muscular Hypertrophy.- Session II: Effect of Muscle Hypertrophy on Performance.- General Survey of the Effect of Double Muscling on Cattle Performance.- A Comparison of Normal and Heterozygous Animals for Double Muscling in British Breeds of Cattle.- Discussion.- Muscular Development and Energy Utilisation in Cattle: The Double Muscled as an Extreme or a Deviant Animal.- Some Nutritional Particularities of Pig Breeds with High Muscle Development (Pietrain, Belgian Landrace).- Discussion.- Session III: Nature and Origin of Muscle Hypertrophy: Biological Determination.- Carcase Composition and Muscle Structure in Hypertrophied Animals.- Discussion.- Beef Carcase Conformation and Some Biological Implications.- Discussion.- Relationship Between Muscle Hypertrophy and the Composition of Skeletal Muscles.- Discussion.- The Effect of the Hypertrophied Type on Carcase Composition and Muscle Distribution in the Maine Anjou Breed.- Discussion.- Muscle and Adipose Tissue from Normal and Double Muscled Cattle: Collagen Types, Muscle Fibre Diameter, Fat Cell Size and Fatty Acid Composition and Organoleptic Properties.- Discussion.- The Effect of the Hypertrophied type on Morpho-Anatomical Characteristics of the Perimysium in the Maine-Anjou Breed.- Creatinine Variation in Transmission of Muscle Hypertrophy in Piemontese Cattle.- Discussion.- Creatine and Creatinine Levels in Plasma, Red Cells and Muscles as Characteristics of Double-Muscled Cattle.- Discussion.- Stereological Analyses of Hypertrophic Muscle Fibres.- Discussion.- Quantitative Histochemistry of Muscle Enlargement and Post Mortem Metabolism.- Discussion.- Comparative Study of Muscular Tissue of Normal and Double Muscled Maine-Anjou Bull Calves: DNA and Metabolism.- Discussion.- Biochemical and Histochemical Study of Skeletal Muscles in Four Breeds of Rabbit.- Studies on the 7th Rib Cut in Double Muscled and Conventional Cattle. Anatomical, Histological and Biochemical Aspects..- Endocrinological Studies On Double Muscled Cattle; LH, GH, Testosterone and Insulin Plasma Levels During the First Year of Life.- Discussion.- General Discussion.- Session IV. Genetic Determination and Selection on Muscle Hypertrophy.- Present State of Knowledge about the Genetic Determination of Muscular Hypertrophy or the Double Muscled Trait in Cattle.- Genetic Determination of Muscular Hypertrophy in the Pig.- A Simulation Study of the Population Dynamics of the Double Muscled Gene with Selection for Heterozygote Advantage.- Muscular Hypertrophy as a Racial Characteristic: The Case of the Belgian Blue Breed.- A Note on the Recent History of Piemontese Cattle Surveying the Genetic Determination of Muscle Hypertrophy.- Herd Structure of Pedigree Piedmont Cattle.- Double Muscled Character in Spanish Breeds of Cattle.- Advantages of Using Double Muscled Sires in Crossbreeding and the Selection of a Specialised Double Muscled Sire Line in France.- Preliminary Results of A Selection Experiment for Muscle Hypertrophy in the Pietrain Breed.- General Discussion.- Session V: Use of Double Muscled Cattle and Related Problems.- Analytical Study on Retail Cuts from the Double Muscled Animal.- Analysis of Reproduction Problems in Double Muscled Females.- Discussion.- Production Systems with Double Muscled Belgian Blue Cattle.- Characteristics of the Meat Production from Belgian White Blue Cattle.- Discussion.- Muscular Hypertrophy and its Significance for Beef Production in the Netherlands.- Discussion.- The Possibilities of Exploiting DoubleMuscling of Cattle in UK Beef Production.- Comparison of Sire Breeds Represented by Double Muscled and Normal Sires.- Discussion.- Session VI: Final Conclusions and Perspectives.- Final Conclusions and Perspectives.- List of Participants.