Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Genetic variability of muscle biological characteristics of young Limousin bulls | 287 Genet Sei Evol 1995 27 287-298 Elsevier INRA Original article Genetic variability of muscle biological characteristics of young Limousin bulls G Renand1 c Jurie2 J Robelin2 B Picard2 Y Geay2 F Ménissier1 1 Institut national de la recherche agronomique station de génétique quantitative et appliquée 78352 Jouy-en-Josas cedex France 2 Institut national de la recherche agronomique laboratoire croissance et métabolisme des herbivores UR croissance musculaire 63122 Saint-Genès-Champanelle France Received 6 May 1994 accepted 13 January 1995 Summary - Genetic parameters of 4 muscle biological characteristics protein to DNA ratio Pro DNA lactate dehydrogenase LDH activity isocitrate dehydrogenase ICDH activity and the proportion of type I myosin heavy chains MHC I in the Semitendi-nosus and the Longissimus thoracis were estimated simultaneously with average daily gain ADG 480-d final weight FW carcass lean and fat contents CL and CF respectively in a sample of young Limousin bulls tested in station. The data came from 144 animals the progeny of 15 sires. Sire and residual variances and covariances were estimated using an expectation maximization restricted maximum likelihood EM-REML procedure applied to a multitrait mixed model. Heritability coefficients of production traits ADG FW CL and CF were and respectively while heritability coefficients of muscle characteristics Pro DNA LDH ICDH and MHC I were and respectively in the Semitendinosus muscle and and respectively in the Longissimus thoracis muscle. In both muscles the oxidative activity of the ICDH appeared to be genetically associated with the proportion of type I myosin heavy chains and opposed to the glycolytic activity of the LDH. The LDH activity was clearly associated with higher muscle-to-fat ratio while the opposite relationship was observed between that ratio and the ICDH activity or the MHC I proportion. beef cattle genetic parameter growth .
