tailieunhanh - Báo cáo sinh học: "Genetic analyses of Bantam and selected low-weight White Plymouth Rock chickens and their crosses. I. Growth, immunoresponsiveness and carcass "

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Genetic analyses of Bantam and selected low-weight White Plymouth Rock chickens and their crosses. I. Growth, immunoresponsiveness and carcass | Genet Sei Evol 1991 23 141-148 Elsevier INRA 141 Original article Genetic analyses of Bantam and selected low-weight White Plymouth Rock chickens and their crosses. I. Growth immunoresponsiveness and carcass characteristics EA Dunnington PB Siegel Virginia Polytechnic Institute and State University _ Poultry Science Department Blacksburg VA 24061-0332 USA Received 30 April 1990 accepted 18 January 1991 Summary - Two populations of small White Plymouth Rock chickens one selected for low 8-wk body weight and the other a line of Bantam were crossed to produce reciprocal Fl s. In the next generation individuals of the parental and reciprocal Ẹ1 populations were mated to produce all 16 possible populations including parentals Fl s F2 s and backcrosses. Because the Bantam had been developed to reach a small mature size and the line of low-weight selected chickens had been selected for low juvenile body weight differences in growth patterns and carcass composition were apparent. Bantams weighed less at hatch and at maturity but were heavier from 2-12 wk of age. Bantams also had proportionately more breast muscle and total body lipid than low-weight line pullets. Highly significant differences due to parental effects heterosis and recombination loss occurred for body weights. Skeletal growth paralleled that of body weights Immunoresponsiveness was not different in the 2 parental populations and was not subject to heterosis or recombination loss. selection Bantam chickens growth carcass Resume - Analyses génétiques de deux lignées de poules Plymouth Rock Blanche 1 une Bantam et 1 autre sélectionnée pour un faible poids et de leurs croisements. I. Croissance aptitude à la réponse immunitaire et caractères de carcasse. Deux populations de petites poules de race Plymouth Rock Blanche I une sélectionnée pour un foible poids à 8 semaines I autre une lignée de Bantam ont été croisées pour produire des Ft rệcịproques. A la generation suivante les individus des populations .