Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Estimation of crossbreeding parameters between Large White and Meishan porcine breeds. III. Dominance and epistatic components of heterosis on reproductive traits | Genet Sei Evol 1993 25 263-281 Elsevier INRA 263 Original article Estimation of crossbreeding parameters between Large White and Meishan porcine breeds. III. Dominance and epistatic components of heterosis on reproductive traits JP Bidanel INRA Station de Génétique Quantitative et Appliquée Centre de Recherches de Jouy-en-Josas 78352 Jouy-en-Josas Cedex France Received 31 July 1991 accepted 20 January 1993 Summary A crossbreeding experiment using Large White LW and Meishan MS pig strains was conducted. Dominance additive X additive and dominance X dominance epistatic components of direct and maternal heterosis effects were investigated for various litter productivity and sow traits total number born TNB number born alive NBA number weaned NW litter weight at birth LWB and at 21 d LW21 either adjusted or not for litter size sow weight loss SWL sow total SFC and maximum SFCM feed consumption sow feed efficiency - computed as SFC per piglet weaned SFC NW or per unit of litter weight gain SFC LWG - during lactation. Data from 1148 litters farrowed by 250 sows were analysed. Models involving all possible combinations of dominance and epistatic parameters were compared for goodness of fit on the basis of their mean squared error MSE . The model with the lowest MSE was then used to estimate crossbreeding parameters. Models involving dominance effects only for maternal heterosis had the lowest MSE for all litter productivity traits. Dominance also appeared as the main component of direct heterosis effects on litter productivity traits. Favourable dominance and unfavourable epistatic effects contributed to direct heterosis effects for all sow traits except SFCM. Epistatic effects were additive X additive effects for SFC NW and dominance X dominance effects for SWL SFC and SFC LWG. Estimates of direct maternal and grand-maternal breed effects are presented. A possible contribution of cytoplasmic effects to between-breed variation is also hypothesized. pig Chinese breed .
