Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: A comparison of genetic data from New Zealand and France on twin calving in cattle | 345 Genet Sei Evol 1991 23 345-350 Elsevier INRA Note A comparison of genetic data from New Zealand and France on twin calving in cattle CA Morris1 JL Foulley2 1 Ministry of Agriculture and Fisheries Ruakura Agricultural Centre PB Hamilton New Zealand 2 Institut National de la Recherche Agronomique Station de Génétique Quantitative et Appliquée Equipe de Génétique Statistique 78352 Jouy-en-Josas Cedex France Received 21 March 1990 accepted 3 June 1991 Summary - Data on twin calvings were compared from New Zealand 15 59 cows in 3 selected private herds two Milking Shorthorn and one Friesian and France 216 cows in 11 Maine Anjou pedigree herds . Twin calving rates France only and cumulative numbers of twin calvings per lifetime both countries were obtained for all cows classified according to their sire and dam groups. Dam groups were defined according to the number of twin calvings in the dam s lifetime. In New Zealand the 2 sire groups were defined as follows 1 no daughter producing 2 or more sets of twins 2 at least one such daughter. In France the discrimination was based on the twin calving rate of daughters recorded in the whole population with group 1 below 6 and group 2 over that value. The mean frequencies of cows with at least one set of twins were in the New Zealand herds and in France. In both countries there were significant effects of sire and dam groups but no interaction on a logit scale. In addition the 2 data sets showed a similar increase x to X in frequency of cows producing at least 1 twin set comparing those from dams with twins and those from dams with no twin set. Resultats demonstrated the opportunity of sire selection to improve twin calving performance. The efficiency of selection would also be enhanced by a joint choice of sires dams from prolific groups. cattle twinning I genetics Resume Une comparaison de données génétiques frangaises et néo-zélandaises sur le taux de vêlages gémellaires des bovins. Cel article .
