TAILIEUCHUNG - Báo cáo sinh học: " genetic response possible in dairy cattle improvement by setting up a multiple ovulation and embryo transfer (MOET) nucleus scheme"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: genetic response possible in dairy cattle improvement by setting up a multiple ovulation and embryo transfer (MOET) nucleus scheme | Genet Sei. Evol. 1989 21 169-183 Elsevier INRA 169 Original article The genetic response possible in dairy cattle improvement by setting up a multiple ovulation and embryo transfer MOET nucleus scheme J. Ruane1 and c. Smith 2 11nstitute of Animal Physiology and Genetics Research ABRO West Mains Road Edinburgh EH9 2 University of Guelph Centre for Genetic Improvement of Livestock Guelph Ontario NIG 2W1 Canada received 29 October 1987 accepted 17 June 1988 Summary The genetic response in an efficient progeny testing scheme improving at a constant annual rate of phenotypic standard deviations is compared to that possible from setting up a multiple ovulation and embryo transfer MOET nucleus scheme at a given year zero using bull parents from this scheme as nucleus herd founder animals. Two MOET nucleus schemes are described juvenile with selection before first breeding and adult with selection after first lactation. Four years of selection of bull sires are needed to set up the nucleus herds. Setting up the juvenile nucleus herd is less costly than the adult nucleus herd since only 2 years of selection of bull dams are needed instead of 4. With 8 progeny per donor surviving to selection in the juvenile nucleus scheme the average genetic response of nucleus bulls and commercial cows bom at year 20 is 60 and 53 higher than the corresponding response of breeding males and commercial cows bom in the same year if the progeny iesting scheme is continued. With an adult nucleus scheme responses are 24 and 16 higher. Short-term gains are more substantial from the juvenile than from the adult nucleus scheme. The discounted genetic response of the commercial herd summed over the first 10 years is equivalent for the adult nucleus and progeny testing schemes but is over 40 higher for the juvenile nucleus scheme. When summed over the first 20 years the juvenile scheme proves equally superior. multiple ovulation - embryo transfer - dairy cattle - genetic gain Résumé La .

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